Study Indicates Low Socioeconomic Status, Not Race, Accounts For Cancer-Rate Differences In Blacks, Whites

BUFFALO, N.Y. -- The differences in cancer rates among blacks and whites in the United States are related more to low socioeconomic status rather than to race, a study conducted by researchers from the University at Buffalo shows.

Their analysis of 10 earlier studies found cancer rates were similar when whites and blacks with cancer were from the same socioeconomic level. Blacks, however, were four times more likely than whites to have disadvantaged or low socioeconomic status. Consequently, the amount of cancer attributable to this factor is four times greater in blacks than whites, according to the analysis, published in the Journal of the National Medical Association.

“Among blacks in the United States, perhaps as many as one in 10 cancer cases is related to low socioeconomic status,” said Kevin Gorey, Ph.D., a doctoral candidate in the UB Department of Social and Preventive Medicine when he conducted the study. “Taken by site, the statistics suggest that one in every three cases of stomach cancer and one of every seven cases of lung or cervical cancer are related to low socioeconomic status.”

Gorey noted: “The context in which people live can have an effect on health, above and beyond other factors. These results imply that solving the problem of severe economic impoverishment would go a long way toward diminishing cancer rates among both blacks and whites.”

Epidemiologic research has shown that cancer rates in general, and rates of some cancers in particular, are higher in black than in white populations. Statistics in this study point out that blacks have nearly 4 times the incidence of cancer of the esophagus, 2.3 times greater incidence of bone-marrow cancer, 2.3 times greater incidence of cervical cancer and almost twice the incidence of stomach cancer than whites.

Questions have remained, however, about the validity of basing these differences on racial factors. This review sought to define more clearly the role of socioeconomic status on cancer rates.

The researchers analyzed data from six national U.S. samples and four regional or statewide samples. Their analysis showed that rates for most cancers were similar for blacks and whites when subjects had the same socioeconomic status.

For example, both impoverished blacks and impoverished whites had about twice the risk of developing stomach cancer, and nearly 1 1/2 times the risk of developing lung cancer as blacks and whites of higher economic status.

The proportion of cancers attributable to the social aspects of a low economic strata differed greatly between races, however, Gorey said.

Cancers most closely linked to economic factors -- stomach, lung and cervix -- account for nearly half of the U.S. black-white cancer rate difference, he said.

“These data seem to strongly imply that any policy designed to bridge the socioeconomic gap between races also will serve to diminish the differences that exist between racial groups on cancer morbidity and mortality,” he said.

Co-author of the study is John E. Vena, Ph.D., UB associate professor of social and preventive medicine.