Nowadays one hears the term “disparities” described and lamented upon frequently in the comparison of outcomes between racial or ethnic groups for various diseases, including, as we are concerned, for various cancers. The reality is that there are indeed disparities in mortality between those of African descent and whites for virtually every cancer across the board—extensive studies suggest that these reflect differences in access to care and thus the outcomes are worse for almost everything, reflecting later diagnosis, poorer stage distributions, worse treatment, lower quality physicians and hospitals. Interestingly these disparities tend to be less pronounced or minimized for tumors for which treatment is less effective, like pancreatic cancer, where treatment has only marginal benefits and thus the quality of care has less pronounced effects.
Biological differences between the races also play some role but only for a small number of cancers. Prostate cancer is twice as common in those of African descent as whites, almost surely on some genetic basis, though the genes have not been identified. This is true for those of African descent in the U.S., as well as those native to Africa, those in Jamaica or in other Caribbean islands—it makes no difference where the individual is—if he is of African descent, he has an increased risk of prostate cancer.
Multiple myeloma is another malignancy that is also increased in blacks as compared to whites, and apparently also on a genetic basis. Endometrial (uterine) cancer is also more common in those of African descent, but this may reflect biological/hormonal factors, such as body mass index or hormonal reproductive factors.
The racial disparity that has been most studied is the increased mortality of blacks with breast cancer, as whites have an increased incidence of breast cancer as compared to blacks, and the increased mortality is present even in populations where there is equal access to care, such as within the VA health care system, or for members of Kaiser Permanente in California, a health maintenance organization. Even within these insurance systems, black women with breast cancer, stage for stage, have worse mortality—this remains a puzzle unexplained by biological characteristics or differences between their tumors.
Early studies of disparities generally understood access to care as a major issue. An emphasis was placed on differences in lifestyle and screening and stage distribution. Thus, great efforts were made to try to equalize breast and cervical, and later colon screening, rates between those populations. To a great degree, great progress has been made both locally in NYC in achieving, for example, similar breast cancer stage distributions, as well as nationally. Efforts were made in this regard going back to the 1970s and 1980s.
Peter Bach was born in 1966, went to Harvard College and then the University of Minnesota for medical school, before doing his residency at Johns Hopkins, where he specialized in pulmonology. He received a master’s degree in health policy from the University of Chicago and joined the faculty at Memorial Sloan-Kettering where he studied health economics and drug policy. A paper by Bach published in the New England Journal of Medicine in 1999 effectively began the modern era of the study of racial disparities and was a milestone.
This study used the Surveillance Epidemiology and End-Results (SEER) database, which covers about 14% of the U.S. population and registers all cancer patients in that region. These patients were linked to Medicare for the period 1985-1993 so that one could ascertain what tests or procedures were done on each one of these cancer patients. In theory, those with non-small cell lung cancer that was stage I or stage II have the opportunity to undergo surgical resection of their tumors with potentially very good cure rates. What Bach and his colleagues found for this Medicare-aged population (65 years or older) was that the rate of surgery for stage I-II lung cancer was 12.7% lower for black than for white patients (64.0% versus 76.7%, p>0.001). In addition, he found that the survival rate for those undergoing surgery was equivalent for both racial groups. Furthermore, the survival rate for those not undergoing surgery was the same for both racial groups.
This paper was the first to so clearly illustrate the impact of access to care and its effects on survival and outcomes in cancer care. It had a profound effect at the time of its publication and led to a plethora of similar studies for other treatments and interventions for other malignancies. It has certainly led to a major effort to try to keep such disparities to a minimum in subsequent medical practices.
Alfred I. Neugut, MD, PhD, is a medical oncologist and cancer epidemiologist at Columbia University Irving Medical Center/New York Presbyterian and Mailman School of Public Health in New York.
This article is for educational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment, and does not constitute medical or other professional advice. Always seek the advice of your qualified health provider with any questions you may have regarding a medical condition or treatment.
