DEAR DOCTOR K:During a screening colonoscopy, my doctor found a polyp in my colon. Does this mean I have cancer?
DEAR READER:Colon polyps are common, non-cancerous growths of tissue inside the
colon, or large intestine. Some of them are benign. However, other colon
polyps can progress into colon cancer. These are called adenomatous
Overall, only a small percentage of adenomas progress to cancer, but
it’s not currently possible to accurately predict which ones will do so.
So generally they are removed.
Adenomatous polyps progress to cancer as the result of changes in
certain genes inside the cells of the polyp. Below is an illustration of
how a polyp can turn into cancer. Every human cell has certain genes
that, when turned on, can cause the cell to start multiplying
uncontrollably. Fortunately, those “oncogenes” are generally turned off.
Our cells also have certain tumor-suppressor genes that stop a cell
from multiplying uncontrollably. Also fortunately, those genes generally
are turned on.