In African-American men with favorable-risk prostate cancer, the use of androgen deprivation therapy (ADT) may shorten survival, according to researchers at Brigham and Women’s Hospital, Boston, MA, who published their findings online on August 4, 2016, in Cancer. In light of their results, they concluded that ADT should be reserved for the treatment of men with higher risk prostate cancer.
"When African-American men were exposed to an average of only 4 months of hormone therapy, primarily used to make the prostate small enough for brachytherapy, they suffered from higher mortality rates due to causes other than prostate cancer than non-African American men," said lead author Konstantin Kovtun, MD, a resident at Brigham and Women’s Hospital.
"This leads us to believe that there may be something intrinsic to the biology of African-American men that predisposes them to this increased risk of death and that this deserves further study," he added.
Compared to non-African-American men, African-American men are more likely to have comorbid illnesses that may interact with ADT to possibly reduce survival. These researchers, therefore, conducted this study to determine the impact of race on the risk of all-cause mortality (ACM) and other-cause mortality (OCM) in men undergoing treatment for favorable-risk prostate cancer.
They included 7,252 men with low- or favorable intermediate-risk prostate cancer who had been treated with brachytherapy and neoadjuvant ADT (n=1,501) or without neoadjuvant ADT (n=5,751) for a median of 4 months between 1997 and 2013. In all, 869 men died (12.0%) after a median follow-up of 8.04 years—48 (5.52%) from prostate cancer and 821 (94.48%) from other causes.
In men who had received ADT, Kovtun et al. found a significant association between African-American race and increased risk of ACM (adjusted hazard ratio [AJR]: 1.77; 95% CI, 1.06-2.94; P=0.028), as well as increased risk of OCM (AHR: 1.86; 95% CI, 1.08-3.19; P=0.024). These increased risks were not seen in men who did not undergo ADT (AHR [ACM]: 1.33; 95% CI, 0.93-1.91; P=0.12; AHR [OCM]: 1.3; 95% CI, 0.96-2.02; P=0.08).
"These results show that careful consideration should be taken by physicians when recommending treatment for low- or favorable-intermediate prostate cancer, a cancer that very few men die of even without treatment," said senior author Anthony D'Amico, MD, PhD, Chief of Genitourinary Radiation Oncology at Brigham and Women’s Hospital.
"There is no evidence that ADT followed by brachytherapy increases the chance of cure in comparison to other treatments, such an external beam radiation therapy alone, in these men with favorable risk prostate cancer. The subsequent risks of ADT, specifically linked to African-American men, deserve further study," Dr. D’Amico concluded.