YOUR HEALTH
Sometimes, colon cancer is a family affair
DR. DONOHUE

DEAR DR. DONOHUE: Will you please write about Lynch syndrome?

My sister had gallbladder surgery, and during the operation the doctor found something he didn't like the looks of. It turned out to be a very large colon cancer. In 1980, I had colon cancer. Two of my other sisters have died of it. A doctor said we might have a gene of the Lynch syndrome. Anything you can tell us about this would be really appreciated. -- C.D.

ANSWER: Genes play a major role for some colon cancer patients. Your family's history is eye-opening, and a genetic impact jumps out at you. If one first-degree relative has or had colon cancer, the risk of it for other first-degree relatives is two to three times greater than is the risk for the rest of the population. A first-degree relative is a parent, a brother, a sister or a child. If two first-degree relatives have or had colon cancer, then the risk increases sixfold. Onequarter of colon cancers are influenced by family genes.

The above applies to the more or less ordinary genetic influences. There are two major kinds of highly genetically influenced colon cancer. One is familial adenomatous polyposis -- FAP. In this syndrome, thousands of polyplike growths sprout from the colon. If this were your family's condition, surgeons who took care of you and your sisters would have noted it.

The other highly genetically influenced colon cancer is HNPCC, hereditary nonpolyposis colorectal cancer, sometimes called the Lynch syndrome. Here, colon cancer is discovered earlier in life -- age 50 or younger -- than it is usually discovered. Colon cancer appears in two successive generations, and three close relatives have had it. Your family might fit its picture.

Discuss this with your doctor. Genetic tests can be done to prove the diagnosis. If the tests are positive, relatives ought to be tested so that colonoscopies can be performed at an early age, before any symptoms appear.

The booklet on colon cancer detection and treatment provides more information on this common cancer. Readers can obtain a copy by writing: Dr. Donohue -- No. 505, Box 536475, Orlando, FL32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6 Can. with the recipient's printed name and address. Please allow four weeks for delivery.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL32853-6475. Readers may also order health newsletters from www.rbmamall.com. 2006 North America Syndicate Inc. All Rights Reserved