Association Between African American Race and Clinical Outcomes in Men Treated for Low-Risk Prostate Cancer With Active Surveillance

Abstract

Importance: There is concern that African American men with low-risk prostate cancer may harbor more aggressive disease than non-Hispanic White men. Therefore, it is unclear whether active surveillance is a safe option for African American men.

Objective: To compare clinical outcomes of African American and non-Hispanic White men with low-risk prostate cancer managed with active surveillance.

Design, setting, and participants: Retrospective cohort study in the US Veterans Health Administration Health Care System of African American and non-Hispanic White men diagnosed with low-risk prostate cancer between January 1, 2001, and December 31, 2015, and managed with active surveillance. The date of final follow-up was March 31, 2020.

Exposures: Active surveillance was defined as no definitive treatment within the first year of diagnosis and at least 1 additional surveillance biopsy.

Main outcomes and measures: Progression to at least intermediate-risk, definitive treatment, metastasis, prostate cancer-specific mortality, and all-cause mortality.

Results: The cohort included 8726 men, including 2280 African American men (26.1%) (median age, 63.2 years) and 6446 non-Hispanic White men (73.9%) (median age, 65.5 years), and the median follow-up was 7.6 years (interquartile range, 5.7-9.9; range, 0.2-19.2). Among African American men and non-Hispanic White men, respectively, the 10-year cumulative incidence of disease progression was 59.9% vs 48.3% (difference, 11.6% [95% CI, 9.2% to 13.9%); P < .001); of receipt of definitive treatment, 54.8% vs 41.4% (difference, 13.4% [95% CI, 11.0% to 15.7%]; P < .001); of metastasis, 1.5% vs 1.4% (difference, 0.1% [95% CI, -0.4% to 0.6%]; P = .49); of prostate cancer-specific mortality, 1.1% vs 1.0% (difference, 0.1% [95% CI, -0.4% to 0.6%]; P = .82); and of all-cause mortality, 22.4% vs 23.5% (difference, 1.1% [95% CI, -0.9% to 3.1%]; P = 0.09).

Conclusions and relevance: In this retrospective cohort study of men with low-risk prostate cancer followed up for a median of 7.6 years, African American men, compared with non-Hispanic White men, had a statistically significant increased 10-year cumulative incidence of disease progression and definitive treatment, but not metastasis or prostate cancer-specific mortality. Longer-term follow-up is needed to better assess the mortality risk.

Figure 1.. Active Surveillance Cohort Flow Chart

Figure 2.. Cumulative Incidences of Selected Outcomes

A, The median years of follow-up were 5.82 (interquartile range [IQR], 3.66-8.47) for African American men and 6.50 (IQR, 4.22-9.08) for non-Hispanic White men (Wilcoxon P < .001). B, The median years of follow-up were 5.37 (IQR, 2.85-7.32) for African American men and 6.02 (IQR, 3.48-8.62) for non-Hispanic White men (Wilcoxon P < .001). C, The median years of follow-up were 7.45 (IQR, 5.66-9.58) for African American men and 7.62 (IQR, 5.67-9.91) for non-Hispanic White men (Wilcoxon P = .11). D, The median years of follow-up were 7.48 (IQR, 5.67-9.62) for African American men and 7.62 (IQR, 5.69-9.95) for non-Hispanic White men (Wilcoxon P = .14). E, The median years of follow-up were 7.48 (IQR, 5.67-9.62) for African American men and 7.62 (IQR, 5.69-9.95) for non-Hispanic White men (Wilcoxon P = .12).