I’m not asking for a general average, just the odds that would apply to my particular situation. I’m a 47 year old male, about 5′ 4.5″, about 177 lb. (overweight, I should probably weigh about 135). I don’t smoke and never smoked, and have had fairly minimal exposure to secondhand smoke since my parents didn’t smoke. I only drink rarely now, but drank more in college and in my 20′s and to some extent in my 30′s – going out drinking maybe once a week in college, then once every few weeks to once a month as I got older. For the past 6 years, I have just had an occasional beer or two or glass of wine maybe once or twice a month. Other than some extremely minor problems, my only real health problems are high cholesterol and acid reflux, both of which are controlled by medication.

I have no family history of colon cancer and know of no relatives that ever had it. My father died of pancreatic cancer and my mother died of breast cancer, and I mentioned this to the doctor because I thought that the gene that may have contributed to my parents’ cancers (I don’t really know if there was a genetic component, though), may also be linked to colon cancer. The doctor said that my parents’ cancers weren’t genetically linked to colon cancer, but I don’t really believe him.

I would like only numerical answers, such as 1 in X or X%. I will ask the doctor what he thinks before I get the colonoscopy. If he gives me an answer, the closest one to his answer wins. If he doesn’t give me a straight answer, I will decide who wins based on reliable scientific references, so if you give me a source for how you calculated my odds that might help.

The outcome of the actual colonoscopy is irrelevant in determining the winner, so please don’t answer with 0% or 100%.