Increased Risk for Ovarian CA w/ Family History of Colon Cancer

My father has colon cancer does this mean that I am a candidate for the same disease?  Also, I've heard that this increases my chances for ovarian cancer - is that true?

Thanks so much for this wonderful forum!!

Carol A

[Annekathryn Goodman, M.D.]

Dear Carol,
Here are the statistics on colon cancer. Approximately 145,290 new cases of large bowel cancer are diagnosed each year in the United States, of which 104,950 are colon and the remainder rectal cancers. In 2005, more than 56,000 Americans died of CRC (colo-rectal cancer), accounting for approximately 10 percent of all cancer deaths. In the United States, CRC ranks second to lung cancer as a cause of cancer death, and it is third both in frequency and cause of cancer death. (From Cancer Statistics 2005).

Colon cancer, as is true for many other cancers, can be sporadic or genetic. Most cancers are sporadic and the risk of developing cancers increases as we age. (We just do not repair ourselves as well as we get older.)

There are two major genetic syndromes associated with colon cancers:
Hereditary non-polyposis colon cancer (HNPCC) accounts for about 5 percent of colorectal cancers and an increased risk of other cancers (Endometrial is the most common, Ovary, stomach, small bowel, hepatobiliary system, renal pelvis or ureter, and possibly prostate cancers can also be seen). Familial adenomatous polyposis (FAP) accounts for about 1 percent of colorectal cancers, and cancers are preceded by hundreds of polyps throughout the colon.

If your father is the only family member to develop colon cancer, you are not necessarily at any increased risk for ovarian cancer. If you have multiple family members with colon, breast, endometrial, ovarian cancers, it would be important to consider meeting with a genetic counselor to review your risks and look at possible genetic testing. Most major cancer centers have a genetic counselor on staff.

This is not a forum for colon cancer but I cannot resist making a plea to all folks to insist that their healthcare practitioners include a rectal examination and stool test for blood as part of their annual examination. They should also get screening colonoscopies starting at 50 years if no family history and at age 40 if there is a family history (that would be you, Carol.)