Racial disparities in recurrence among patients with early-stage endometrial cancer: is recurrence increased in black patients who receive estrogen replacement therapy?

Abstract

Background: Population-based studies suggest that, because of inequalities in treatment, black women with localized endometrial cancer have shorter survival compared with white women. The objective of the current investigation was to determine whether there is a racial disparity in outcome between black patients and white patients with early-stage endometrial cancer treated similarly in a clinical trial setting.

Methods: A retrospective review of 110 black patients and 1,049 white patients with stage I and II endometrial cancer (graded according to the International Federation of Gynecology and Obstetrics grading system) was performed using data from a randomized, placebo-controlled trial performed by the Gynecologic Oncology Group that evaluated postoperative estrogen replacement therapy (ERT) and the risk of cancer recurrence. Demographic, pathologic, treatment, and outcome-related data were collected and analyzed using regression and survival analysis.

Results: Estimates of recurrence-free survival suggested that black patients may be more likely to have disease recurrence, particularly those receiving ERT. Within a median follow-up of 3 years, 5 of 56 black patients with endometrial cancer in the ERT group were identified with recurrent disease compared with only 8 of 521 white patients. Adjusted for age, body mass index, and tumor grade, the relative risk of recurrence among blacks in the ERT group was 11.2 (95% confidence interval, 2.86-43.59; P = .0005).

Conclusions: The findings of the current study suggested that recurrence-free survival may be shorter among black women with stage I endometrial cancer, even in a clinical trials setting in which patients receive similar treatment and follow-up. This increased risk of recurrence appeared to be most evident in black women with endometrial cancer who maintained ERT after primary treatment.

Figure 1

Figure 1a: Kaplan-Meier Estimate of Recurrence-free Survival (RFS) for Patients Randomized to ERT Group by Race Figure 1b: Kaplan-Meier Estimate of Recurrence-free Survival (RFS) for Patients Randomized to Placebo Group by Race

Figure 1

Figure 1a: Kaplan-Meier Estimate of Recurrence-free Survival (RFS) for Patients Randomized to ERT Group by Race Figure 1b: Kaplan-Meier Estimate of Recurrence-free Survival (RFS) for Patients Randomized to Placebo Group by Race

Figure 2

Figure 2a: Kaplan-Meier Estimate of Recurrence-free Survival (RFS) for Black Patients by Treatment Figure 2b: Kaplan-Meier Estimate of Recurrence-free Survival (RFS) for White Patients by Treatment

Figure 2

Figure 2a: Kaplan-Meier Estimate of Recurrence-free Survival (RFS) for Black Patients by Treatment Figure 2b: Kaplan-Meier Estimate of Recurrence-free Survival (RFS) for White Patients by Treatment