Disadvantaged Americans are far more likely to die of the most treatable form of lung cancer--not because of their health habits, but because they don't receive the proper treatment.
A University of Southern California expert on health-care delivery has analyzed more than 5,000 cases of stage I non-small-cell lung cancer in an attempt to explain why mortality is higher among racial minorities and the socially disadvantaged than among higher-income Americans and whites.
Howard P. Greenwald, PhD, found that surgery may have saved the lives of nearly one in three patients whose cancer was detected early enough. But the poorest patients were about a third less likely to undergo surgery than the richest patients. Half (50%) of the patients in the bottom 10% of income levels received surgical treatment, as compared with nearly three-quarters (72%) of patients in the top 10% of income levels.
Differences in mortality were even more dramatic: Only 22% of the poorest survived for at least 5 years after diagnosis, whereas 45% of the richest patients survived for that length of time.
As a subset of the study group, African-American patients fared even worse. At all economic levels, they had only a one in four chance of surviving, compared to a one in three chance among white Americans. Whereas 61% of white Americans underwent surgery, only 51% of African-Americans received that treatment.
Dr. Greenwald presented his findings at an American Cancer Society conference in New Orleans. "In the form of lung cancer studied, lack of appropriate care seems to have contributed strongly to excess mortality among the disadvantaged" he said. "It explains about 50% of the excess mortality in poor people and all of the excess mortality in African-Americans."
Conventional wisdom has held that the disadvantaged are more likely to die of cancer because of health habits. Studies have consistently found that they are less likely to exercise or eat healthy diets and more likely to smoke cigarettes than the affluent. Discrepancies in survival rates between African-American and white patients have been attributed to income differences.
"In the past, we've blamed the victims, but now it looks like the problem may be that we have not been giving them adequate treatment," Dr. Greenwald asserted. He contended that differences in educational levels and access to health care might help explain the discrepancies in surgery rates between rich and poor patients. "The reasons for the race-based discrepancies are more subtle and bear further research, he said. "They may have to do with communication problems, suspicion, mistreatment or reluctance to use a system where only about 3% of physicians are African-Americans."
Further study is needed to determine the impact of income and of race on mortality from other cancers, Dr. Greenwald cautioned. However, he does not believe his findings will be isolated to non-small-cell lung cancer. "I would expect the findings to be repeated in about 50% of cases, because that's the proportion of cancers that are treatable when detected at early stages," he said. "These findings should wave a red flag."
Dr. Greenwald looked specifically at non-small-cell cancer because it is treated only with surgery, making the effects of medical intervention easier to track than with some other cancers. Moreover, survival rates are high when surgical treatment is administered in this cancer's earliest stage.
Dr. Greenwald studied 5,189 cases of non-small-cell lung cancer diagnosed between 1978 and 1982 and documented by the National Cancer Institute's Cancer Surveillance System. He ranked the cases according to patients' economic levels. For each of 10 economic levels, he then analyzed the death rates and the treatment that patients received. In addition, he identified 855 African-Americans in the study group and separately analyzed their mortality and treatment.
Dr. Greenwald, who is Professor of Public Administration at the USC School of Public Administration's Sacramento Center, has written extensively about socioeconomic factors and cancer. His current and recent sources of funding include the US Department of Health and Human Services, American Cancer Society, California Tobacco-Related Disease Research Program, and W.K. Kellogg Foundation.