Reemergence of Racial Disparity in Use of Adjuvant Chemotherapy in Stage III Colon Cancer
- Use of adjuvant chemotherapy increased among both white and black patients with stage III colon cancer from 1990–1991 to 2005.
- Use of adjuvant chemotherapy was less common in black patients in 2010.
In an analysis reported in the Journal of Clinical Oncology, Murphy et al found that disparity in the use of adjuvant chemotherapy in white vs black patients with stage III colon cancer may have recently reemerged after a trend of increasing use in both racial groups.
Changes in Use Over Time
The study involved data from 835 white patients and 384 black patients with stage III colon cancer randomly sampled from the Surveillance, Epidemiology, and End Results (SEER) program from the years 1990, 1991, 1995, 2000, 2005, and 2010.
Receipt of adjuvant chemotherapy among white vs black patients increased from 58% vs 45% in 1990–1991 to 72% vs 71% in 2005 and then decreased to 66% vs 57% in 2010. Overall, black patients were less likely to receive adjuvant chemotherapy (risk ratio [RR] = 0.82, 95% confidence interval [CI] = 0.72–0.93) after adjustment for age, comorbidity, insurance, and year of diagnosis. Among black patients, receipt of adjuvant chemotherapy did not differ across insurance categories (RRs = 0.80 for private insurance, 0.84 for Medicare, and 0.84 for Medicaid), but a larger proportion of black patients had Medicaid in all years of the study (overall 17.0% vs 4.8%).
The investigators concluded, “The chemotherapy differential narrowed after the time period of 1990 to 1991, but our findings suggest that the disparity reemerged in 2010. Recent decreases in chemotherapy use may be due, in part, to the economic downturn and an increase in Medicaid coverage.”
Caitlin C. Murphy, MPH, of the Gillings School of Public Health, the University of North Carolina at Chapel Hill, is the corresponding author of the Journal of Clinical Oncology article.
The study was supported by the National Institutes of Health and National Cancer Institute.