How to avoid common cancer-causing agents

Recently, the American Cancer Society (ACS) published its first position statement on environmental cancer-causing agents, calling attention to the need for more research on the full impact of all the chemicals floating around in our environment.

The details
People generally associate "environmental factors" that cause cancer with air and water pollutants. However, there are over 100,000 chemicals used in the consumer products that we come in contact with every day, and only a fraction have ever been tested for safety. It's these chemicals the authors would like more attention to be paid to, considering that, the authors note, the World Health Organization's International Agency for Research on Cancer has evaluated just 935 chemicals since it started looking at cancer-causing agents in 1969.

Most of these threats are occupational exposures, which contribute to 2.4 to 4.8 percent of all cancer deaths in this country, but the general population is still exposed at much lower levels. To protect all individuals, the ACS is calling for tighter regulatory standards on both occupational and general exposures, based on sound scientific research that should be better funded, and for greater public disclosure of chemicals being used so that individuals can make informed decisions. The society is also calling for more detailed research on a chemical's cumulative-exposure risk, as well as how that risk is influenced by dosing and timing, and for monitoring the accumulation of these chemicals in humans and in the food chain.

What it means
"The environment as it influences health is far more broad than the public may think," says Jonathan Samet, MD, MS, professor in the department of preventive medicine at the University of Southern California's Keck School of Medicine and co-chair of the ACS Subcommittee on Cancer and the Environment, which authored the report. Unfortunately, he adds, cancer-causing agents are often shrouded in uncertainty. "Cellphones are particularly salient examples of environmental exposures that are now ingrained in modern life, yet there's an uncertainty of whether they're a cause of brain cancer," he says.

The ACS is concerned about the environment and cancer, but "there's definitely a need for better and more efficient ways to test for toxicity." The report, he adds, was intended to put environmental pollutants into the broader context of cancer prevention, which, along with more stringent testing of chemicals, includes cutting down on tobacco use, improving diet and exercise, and employing vaccines against infections that cause cancer, such as hepatitis B and the human papillomavirus (HPV).

Despite the stew of chemicals we encounter on a daily basis, there are ways to protect yourself from their carcinogenic effects:

Stop smoking
Smoking contributes to 30 percent of all cancer-related deaths in the general population, the authors note, making it the most controllable source of cancer-causing agents. There's plenty of free help available for quitting; start by talking to your doctor or calling the ACS at 800-ACS-2345.

Have your home tested for radon
Radon, a colorless, odorless gas that seeps into homes via cracks in foundations, is the leading cause of non-smoking-related lung cancer in the U.S. It's a byproduct of the natural breakdown of uranium in soil, and some regions of the country have higher instances than others. Visit www.epa.gov/radon to learn if you're in a high-risk area for radon poisoning.

Get vaccinated or screened
The ACS says that 17 percent of cancer deaths are caused by viruses and other infections. Make sure you follow the screening guidelines that are appropriate for your age, gender, and health status. And get your kids the proper screenings, too. Hepatitis B vaccines are generally part of a child's routine vaccination schedule, but the HPV vaccine is administered around the time a girl turns 12. Whether or not you choose to get your kids vaccinated, teach them the value of regular screenings that can catch these infections before they turn into cancer.

Eat organic
Pesticides have been linked to childhood leukemia and breast cancer, among other problems. Choose food that's grown with organic techniques whenever possible, and you'll keep suspect chemicals out of your body. Voting organic with your dollars also decreases the amount of agrichemicals that end up in our water and soil.

Clean naturally
Like pesticides, harsh chemicals in cleaning products have been linked to a wide variety of health problems and some are suspected of causing cancer. Since cleaning companies aren't required to tell you what's in their products, the simplest way to avoid cancer-causing agents is to make your own cleaners using natural ingredients like vinegar. You should also avoid home care products that contain chemical fragrances, which may be listed as "parfum" or "fragrance" on the label.

Many high-risk women reject breast MRIs

CHICAGO - As many as 42 percent of women who are at intermediate or high risk of getting breast cancer decide not to get recommended MRI screening, even if it is offered for free, U.S. researchers said on Tuesday.

A quarter of the women in the study who were offered the free screening test decided not to get it because they feel claustrophobic in the tunnel-like scanners. But many also said they declined because of costs involved if the test reveals something that needs to be followed up.

Some said they simply could not spare the time.

"Very early on we were surprised to notice that very few women would accept that invitation, even though it would be no cost to them," said Dr. Wendie Berg, a breast imaging specialist at American Radiology Services in Lutherville, Maryland, and Johns Hopkins University, whose study appears in the journal Radiology.

Her team studied the reasons why high-risk women who are recommended for the more sensitive MRI breast screening test do not get it.

Magnetic resonance imaging, or MRI, can help identify early breast cancer in high-risk women who tend to develop cancer earlier than women at average risk.

For the study, they identified 1,215 women who were at intermediate or high risk for breast cancer and were taking part in larger clinical trial.

All of the women were at increased risk for breast cancer, but even in a group of high risk women, who have a 25 percent greater lifetime risk of breast cancer because of they have known or suspected genetic mutations in the BRCA1 or BRCA2 genes, the willingness to undergo a breast MRI was limited.

"About 20 percent of our patients fall into that category," Berg said. "We would have expected virtually 100 percent participation in the study."

Berg said the chief reason women gave for not wanting a breast MRI was because they feel claustrophobic in the tunnel-like machines.

"That has been a common issue in MRI of the breast and other areas as well. It is usually something that can be overcome with sedation but it is still an issue," she said.

Of the 512 women who declined, 25.4 percent refused because of claustrophobia, 18.2 percent cited time constraints, 12 percent cited financial concerns if the tests identifies any cancers or has false-positive results, 9.2 percent said their doctor would not refer them and 7.8 percent said it was because they were not interested.

Women who are at high risk for breast cancer currently are recommended to get a yearly mammogram and an MRI test.

Berg said the study points to the need for alternative ways of screening high-risk women, including training more experts in breast ultrasound, a quicker, more convenient test.

More than 400,000 women in the world die from breast cancer each year.

Maine to consider cell phone cancer warning

AUGUSTA, Maine - A Maine legislator wants to make the state the first to require cell phones to carry warnings that they can cause brain cancer, although there is no consensus among scientists that they do and industry leaders dispute the claim.

The now-ubiquitous devices carry such warnings in some countries, though no U.S. states require them, according to the National Conference of State Legislators. A similar effort is afoot in San Francisco, where Mayor Gavin Newsom wants his city to be the nation's first to require the warnings.

Maine Rep. Andrea Boland, D-Sanford, said numerous studies point to the cancer risk, and she has persuaded legislative leaders to allow her proposal to come up for discussion during the 2010 session that begins in January, a session usually reserved for emergency and governors' bills.

Boland herself uses a cell phone, but with a speaker to keep the phone away from her head. She also leaves the phone off unless she's expecting a call. At issue is radiation emitted by all cell phones.

Under Boland's bill, manufacturers would have to put labels on phones and packaging warning of the potential for brain cancer associated with electromagnetic radiation. The warnings would recommend that users, especially children and pregnant women, keep the devices away from their head and body.

The Federal Communications Commission, which maintains that all cell phones sold in the U.S. are safe, has set a standard for the "specific absorption rate" of radiofrequency energy, but it doesn't require handset makers to divulge radiation levels.

The San Francisco proposal would require the display of the absorption rate level next to each phone in print at least as big as the price. Boland's bill is not specific about absorption rate levels, but would require a permanent, nonremovable advisory of risk in black type, except for the word "warning," which would be large and in red letters. It would also include a color graphic of a child's brain next to the warning.

While there's little agreement about the health hazards, Boland said Maine's roughly 950,000 cell phone users among its 1.3 million residents "do not know what the risks are."

All told, more than 270 million people subscribed to cellular telephone service last year in the United States, an increase from 110 million in 2000, according to CTIA-The Wireless Association. The industry group contends the devices are safe.

"With respect to the matter of health effects associated with wireless base stations and the use of wireless devices, CTIA and the wireless industry have always been guided by science, and the views of impartial health organizations. The peer-reviewed scientific evidence has overwhelmingly indicated that wireless devices do not pose a public health risk," said CTIA's John Walls.

James Keller of Lewiston, whose cell phone serves as his only phone, seemed skeptical about warning labels. He said many things may cause cancer but lack scientific evidence to support that belief. Besides, he said, people can't live without cell phones.

"It seems a little silly to me, but it's not going to hurt anyone to have a warning on there. If they're really concerned about it, go ahead and put a warning on it," he said outside a sporting good store in Topsham. "It wouldn't deter me from buying a phone."

While there's been no long-term studies on cell phones and cancer, some scientists suggest erring on the side of caution.

Last year, Dr. Ronald B. Herberman, director emeritus of the University of Pittsburgh Cancer Institute, sent a memo to about 3,000 faculty and staff members warning of risks based on early, unpublished data. He said that children should use the phones only for emergencies because their brains were still developing and that adults should keep the phone away from the head and use a speakerphone or a wireless headset.

Herberman, who says scientific conclusions often take too long, is one of numerous doctors and researchers who have endorsed an August report by retired electronics engineer L. Lloyd Morgan. The report highlights a study that found significantly increased risk of brain tumors from 10 or more years of cell phone or cordless phone use.

Also, the BioInitiative Working Group, an international group of scientists, notes that many countries have issued warnings and that the European Parliament has passed a resolution calling for governmental action to address concerns over health risks from mobile phone use.

But the National Cancer Institute said studies thus far have turned up mixed and inconsistent results, noting that cell phones did not come into widespread use in the United States until the 1990s.

"Although research has not consistently demonstrated a link between cellular telephone use and cancer, scientists still caution that further surveillance is needed before conclusions can be drawn," according to the Cancer Institute's Web site.

Motorola Inc., one of the nation's major wireless phone makers, says on its Web site that all of its products comply with international safety guidelines for radiofrequency energy exposure.

A Motorola official referred questions to CTIA.

First gene maps created for 2 deadly cancers

LONDON - Scientists have identified all the changes in cells of two deadly cancers to produce the first entire cancer gene maps and say the findings mark a "transforming moment" in their understanding of the disease.

The studies by international scientists and Britain's Wellcome Trust Sanger Institute are the first comprehensive descriptions of tumor cell mutations and lay bare all the genetic changes behind melanoma skin cancer and lung cancer.

"What we are seeing today is going the transform the way that we see cancer," Mike Stratton of the Sanger Institute's cancer genome project told a briefing in London. "We have never seen cancer revealed in this form before."

The scientists sequenced all the DNA from both tumor tissue and normal tissue from a melanoma patient and a lung cancer patient using a technology called massively parallel sequencing. By comparing the cancer sequences with the healthy ones, they were able to pick up all the changes specific to cancer.

The lung tumor carried more than 23,000 mutations and the melanoma had more than 33,000.

Peter Campbell, also of the Sanger Institute, said the lung cancer study suggests a typical smoker develops one mutation for every 15 cigarettes smoked and the damage starts with the first puff. Lung cancer kills around 1 million people worldwide each year and 90 percent of cases are caused by smoking.

"These catalogues of mutations are telling us about how the cancer has developed — so they will inform us on prevention — and they include all the drivers, which tell us about the processes that are disrupted in the cancer cell which we can try and influence through our treatments," Stratton said.

But the scientists said identifying all the drivers — the mutations that cause cells to become cancerous — would take far more work and it could be several years yet before any new targets are found for the development of new cancer drugs.

"Somewhere among the mutations we have found lurk those that drive the cells to become cancerous," said Andy Futreal, who also worked on the studies. "Tracking them down will be our major challenge for the next few years."

Scientists have already identified some genetic mutations linked to cancers — mutations of a gene called BRAF are found in melanoma and new drugs to block its cancer causing activity are already in development.

Drugs such as Roche AG's Herceptin and AstraZeneca's Iressa also target tumor cells that carry specific mutations.

Aim is to make genetic maps of all cancers
Stratton said the aim now was to produce genetic maps of all types of cancer. There are more than 100 cancers in all, and each genome mapping process requires several months of work and costs tens of thousands of dollars.

The first 50 cancers are to be mapped by scientists working in International Cancer Genome Consortium (ICGC), launched 2008, which includes the U.S. National Institutes of Health as well as cancer and genetic research groups from Australia, Canada, China, France, India, Japan and Singapore.

Mark Walport, director of the Wellcome Trust, said the cancer gene maps would drive further medical advances.

With ever improving technology to map genomes, and costs falling fast, the scientists said in future each cancer patient could have a complete genome catalog to help doctors pick the right treatments for individual cases.

"The is the first glimpse of the future of cancer medicine, not only in the laboratory, but eventually in the clinic," Walport said.

15,000 will die from CT scans done in 1 year

CHICAGO - Radiation from CT scans done in 2007 will cause 29,000 cancers and kill nearly 15,000 Americans, researchers said Monday.

The findings, published in the Archives of Internal Medicine, add to mounting evidence that Americans are overexposed to radiation from diagnostic tests, especially from a specialized kind of X-ray called a computed tomography, or CT, scan.

"What we learned is there is a significant amount of radiation with these CT scans, more than what we thought, and there is a significant number of cancers," said Dr. Rita Redberg, editor of the Archives of Internal Medicine, where the studies were published

"It's estimated that just from the CT scans done in one year, just in 2007, there will be 15,000 excess deaths," Redberg said in a telephone interview.

"We're doing millions of CT scans every year and the numbers are increasing. That is a lot of excess deaths."

CT scans give doctors a view inside the body, often eliminating the need for exploratory surgery. But CT scans involve much higher radiation dose than conventional X-rays. A chest CT scan exposes the patient to more than 100 times the radiation dose of a chest X-ray.

70 million scans done in 2007
About 70 million CT scans were done on Americans in 2007, up from 3 million in 1980. Amy Berrington de Gonzalez of the National Cancer Institute and colleagues developed a computer model to estimate the impact of so many scans.

They estimated the scans done in 2007 will cause 29,000 cancers. A third of the projected cancers will occur in people who were ages 35 to 54 when they got their CT, two-thirds will occur in women and 15 percent will arise from scans done in children or teens.

The researchers estimated there will be an extra 2,000 excess breast cancers just from CT scans done in 2007.

Redberg, who wrote a commentary on the studies, said U.S. doctors' enthusiasm for the tests has led to an explosion in their use that is putting patients at risk.

"While certainly some of the scans are incredibly important and life saving, it is also certain that some of them were not necessary," Redberg said.

In a separate study, Dr. Rebecca Smith-Bindman of the University of California, San Francisco, and colleagues analyzed data from 1,119 patients undergoing the 11 most common types of diagnostic CT scans at four institutions in 2008.

They found radiation dosage varied widely between different types of CT studies, from a median or midpoint of 2 millisieverts for a routine head CT scan to 31 millisieverts for a scan of the abdomen and pelvis, which often involves taking multiple images of the same organ.

By comparison, the average American is exposed to about 3 millisieverts of radiation a year from ground radon or flying in an airplane — a level not considered a risk to health.

The researchers said efforts need to be taken to minimize CT radiation exposure, including reducing the number of unnecessary tests, cutting the dose per study, and standardizing the doses across facilities.

Imaging equipment makers such as GE Healthcare, Siemens, Philips and Toshiba Medical Systems are working to develop low-dose CT scanners.

Poor turned away from free cancer screenings

ALBANY, N.Y. - As the economy falters and more people go without health insurance, low-income women in at least 20 states are being turned away or put on long waiting lists for free cancer screenings, according to the American Cancer Society's Cancer Action Network.

In the unofficial survey of programs for July 2008 through April 2009, the organization found that state budget strains are forcing some programs to reject people who would otherwise qualify for free mammograms and Pap smears. Just how many are turned away isn't known; in some cases, the women are screened through other programs or referred to different providers.

"I cried and I panicked," said Erin LaBarge, 47. This would have been her third straight year receiving a free mammogram through the screening program in St. Lawrence County. But the Norwood, N.Y., resident was told she couldn't get her free mammogram this year because there isn't enough money and she's not old enough.

New York used to screen women of all ages, but this year the budget crunch has forced them to focus on those considered at highest risk and exclude women under 50.

"It's a scary thought. It really is," said LaBarge, who fears she's at a higher risk because her grandmother died of breast cancer.

The Cancer Society doesn't have an estimate for what percentage of breast cancer diagnoses come from mammogram screenings, but says women have a 98 percent survival rate when breast cancer is caught early, during stage I. That shrinks to about 84 percent during stages II and III, and just 27 percent at stage IV — when cancer has reached its most advanced point.

"I already know there are women who are dying whose lives we could have saved with mammography and other detections," said Dr. Otis Brawley, chief medical officer for the society.

15,000 fewer projected in N.Y.
In New York, the Cancer Society says providers in Manhattan, Brooklyn and western Queens, and in Nassau, Suffolk and Westchester counties project they'll perform nearly 15,000 fewer free mammograms for the fiscal year ending April 2010, compared with the previous year.

The Cancer Society has no way to count how many women are being turned away, and many providers don't keep track of how many are denied screening, or whether those women find another alternative. The cost of screening varies, but the average mammogram is about $100, while a Pap screen can range between $75 and $200, according to the society.

Project Renewal Van Scan, which gives mammograms around New York City, usually targets 6,000 women a year but has cut back to 3,100 this year, director Mary Solomon said.

Each state handles free screenings differently. Some use state funds to supplement federal funding, while others get private assistance from the Susan G. Komen for the Cure foundation and other groups.

At least 14 states cut budgets for free cancer screenings this year: Colorado, Montana, Illinois, Alabama, Minnesota, Connecticut, South Carolina, Utah, Missouri, Washington, Ohio, Massachusetts, Pennsylvania and Arkansas.

Some states that have cut their budgets have found ways to maintain services; some states that haven't reduced their budgets still find themselves having to turn women away because they don't have enough funding.

"This is rationing of health care by offering (screenings) only in the first half of the fiscal year, or by cutting back on those programs," Brawley said. "It's rationing that is leading to people dying."

New York, which has fought for two years with deficits in the billions, used to screen women of all ages for breast cancer, but after $3.5 million in budget cuts this year, women under 50 — like LaBarge — are no longer eligible unless they have the breast cancer gene or a serious family cancer history. Despite LaBarge's family history, she was denied screening because of her age and a lack of funding.

"We don't do this lightly," said Claudia Hutton, spokeswoman for the agency. "This is not a cut that we would have made if the state had the money, but the state just does not have the money."

Chemo boosts cancer survival in older women

CHICAGO - Chemotherapy helps improve breast cancer survival in post-menopausal women, adding to a long-standing debate about how best to treat these women, U.S. researchers said Thursday.

A gene-based test called Oncotype DX made by Genomic Health Inc may help identify a small group of women who are not likely to benefit from chemotherapy, a second study found.

The main study proves that adding chemotherapy to treatment with the estrogen-blocking drug tamoxifen can help prevent cancer from coming back in women with estrogen-receptor positive breast cancers, the most common kind in which a hormone is driving the cancer.

"We have a survival benefit that lasts for a very long time ... for women who got both modalities of treatment versus women who just got tamoxifen," said Dr. Kathy Albain of Loyola University Health System in Maywood, Illinois.

She presented findings from both studies at the American Association for Cancer Research San Antonio Breast Cancer Symposium.

"It is considered a landmark study in the clinical trials literature because it is the only one really demonstrating the survival advantage of chemotherapy added to tamoxifen," Albain said in a telephone interview.

"Up until this trial, studies adding common chemotherapy drugs to tamoxifen or tamoxifen alone were essentially negative."

For the study, the team followed nearly 1,500 post-menopausal women with estrogen-receptor positive breast cancers that had spread to at least one lymph node.

Some of the women got both tamoxifen and a chemotherapy drug known as anthracycline, and some got tamoxifen alone.

The team found that the women who got the chemotherapy were 24 percent less likely to have their cancer come back.

They were also 17 percent less likely to die during the 10-year study period, but this finding was just shy of meeting statistical significance.

The team also found that giving tamoxifen after chemotherapy ended instead of during chemotherapy improved a woman's survival chances.

In a second study led by Albain, published in the journal Lancet Oncology, the team evaluated whether the Oncotype DX test can predict which women would benefit from chemotherapy.

The test examines 21 genes from a tumor sample to see how active they are, and produces a score that predicts chemotherapy benefit. It is most commonly used in women with estrogen-fed tumors whose cancer has not spread to a lymph node.

But Albain's study suggests it may also be useful in identifying women whose tumors had spread that would not benefit from chemotherapy.

Albain said a large clinical trial is getting started that will confirm whether the test is effective, but that will be expensive and take many years.

Meanwhile, she said, some doctors like herself plan to use the test on certain patients to give them more choices about their breast cancer treatment options.

Drug combo lengthens breast cancer survival

SAN ANTONIO - Some women with very advanced breast cancer may have a new treatment option. A combination of two drugs that more precisely target tumors significantly extended the lives of women who had stopped responding to other medicines, doctors reported Friday.

It was the first big test of combining Herceptin and Tykerb. In a study of 300 patients, women receiving both drugs lived nearly five months longer than those given Tykerb alone.

Doctors hope for an even bigger benefit in women with less advanced disease, and were elated at this much improvement for very sick women who were facing certain death.

"We don't see a lot that works in patients who have seen six prior therapies as they did in this trial, so that alone is exciting," said Dr. Jennifer Litton, a breast cancer specialist at the University of Texas M. D. Anderson Cancer Center.

The good results are in stark contrast to two other studies that found no survival advantage from Avastin, a $30,000-a-month drug whose approval for breast cancer patients was very controversial.

Considering Avastin's potential side effects — blood clots in the lungs, poor wound healing, kidney problems — a survival benefit "would have made the cost of the drug less painful to take," Litton said.

She had no role in any of the studies, which were reported Friday at the San Antonio Breast Cancer Symposium.

Herceptin and Tykerb aim at a protein called HER-2 that is made in abnormally large quantities in about one-fourth of all breast cancers. Herceptin blocks the protein on the cell's surface; Tykerb does it inside the cell.

"It's kind of like having a double brake on your tumor. If the first one fails, the second one does the job," said the Dr. Kimberly Blackwell of Duke University. She led the combo treatment study and has consulted for its sponsor, British-based GlaxoSmithKline PLC, which makes Tykerb, and for Genentech, which makes Herceptin and Avastin.

Women in the study had already received Herceptin alone or with various chemotherapy drugs and still were getting worse. They were randomly assigned to receive only Tykerb or both drugs, to see whether the combo might help Herceptin regain its effectiveness.

Median survival was analyzed after about three-fourths of the women had died — roughly two years after the study began. It was 61 weeks in the combo group versus 41 for those taking only Tykerb.

That likely underestimates the combo's true benefit because women on Tykerb alone were allowed to add Herceptin partway through the study if they continued to worsen, and many of them did, Blackwell said.

One woman on the combo in the study suffered a fatal blood clot. The only other common, serious side effect was diarrhea, which plagued 7 to 8 percent of each group. Herceptin costs about $10,000 a month; Tykerb, $5,000 to $6,000.

Stephanie Will gets the drugs for free from the U.S. Army at Fort Bragg, N.C., where her husband is based. She was only 30 years old and nursing her third child when her cancer was found in 2003. She received the combo treatment as part of the study.

"It's been three years and four months, and it's been stable," Will said of her cancer. The combo has been easy to take compared to other treatments, she said. "It's allowed me to live my life pretty normally."

Dr. Eric Winer, breast cancer chief at the Dana-Farber Cancer Center in Boston, said several studies now show that Herceptin still helps women even when their cancers seem to be getting worse.

"Herceptin is like a big roadblock on a superhighway. Eventually the cancer finds a way around it by taking an off ramp. But it's much less efficient to take that off ramp, so Herceptin is still having some influence on that cancer," said Winer, who, like Litton, has no financial ties to any drugmakers.

"Herceptin is a drug that keeps on giving," he said.

Not so for Avastin, which works by crimping a tumor's blood supply. The federal Food and Drug Administration approved its use in women whose cancers had spread beyond the breast over the objections of FDA advisers who wanted more evidence of benefit for these patients.

Now, two big international studies show that Avastin modestly delayed the time breast cancer took to worsen, but had no effect on overall survival:

• A 684-patient study of Avastin with chemotherapy as a second-try treatment for women whose cancers do not respond to Herceptin.
• A 736-patient study of Avastin plus Taxotere or a dummy drug as first-time treatment for cancers that had recurred or spread beyond the breast.

Avastin also is approved to treat certain lung, brain and colon cancers, and the new studies have no bearing on its use in those patients.

The cancer conference is sponsored by the American Association for Cancer Research, Baylor College of Medicine and the UT Health Science Center.

Study finds benefits of soy after breast cancer

Is soy food helpful or harmful for women with breast cancer? Studies have yielded mixed results. A new study published today suggests that breast cancer survivors may benefit from eating moderate amounts of soy products.

In a large group of breast cancer survivors in China, researchers found that a higher intake of soy food — up to 11 grams daily — was associated with a lower risk of death or recurrence of breast cancer during follow up. (For comparison, a slice of bread generally weighs between 30 and 40 grams.)

"The key take home message from our study is that moderate amount of soy food intake is safe and may reduce risk of mortality and recurrence among women with breast cancer," Dr. Xiao Ou Shu, of Vanderbilt University Medical Center in Nashville, Tennessee noted in an email to Reuters Health.

Soy foods are rich in compounds called isoflavones — a major group of plant-derived phytoestrogens possessing both estrogen-like and anti-estrogen actions.

Eating soy has been linked to a reduced of risk of breast cancer in some studies, while other studies have suggested that soy may help breast cancer cells grow and multiply, the study team explains in Wednesday's issue of the Journal of the American Medical Association.

To investigate further, Shu and colleagues analyzed the dietary habits of more than 5,000 women aged 20 to 75 years who were diagnosed with breast cancer between March 2002 and April 2006 and were followed up through June 2009 as part of the Shanghai Breast Cancer Survival Study.

Among 5,033 women who had surgery to remove the breast cancer, 444 women died and 534 had recurrences or breast cancer-related deaths during a median of 3.9 years.

Women who ate the most soy protein had a 29 percent lower risk of dying during the study period, and a 32 percent lower risk of having their cancer return compared to women who ate the least amount of soy protein.

At 4 years, death rates were 10.3 percent and 7.4 percent for women with the lowest and highest intakes of soy protein, and recurrence rates at 4 years were 11.2 percent and 8.0 percent, respectively.

The benefits of soy food intake on death and breast cancer recurrence peaked at 11 grams per day, the researchers note. "No additional benefits on mortality and recurrence were observed with higher intakes of soy food," they wrote.

Eating soy was beneficial regardless of whether the women's breast tumors were driven by estrogen (that is, estrogen-receptor positive breast cancer) or were "estrogen receptor-negative."

The benefits of soy were also seen in both users and nonusers of tamoxifen, a drug commonly used to treat and prevent breast cancer. Prior studies have suggested that soy isoflavones may interact with tamoxifen, and both beneficial and possibly harmful interactions have been reported.

The authors of a commentary on the study caution that while it provides important information, there are several concerns, including differences in the quality, type and quantity of soy food intake between Chinese and American women.

For one thing, the average isoflavone intake in Chinese women is 47 milligrams per day compared with 1 to 6 milligrams per day for American women, Dr. Rachel Ballard-Barbash, of the National Cancer Institute, Bethesda, Maryland and Dr. Marian L. Neuhouser, of the Fred Hutchinson Cancer Research Center, Seattle, point out.

Larger studies, they say, are needed to understand the effects of these foods among diverse subsets of women with breast cancer.

In the meantime, they add, women with breast cancer should know that "soy foods are safe to eat and that these foods may offer some protective benefit for long-term health."

"Patients with breast cancer can be assured that enjoying a soy latte or indulging in pad thai with tofu causes no harm and, when consumed in plentiful amounts, may reduce risk of disease recurrence," Ballard-Barbash and Neuhouser advise.

They point out, however, that any potential benefits are from soy foods. Inferences should not be made about the risks or benefits of soy-containing dietary supplements.

Colon cancer deaths could make big drop

ATLANTA - Colon cancer deaths could drop dramatically in the next decade because of better screening and treatment, according to an optimistic new prediction by top researchers.

The estimate was made in an annual report that shows that, overall, the U.S. cancer death rate is continuing to decline, as it has since the 1990s.

The report released Monday focuses largely on cancers of the colon and rectum, which together are the third leading cancer killer in the United States. An estimated 50,000 people will die from it this year.

The battle against colorectal cancer has been a growing success story: The death rate dropped roughly 20 percent in the last 10 years, according to American Cancer Society figures.

The new report — by researchers at the advocacy group and other organizations — predicts that death rate will drop even more over the next decade. By 2020, the rate could be half what it was in 2000, they said.

Too optimistic?
The prediction assumes colon cancer screening and improved chemotherapy treatment will become more and more common, and colon cancer contributors like smoking and red meat consumption will decline.

The prediction is “optimistic but realistic,” said Elizabeth Ward, who oversees surveillance and health policy at the American Cancer Society.

But some other experts said such a large drop could require far-reaching changes in how many people eat a healthier diet, have health insurance and can get good medical care.

“I think it’s a little bit more optimistic than realistic,” said Dr. Edward J. Benz Jr., president of the Dana-Farber Cancer Institute in Boston.

The new report looks at cancer trends from 1975 through 2006. The Cancer Society and others reported 2006 cancer death statistics in May, but this report provides further analysis and adds the predictions about colorectal cancer.

Cancer is the nation’s No. 2 killer, behind heart disease, and accounts for nearly a quarter of annual deaths.

Lung cancer accounted for nearly 30 percent of cancer deaths in 2006. Cancers of the colon and rectum accounted for 10 percent, breast cancer in females about 7 percent and prostate cancers in men about 5 percent.

While deaths rates from many of the major cancers have been declining, the rate for liver cancer has been increasing. In women, deaths from pancreatic cancer are rising. In men, esophageal cancer and melanoma deaths are increasing.

There are differences among different racial and ethnic groups. Overall, cancer death rates are highest in black men and women. But pancreatic cancer death rates have been increasing for whites and not blacks.

But overall, cancer diagnoses and death rates have declined significantly, a success attributed largely to improvements in screening and treatment and declines in smoking.

The colorectal cancer death rate was about 17 deaths per 100,000 people in 2006. Better chemotherapy drugs have been used along with surgery to improve survival. And as of 2005, about half of U.S. adults aged 50 or older had had a recommended screening, such as a colonoscopy within the last 10 years or a stool blood test within the last year.

“It seems to me that it’s a cascade of things that include medical science and technology advances,” said Dr. Michael Fisch, head of general oncology at the University of Texas M. D. Anderson Cancer Center in Houston.

The report’s prediction is based on a number of assumptions. Among other things, it assumes that the number of people who are screened will increase, fewer people will smoke or eat red meat more than twice a week, and the obesity rate will hold about steady.

Doctors say smoking and obesity contribute to colorectal cancer deaths, by increasing the odds of getting cancer or making treatment more difficult. While the U.S. adult smoking rate has gradually been declining for decades, the obesity rate has been climbing.

The new report was put together by the Cancer Society, the National Cancer Institute, the Centers for Disease Control and Prevention and the North American Association of Central Cancer Registries.

It’s being published in the journal Cancer.

No cell phone, brain tumor link, study says

WASHINGTON - A very large, 30-year study of just about everyone in Scandinavia shows no link between cell phone use and brain tumors, researchers reported on Thursday.

Even though mobile telephone use soared in the 1990s and afterward, brain tumors did not become any more common during this time, the researchers reported in the Journal of the National Cancer Institute.

Some activist groups and a few researchers have raised concerns about a link between cell phones and several kinds of cancer, including brain tumors, although years of research have failed to establish a connection.

"We did not detect any clear change in the long-term time trends in the incidence of brain tumors from 1998 to 2003 in any subgroup," Isabelle Deltour of the Danish Cancer Society and colleagues wrote.

Deltour's team analyzed annual incidence rates of two types of brain tumor — glioma and meningioma — among adults aged 20 to 79 from Denmark, Finland, Norway, and Sweden from 1974 to 2003. These countries all have good cancer registries that keep a tally of known cancer cases.

This represented virtually the entire adult population of 16 million people, they said.

Over the 30 years, nearly 60,000 patients were diagnosed with brain tumors.

"In Denmark, Finland, Norway, and Sweden, the use of mobile phones increased sharply in the mid-1990s; thus, time trends in brain tumor incidence after 1998 may provide information about possible tumor risks associated with mobile phone use," the researchers wrote.

They did see a small, steady increase in brain tumors, but it started in 1974, long before cell phones existed.

"From 1974 to 2003, the incidence rate of glioma increased by 0.5 percent per year among men and by 0.2 percent per year among women," they wrote.

Incidence of meningioma tumors rose by 0.8 percent a year among men, and rose by 3.8 percent a year among women starting in the mid-1990s. But this was mostly among women over the age of 60, who were already among those most likely to have brain tumors, they noted.

In addition, it became easier to diagnose these tumors because of better types of brain scans.

Overall, there was no significant pattern, they said.

"No change in incidence trends were observed from 1998 to 2003," they added. That would have been when tumors would start showing up, assuming it took five to 10 years for one to develop, they said.

It is possible, Deltour's team wrote, that it takes longer than 10 years for tumors caused by mobile phones to turn up, that the tumors are too rare in this group to show a useful trend, or that there are trends but in subgroups too small to be measured in the study.

It is just as possible that cell phones do not cause brain tumors, they added.

Most scientific studies show no association between cell phone use and brain tumors and researchers trying to find a connection have failed to find any biological explanation for how a mobile phone might cause cancer.

"Because of the high prevalence of mobile phone exposure in this population and worldwide, longer follow-up of time trends in brain tumor incidence rates are warranted," Deltour's team advised.

Tracking tumors on CTs can predict lung cancer

BOSTON - Small or slow-growing nodules discovered on a lung scan are unlikely to develop into tumors over the next two years, researchers reported on Wednesday.

The findings, reported in the New England Journal of Medicine, could help doctors decide when to do more aggressive testing for lung cancer. They could also help patients avoid unnecessarily aggressive and potentially harmful testing when lesions are found.

Lung cancer, the biggest cancer killer in the United States and globally, is often not diagnosed until it has spread. It kills 159,000 people a year in the United States alone.

The work is part of a larger effort to develop guidelines to help doctors decide what to do when such growths, often discovered by accident, appear in a scan.

High-tech X-rays called CT scans can detect tumors — but they see all sorts of other blobs that are not tumors, and often the only way to tell the difference is to take a biopsy, a dangerous procedure.

Tested guidelines for dealing with the nodules do not exist, said Dr. James Mulshine of Rush University Medical Center in Chicago and David Jablons of the University of California San Francisco Cancer Center, in a Journal editorial.

Good guidelines could help make lung cancer screening practical, Dr. Rob van Klaveren of the Erasmus Medical Center in Rotterdam, the Netherlands, who led the new study, said in a telephone interview.

At the moment, routine lung cancer screening is considered impractical because of its high cost and because too many healthy people are called back for further testing.

"All these recall CT scans give rise to a lot of anxiety," said van Klaveren.

Screening
The team looked at 7,557 people at high risk for lung cancer because they were current and former smokers. All received multidetector CT scans that measured the size of any suspicious-looking nodules.

Volunteers who had nodules over 9.7 millimeters in width, or had growths of 4.6 millimeters that grew fast enough to more than double in volume every 400 days, were sent for further testing. Of the 196 people who fell into that category, 70 were found to have lung cancer; 10 additional cases were found years later.

But of the 7,361 who tested negative during screening, only 20 lung cancer cases later developed.

In a second round of screening, done one year after the first, 1.8 percent were sent to the doctor because they had a nodule that was large or fast-growing. More than half turned out to have lung cancer.

The result means that if the screening test says you don't have lung cancer, you probably don't, the researchers said. "The chances of finding lung cancer one and two years after a negative first-round test were 1 in 1,000 and 3 in 1,000 respectively," they concluded.

The study is part of a larger project, known as NELSON, designed to see if a screening program can, over the long term, cut lung cancer death rates by 25 percent. Final results are expected in 2015.

Breast-screening debate splits along party lines

WASHINGTON - Republican lawmakers pressed their case on Wednesday that new U.S. recommendations advising against routine mammograms for women in their 40s could be used to ration health care under reform legislation before Congress, a charge Democrats denied.

The guidelines, issued on Nov. 16 by the U.S. Preventive Services Task Force, a federal scientific advisory panel, scaled back recommendations for annual mammograms to screen for breast cancer in women in their 40s with an average risk for the disease.

The guidelines touched off a debate among cancer doctors.

Many groups, including the American Cancer Society, said they would stick by their current recommendations of starting annual mammogram screening at age 40 because the breast X-rays have been proven to save lives by spotting tumors early on when they are most easily treated.

During a congressional hearing, Republican Representative Joe Barton argued that under Democratic healthcare reform legislation passed by the House of Representatives, the task force could determine what preventive services, including mammograms, would be covered for many Americans.

"To have a task force make the recommendation that has been made, and to have in this bill the authority that's given to various unelected bureaucrats to make health care decisions, including coverage frequency, in my opinion, is wrong," Barton told a hearing of the House Energy and Commerce Committee's subcommittee on health.

The Senate is debating its version of health care reform legislation, President Barack Obama's top domestic priority.

'Don't want rationing'
"We don't want rationing of health care in America. We don't want to intervene between the doctor-patient relationship. We don't want young women, or for that matter, more mature women over the age of 74, developing breast cancer because they're not allowed a mammogram," Barton said.

Democratic lawmakers dismissed the Republican concerns and said if healthcare reform legislation is not passed, many women would die from breast cancer because they lack any health insurance and do not get any preventive care.

"Nothing in this legislation prohibits insurance companies from covering mammograms," Democratic Representative Zack Space told the panel.

"This bill makes preventive care a basic and fundamental right for every American," he said.

Democratic Representative John Sarbanes said, "To me, the discussion today is not about rationing. It's about being rational, about looking at all the evidence that is available to us and making a smart decision about what the coverage should be. I think the jury is out."

The task force's recommendations, which are based on computer models, attempted to balance the benefits of detecting breast cancer early with the potential harms of tests, treatments and worry to women who get false positive results.

Dr. Ned Calonge, chairman of the task force that issued the recommendations, said the timing of the guidelines -- landing in the middle of the heated congressional healthcare reform debate -- was unfortunate. Calonge admitted the guidelines were communicated poorly.

"Politics play no part in our processes. Cost and cost effectiveness were never considered in our discussions. We voted on these breast cancer screening recommendations in June of 2008 — long before the last presidential election and any serious discussion of national health reform," Calonge said.