(December 3, 2009 - Insidermedicine)

From Philadelphia - According to a report published in the journal Cancer Epidemiology, Biomarkers & Prevention, scientists have identified a strong connection between cigarette smoking and colorectal cancer. For 13 years, researchers followed over 180,000 people aged 50-74. They found that people who smoked for more than 40 years had up to a 50% raised risk of developing either colon or rectal cancer.

From Texas - Scientists have pinpointed a gene linked to medullobalstoma, according to a report published in the journal Science. Researchers genetically altered mice specifically to develop medulloblastoma--or, the deadliest form of brain cancer. However, they found that by shutting down the production of the gene Atoh1 they were able to prevent these mice from actually developing medulloblastoma, an aspect that researchers believe may lead to a new target in the fight against brain cancer.

And finally, back to Philadelphia - Long term exposure to secondhand smoke raises risk of breast cancer, according to another report published in the journal Cancer Epidemiology, Biomarkers & Prevention.  Researchers surveyed over 57,000 women who had no smoking history, but had experienced exposure to second hand smoke at home, work, or social settings. They found that women with high amounts of exposure to secondhand smoke during adulthood, primarily postmenopausal women, had an increased risk of breast cancer. Exposure under the age of 20, however, did not appear to raise this risk.