Differences in Treatment and Outcome Between African-American and White Women with Endometrial Cancer
Abstract & Commentary
Synopsis: African-American women with endometrial cancer are significantly less likely to undergo primary surgery and have significantly shorter survival than white women with endometrial cancer.
Source: Randall RC, Armstrong KJ. Clin Oncol. 2003; 21:4200-4206.
Randall and Armstrong recently reported an interesting study in which they analyzed 1992-1998 Surveillance, Epidemiology, and End Results (SEER) data for 21,561 women with epithelial cancers of the endometrium with the objective of investigating disparities in treatment and outcomes between African-American and white women with endometrial cancer. Sequential Cox proportional hazard models were used to determine the association between tumor characteristics (stage, grade, and histologic type), sociodemographic characteristics (age and marital status), and treatment (surgery and radiation therapy) and racial difference in mortality. The unadjusted hazard ratio (HR) for death from endometrial cancer for African-American women compared with white women was 2.57.
However, African-American women were significantly more likely to present with advanced-stage disease and have poorly differentiated tumors or tumors with an unfavorable histologic type and were significantly less likely to undergo definitive surgery at all stages of disease. Adjusting for tumor and sociodemographic characteristics lowered the HR for African-American women to 1.80. Further adjustment for the use of surgery reduced the HR to 1.51. The association between surgery and survival was stronger among white women (HR, 0.26) than among African-American women (HR, 0.44). Randall and Armstrong concluded that African-American women with endometrial cancer are significantly less likely to undergo primary surgery and have significantly shorter survival than white women with endometrial cancer. They further noted that racial differences in treatment are associated with racial differences in survival and that the association between use of surgery and survival is weaker among African-American than white women, raising the question about potential racial differences in the effectiveness of surgery.
Comment by David M. Gershenson, MD
Approximately 40,000 American women are diagnosed with endometrial cancer in the United States annually. Based on SEER data, the survival rate for African-American women with endometrial cancer was approximately 59%, compared with 86% for white women. As noted in this study, prior studies revealed that African-American women have a higher incidence of poorly differentiated tumors or tumors with unfavorable histologies. In addition, most studies indicated that, even after controlling for comorbid conditions and socioeconomic status, these differences persist. The present study focused on the relationship between treatment and survival. Randall and Armstrong found that, at all stages, African-American women were less likely to receive definitive surgery. They also point out, however, this relationship may not be causal. By the very act of performing surgery, which may reclassify apparent early stage patients with more advanced disease into a higher stage category, survival is improved.
The reasons for a lower rate of surgery in African-Americans remain somewhat elusive. Partial explanations include differences in extent of disease, access to care, or comorbid conditions. One of the problems with any study using the SEER database is that information is limited. For instance, the SEER database does not include much of the sociodemographic data or comorbidity data that would potentially provide insights into some unresolved issues. As with several other diseases and conditions, further studies will be necessary to elucidate the reasons for differences in outcome between racial/ethnic groups. Fortunately, health disparities research is of growing interest and is increasingly being funded.
Dr. Gershenson is Professor and Chairman, Department of Gynecology, M.D. Anderson Cancer Center, Houston, Tex.