The possible role of genetics in racial disparities in cancer outcomes is highlighted again with the finding that Blacks have twice the risk for recurrent cancer of the head and neck as White Americans who receive similar treatment for apparently similar tumors, according to an article in the December 1st issue of Cancer.

In the United States, about 37,000 people are diagnosed annually with a cancer of the head and neck, accounting for roughly 3 percent of all cancer cases. The disease is most common in people who use tobacco or are heavy drinkers, but it can occur in individuals who have no such risk factors.

"The cure rates are fairly high if you catch it early, so early diagnosis is important," said William M. Mendenhall, M.D., lead author of the study. "Another issue is quality of life because of the location of the cancer itself and the treatment of the cancer. If you don't control this type of cancer it is typically associated with significant detrimental effects on quality of life: It affects your ability to eat, to communicate, to go out in public. It's not a real common cancer, but it has a major impact on the people who wind up getting it."

When the current study started, the researchers did not expect to see any differences in long-term survival based on race because the nearly 700 patients whose medical records were analyzed all had tumors that were of similar size and aggressiveness. In addition, all patients received identical treatment: twice-daily radiation therapy for 6.5 weeks, with surgery when needed. About 8 percent of the patients were black.

With follow-up periods of up to seven years, researchers did find a racial difference: Cancer was significantly more likely to recur in Black patients, usually as distant metastasis.

Mendenhall said, "I really didn't think that if you looked at patients with similar
stage tumors who were treated the same way that there would be a difference in outcome. But all received the exact same treatment and we accounted for confounding variables, like perhaps minority patients might be of lower socioeconomic status and therefore have less access to health care or be less likely to complete treatment or even get the treatment considered to be optimal. I fully expected to see no difference in outcomes. Lo and behold, when we looked there turned out to be a difference. It's not really clear exactly why."

He added, "The reason it's important is it tells us we need to do something to modify treatment for those patients to try to reduce their risk of having distant metastasis because if you develop a distant metastasis, the odds are almost 100 percent you're going to die from the cancer. So it's important to try to reduce that risk."

One limitation to the study was the inability to fully evaluate risk factors such as use of tobacco or alcohol, which might have an impact on tumor aggressiveness that is not apparent in baseline differences in stage or histologic appearance.
The authors stress that the findings call attention to the importance of evaluating ethnic and racial influences on disease and prognosis as one more step to individualizing risk profiles at time of diagnosis and determining optimal first-line treatments.