Adjuvant androgen deprivation therapy (ADT) combined with radiation therapy for favorable-risk prostate cancer (PCa) is associated with an increased risk of death in black men compared with white men, a new study suggests.
The study included 7252 men underwent brachytherapy with or without neoadjuvant ADT for low-risk or favorable intermediate-risk PCa. Men received ADT to reduce prostate size and facilitate brachytherapy, and not for therapeutic gain. Among those who received ADT, black men had a significant 77% increased risk of all-cause mortality and significant 86% increased risk of death from causes other than PCa in multivariable analysis, a team led by Konstantin A. Kovtun, MD, of Brigham and Women's Hospital-Dana-Farber Cancer Institute in Boston, reported online ahead of print in Cancer. The investigators found no significant difference in PCa-specific mortality. Dr. Kovtun and his colleagues observed no significant differences in mortality risks among patients who did not received ADT
The investigators concluded that the use of ADT in black men should be reserved for treating higher-risk PCa, for which level 1 evidence supports its use.
ADT is not recommended as part of the management of low-risk or favorable intermediate-risk PCa, so these findings should raise awareness about the potential negative impact on survival for black men, according to the investigators.
The study population consisted of 533 black and 6719 non-black patients with median ages of 65.3 and 68.3 years, respectively. One-fifth of the black and non-black groups received ADT for a median follow-up of 4 months. After a median follow-up of 8 years, 869 men (12%) died, including 48 (5.5%) from PCa and 821 (94.5%) from other causes. The median follow-up for men who received ADT was 6.1 years for blacks and 9.6 years for non-blacks.
Dr Kovtun's team said it is notable that the median follow-up for black men received ADT was significantly shorter by 3.5 years compared with non-black men. Therefore, they stated, black men receiving ADT had a significantly increased risk of all-cause and other-cause mortality despite having less time to experience mortality events.
Black patients had a significantly greater proportion of individuals with cardiometabolic comorbidities than non-black patients (27.8% vs 23%). The researchers pointed out that they adjusted for cardiometabolic comorbidities in their multivariable analysis, so these comorbidities alone do not appear to be sufficient to explain the significant increase in the risk of all-cause and other-cause mortality.
The authors cautioned that their observations are derived from a retrospective analysis and, therefore, are hypothesis-generating and require prospective validation.