Everyone has questions concerning cancer and Michael Sherman, medical director for Contra Costa Oncology, would like to answer yours. Contra Costa Oncology has offices in Walnut Creek, Concord, San Ramon and Rossmoor. If you have questions for Dr. Sherman, e-mail Donna Lynn Rhodes or Martha Ross, editor for Walnut Creek Patch, at martha@patch.com. 

Q:  How much cancer is hereditary and how much is environmental?
A: Medical science is still scratching the surface on this, but with new technologies and genetic testing, we are identifying more and more inherent cancers.  Determining and detecting environmental cancers from known toxic sources is difficult because environmental radiation can penetrate mutation-dividing cell forming growths that may become cancerous. Some inherited factors make these mutations more common, but inherited cancers are less common, affect younger individuals in general and multiple family members by definition. It's important to talk to your doctor about your family's cancer history and about any concerns you have.

Q:  What's all the controversy regarding mammograms?
A: Politics and medicine don't always mix. Simply put, there is a group of analysts who look at the cost-benefit ratio of certain screening tests used by a given population. For breast cancer, they took the frequency of that specific cancer, combined with the costs to assess it and then made their recommendations.  That task force was in the news recently because it recommended routine mammograms being performed every two years instead of annually. The American Society of Clinical Oncology hasn't agreed with these findings and encourages you to ask your doctor what is best for you.