Colon Cancer in the Younger Patient

By Andrew D. Bailey, M.D.

Cancer in the young and fit reminds us that although diet and life-style changes can improve our chances of living cancer-free, we cannot always prevent the disease. Until we develop effective chemoprophylaxis (medications that prevent cancer) and more effective chemotherapy, early detection and surgery will be our best means of preventing cancer deaths.

The claim that we can completely eradicate colon cancer with our current guidelines and technology is exaggerated. Guidelines for the prevention and early detection of colon cancer advise patients to undergo a screening colonoscopy at or around the age of 50. That would protect most of the age group from dying of the disease. What about the younger patients? They make up the minority of colon cancer patients, to be sure, but the disease is no less lethal in that population. Do we have screening strategies for them, too?

Many instances of colon cancer in younger patients are sporadic, arising seemingly out of nowhere without rhyme or reason. However, the younger the patient is, the more likely that he or she inherited the tendency to get the disease. The most common of the inherited tendencies is hereditary nonpolyposis colon cancer (HNPCC); an older term is the Lynch Syndrome.

HNPCC may be more common than appreciated; perhaps as many as five percent of colon cancer patients have this trait. People who inherit this are not only more likely to develop colon cancer, but do so at a much younger age. Even 20-year-olds with the HNPCC trait have been known to develop cancer.

The diagnosis of cancer can be more difficult to make in these patients. Most of the cancers are too far up in the colon to be seen with office procedures such as sigmoidoscopy. The cancers tend to be flatter and more difficult to spot with full colonoscopy. CT colography ("virtual colonoscopy") does not have the resolution to pick up many of these lesions at an early stage.

We have different screening guidelines for family members of patients with suspected HNPCC. For them a colonoscopy should begin at the age of 25, or ten years less than the youngest family member ever diagnosed with colon cancer. At age 40, colonoscopy should be performed annually.

When should HNPCC be suspected? A patient who is diagnosed with colon cancer under the age of 40 should consider genetic testing; even patients who get diagnosed under 50 should urge their siblings to be screened no later than their 40 th birthday. By the time three family members are diagnosed, with one of them being in a different generation, HNPCC is probable and genetic testing should be performed. Families in which everyone seems to develop cancer of any kind should also raise suspicions of a genetic syndrome.

Genetic testing is commercially available and will detect 90 percent of the mutations that cause HNPCC. The first family member must be tested for all the mutations, but once one has been found, all other members need only be tested for the one particular abnormality. If subsequent family members test negative for that one mutation, they need not undergo screening differently from the rest of the population.

As serious as colon cancer is, the younger patient who carries this diagnosis can impart a wonderful gift to his or her family by urging them all to undergo proper screening. Working with their doctors, they can help to reduce the risk of colon cancer death among the ones they hold so dear, regardless of their age.

Andrew Bailey, M.D., is a graduate of Davidson College and Vanderbilt University School of Medicine. He did his postgraduate training at Brooke Army Medical Center in San Antonio , Texas and is board-certified in both Internal Medicine and Gastroenterology. He has practiced in Louisville since 1990.