ACCENT: Blacks had poorer OS, recurrence-free survival than whites after chemotherapy for colon cancer

Yothers G. J Natl Cancer Inst. 2011;doi:10.1093/jnci/djr310.

Issue: November 10, 2011

Black patients with resected stage II and stage III colon cancer survived at lower rates compared with whites despite similar treatment, according to results of a meta-analysis of more than 14,000 patients.

Researchers concluded that the differences in survival could be due to factors unrelated to the patients' treatment for adjuvant colon cancer.

To explore the causes of the disparity, researchers examined survival data from the Adjuvant Colon Cancer Endpoint (ACCENT) collaborative group database. Researchers reviewed data on 14,611 patients enrolled in 12 phase 3 clinical trials conducted in North America from 1977 to 2002; 8.3% of patients in those trials were black. All patients underwent standardized adjuvant treatment after resection of the primary tumor.

Black participants were more likely to be younger (58 years vs. 61 years) and female (55% vs. 45%).

OS for black patients was worse than in whites (HR=1.22; 95% CI, 1.11-1.34). The 5-year OS estimate for blacks was 68.2% vs. 72.8% for whites.

Recurrence-free survival was similarly inferior for black patients (HR=1.14; 95% CI, 1.04-1.24). The adjusted 3-year recurrence-free survival was 68.4% for blacks and 72.1% for whites.

However, recurrence-free interval did not differ significantly by race, and estimated 3-year recurrence-free interval rate was 71.3% for black patients vs. 74.2% for white patients.

In an accompanying editorial, Olufunmilayo I. Olopade, MD, director of the Center for Clinical Cancer Genetics and Global Health at the University of Chicago, and colleagues said these results uphold what oncologists treating colorectal cancer have known for a decade: Black patients have poorer OS compared with white patients, even when both groups receive identical treatment.

"If trials are going to continue to be used to examine racial differences in cancer outcomes, then we cannot continue to perform them as post hoc unplanned subset analyses; otherwise, the field will not advance," Olopade and colleagues wrote. "At a bare minimum, basic sociodemographic and detailed comorbidity information should be prospectively collected and integrated with detailed tumor and host biology data.

"We have documented racial and ethnic differences in cancer survival by looking from 10,000 feet over the past decade, but it is past time for us to get out of the clouds and collect and integrate data that advance the field," they wrote.

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