Brachytherapy Results Similar for Blacks, Whites

CHICAGO—Black men with localized prostate cancer do just as well as white men when treated with brachy-therapy alone, William Barrett, MD, said at the 88th Annual Scientific Assembly of the Radiological Society of North America (RSNA abstract 252RO-p).

Mortality from prostate cancer is more than two times higher for black men than it is for men from any other ethnic group. It has long been controversial whether this high mortality rate is because the disease is biologically more aggressive and therefore less curable in black men or because the diagnosis and treatment of prostate cancer are delayed in this patient population, said Dr. Barrett, assistant professor of radiation oncology and otolaryngology, Head and Neck Surgery, University of Cincinnati Hospital.

Several studies over the last few years have compared the outcomes of black and white American men treated with radical prostatectomy or external beam radiation therapy for prostate cancer, and those studies found that, stage for stage, the prognosis following surgery or radiotherapy was similar for the two ethnic groups, he said.

According to findings from a study conducted by Dr. Barrett, the same holds true for black and white men who were treated with radiation seed implantation. There was no difference in the number of recurrences after treatment or in the number of individuals who achieved and maintained nadir levels of prostate-specific antigen (PSA) that are indicative of disease-free status.

Dr. Barrett and his co-author William M. Kassing, PhD, compared outcomes among 173 men (12 black and 161 white) who were implanted with iodine 125 seeds for localized adenocarcinoma of the prostate between July 1995 and October 2001. Men in both groups had a similar stage of disease. The median Gleason score for each group was 6; median pretreatment PSA levels were 8.0 ng/mL and 6.0 ng/mL for black and white men, respectively. None of the patients had palpable extraprostatic disease at the time of treatment, and none received other hormonal therapy, surgery, or external beam radiotherapy for prostate cancer.

In 44 months of follow-up, none of the black men suffered a recurrence vs 5.6% of whites with 40 months of follow-up (P = .28). The percentage of men who achieved and maintained low PSA levels was similar in both groups: 83% of blacks and 85% of whites had a PSA of 1.0 ng/mL or less (P = .43); 67% of blacks and 72% of whites had PSA of 0.5 ng/mL or less, (P = .34); and 50% of blacks and 44% of whites had PSA of 0.2 ng/mL or less (P = .35).

"We found no difference in outcome between African-Americans and Caucasians by each of those definitions of disease freedom," Dr. Barrett said. He added that the findings have implications for the debate over the value of PSA screening, which may detect slow-growing disease that will never be an issue for the patient.

"Our findings underscore the need for more screening among African-American males so the cancer is detected early," he said. "Because prostate cancer in African Americans is generally not slow-growing, the combination of early diagnosis and effective treatment should be particularly beneficial."