Bone drugs may ward off effects of radiation

Drugs commonly used to strengthen bones to prevent osteoporosis may protect people exposed to radiation against developing leukemia, U.S. researchers said on Sunday.

They said two compounds in a class of drugs called bisphosphonates delayed and in some cases prevented mice exposed to high doses of radiation from developing leukemia, a common long-term side effect of radiation exposure.

Alexandra Miller, a scientist at the Armed Forces Radiobiology Research Institute in Bethesda, Maryland, has been studying ways to protect military personnel and astronauts from radiation exposure.

But she said the findings, which she presented at the American Association for Cancer Research in Denver, Colorado, could also help cancer patients treated with radiation who later develop leukemia as a side effect of their treatment.

The compounds Miller studied are bisphosphonates known as ethane-1-hydroxy-1, 1-bisphosphonate or EHBP, which Miller said is chemically similar to Procter & Gamble's osteoporosis drug Didronel or etidronate.

The other was an experimental drug called CAPBP, which Miller said is similar to Roche's Boniva or ibandronate.

She picked the drugs because of studies in humans that suggest bisphosphonates may help prevent cancer from spreading to the bone. They also have been shown to remove uranium from the body.

Drug delayed, deterred leukemia in mice
Miller exposed lab mice to radiation strong enough to cause leukemia. She injected some of the mice with one of the two compounds and waited.

Typically, mice exposed to radiation developed leukemia and died 92 to 110 days later.

"With the drug, the animals were developing leukemia too, but it took much longer, 150 to 170 days," Miller said in a telephone interview.

"The total number that actually developed leukemia was significantly lower with both of the drugs," she said.

She said all of the untreated animals developed leukemia after radiation exposure, but only about half did in the treated group.

"It was very significant. We didn't have any toxic effects with the drug treatment," she said.

Miller said many more studies would be needed before the drugs could be used in humans, but she thinks the compounds show promise as a way of addressing one of the most toxic side effects of radiation exposure.

Vegetarians show reduced cancer risk

Vegetarians are 12 percent less likely to develop cancer than meat eaters and the advantage is particularly marked when it comes to cancers of the blood, British researchers said on Wednesday.

Past research has shown that eating lots of red or processed meat is linked to a higher rate of stomach cancer and the new study, involving more than 60,000 people, did confirm a lower risk of both stomach and bladder cancer.

But the most striking and surprising difference was in cancers of the blood — such as leukemia, multiple myeloma and non-Hodgkin lymphoma — where the risk of disease was 45 percent lower in vegetarians than in meat eaters.

"More research is needed to substantiate these results and to look for reasons for the differences," Tim Key, study author from the Cancer Research UK epidemiology unit at Oxford University, said.

Key and colleagues, who published their findings in the British Journal of Cancer, followed 61,000 meat eaters and vegetarians for over 12 years, during which time 3,350 of the participants were diagnosed with cancer.

The study, which looked at 20 different types of cancer, found the differences in risk were independent of other factors such as smoking, alcohol intake and obesity, which can all increase the chance of developing cancer.

Gene trigger for deadly skin cancer found

Up to 70 percent of melanoma skin cancers may be triggered by a gene mutation that causes cells to become cancerous after excessive exposure to the sun, researchers said on Monday.

The discovery could lead to better treatments for the most deadly form of skin cancer after scientists at Britain's Institute of Cancer Research established the BRAF gene mutation is often the first event in the cascade of genetic changes leading to melanoma.

Scientists already knew the BRAF gene was frequently damaged in patients with melanoma, but it was unclear if this was a cause or effect of the cancer.

The British institute published its findings in the journal Cancer Cell.

"Our study shows that the genetic damage of BRAF is the first step in skin cancer development," said lead author Richard Marais. "Understanding this process will help us develop more effective treatments for the disease."

The hope is that knowing the genetics behind skin cancer will lead to the development of targeted drugs that can fix the faulty genetic machinery.

While melanoma accounts for only a small percentage of skin cancers, it is responsible for most skin cancer deaths. The disease is characterized by the uncontrolled proliferation of pigment-producing skin cells called melanocytes.

Over-exposure to sunlight is to blame for at least two-thirds of cases as DNA in sunburnt skin cells becomes damaged, leading to the genetic mutations.

Where you live may impact cancer survival

A study of neighborhoods suggests that modifiable factors, not genetics, underlie the racial disparities that have been seen in survival of breast and prostate cancer.

While "large city" studies have shown considerable racial disparities in cancer survival, the new study shows that racial disparities virtually disappear in studies that focus on smaller populations, such as neighborhoods within larger cities.

In their study reported Monday in the journal Cancer, researchers led by Jaymie R. Meliker, of New York's Stony Brook University, asked the question: Do racial disparities in breast and prostate cancer survival seen in large counties persist in small cities and even smaller neighborhoods?

They studied geographic regions in Michigan, using the Michigan Cancer Surveillance Program, which compiled information from 1985 to 2002 on 124,218 breast cancer and 120,615 prostate cancer patients.

As the geographic scale gets smaller, they explain, the population becomes more homogenous in terms of income, access to medical care and other factors that may influence cancer survival. Therefore, the researchers hypothesized that if racial disparities in cancer survival diminished when smaller geographic areas were analyzed, modifiable factors, not genetics, may be responsible for the disparity.

In support of their hypothesis, the study revealed that whites had significantly higher survival rates of prostate and breast cancer compared with blacks when large geographic regions were analyzed. However, when smaller geographic areas were analyzed, such as legislative districts and neighborhoods, disparities diminished or virtually disappeared.

"When racial disparities vanish in small geographic areas, it suggests that modifiable factors are responsible for apparent racial disparities observed at larger geographic scales," Meliker and colleagues write.

It is unclear which modifiable factors are important, but the current findings suggest that genetic factors are not likely to play a large role in disparities of survival from prostate and breast cancer," they conclude.

Wine may help cancer patients handle radiation

A glass of wine a day may help breast cancer patients better tolerate radiation therapy and reduce its adverse effects, according to a new study by an Italian medical university.

The study, released on Wednesday, said polyphenols found in wine may help protect healthy tissues from the effects of radiation while combating cancerous cells.

The research was carried out on 348 women treated for breast cancer between 2003 and 2007 at the radiotherapy and palliative care unit of the Catholic University of Campobasso.

The study at the southern university showed that moderate daily consumption of wine was associated with a 75 percent reduction of skin lesions compared to those who did not drink wine.

"Our data are to be taken with caution as our study was an observational one," said Alessio Morganti, director of the radiotherapy unit.

"A formal randomized trial should now be performed. Establishing the role of wine and its non-alcoholic components is certainly a crucial issue that may open a new way for the preventive use of antioxidants," he said.

The full study is due to be published online in the International Journal of Radiation Oncology Biology Physics.