Is there any evidence that fetal exposure to the drug DES may increase the risk of colon cancer/rectal cancer? My mother took DES during her pregnancy with me. Like many others, I have experienced gynecological problems as a result. Now, I am worried about whether it could affect my digestive tract too.

M.H.

Diethylstilbestrol (DES) was a hormonal drug used many years ago for preventing miscarriages and preterm labor. However, this drug proved not to be useful in these conditions. Even worse, daughters of women who used DES have experienced many reproductive problems, including very high rates of vaginal cancer. However, DES is not known to cause problems related to the digestive tract, such as colon cancer.

Interestingly, there is an inherited disorder, called Lynch syndrome, in which high rates of both gynecologic (uterus, ovary) and colon cancers run in families. Again, no link to DES or other drugs have been found in these cases.

While your DES exposure may not pose a risk of colon cancer, keep in mind that all people should be screened for colon cancer starting at age 50 (earlier if there is a family history of colon cancer). Also, there is a common misconception that colon cancer mainly affects men. This is not true: the disease strikes both sexes equally.