Active Surveillance for Prostate Cancer Is Risky for Blacks

Counseling Advised

Nick Mulcahy

July 02, 2013

The calculated gamble of using active surveillance to manage very-low-risk prostate cancer appears to be more dicey for black men, according to a new study.

That's because black men with very-low-risk disease are more likely than their white counterparts to actually have more aggressive disease that goes undetected with current diagnostic approaches, the study authors report.

They retrospectively looked at 256 black and 1473 white very-low-risk patients who nonetheless underwent radical prostatectomy at Johns Hopkins University in Baltimore, Maryland.

It is the largest cohort to date of black men who qualify for active surveillance, according to senior author Edward Schaeffer, MD, and colleagues from Hopkins.

They found that the black men had significantly higher rates of upgrading at surgery than their white counterparts (27.3% vs 14.4%; P < .001), and more adverse pathology (i.e., high-risk disease) (14.1% vs 7.7%; P = .001).

"African American men with very-low-risk prostate cancer should be counseled about increased oncologic risk when deciding among their disease management options," write Dr. Schaeffer and his coauthors.

The study was published online June 17 in the Journal of Clinical Oncology.

In a press statement, Dr. Schaeffer discouraged the conventional use of active surveillance in black men: "This study offers the most conclusive evidence to date that broad application of active surveillance recommendations may not be suitable for African Americans."

Nonetheless, the authors believe that active surveillance is a valuable management strategy. "Oncologic outcomes for men in active surveillance cohorts are favorable," they state. However, they note that the studies that establish the benefits and risks of active surveillance are largely based on white men.

Race-specific criteria for entry into active surveillance are needed, the authors conclude.

The study is a lesson not just for black men and their clinicians, said Willie Underwood III, MD, from Roswell Park Cancer Institute in Buffalo, New York, who was not involved in the study.

"No matter what, men at very low risk aren't necessarily so. While blacks were more likely to have higher-risk disease at surgery, whites were not at zero risk," he told Medscape Medical News.

He explained that for every 100 black men with a very-low-risk profile in the study, there were about 25 who actually had higher-risk disease. And for every 100 such white men, there were about 15 who actually had higher-risk disease.

"The methods we are using to classify men into risk strata — PSA and biopsy — are not enough," he said. "We need more tools."

These findings have nothing to do racial disparities in access to care, added Dr. Underwood. "They reflect disparities in outcomes."

More Study Details

The men in the study were culled from a group of 19,142 men who underwent radical prostatectomy at The Johns Hopkins Hospital from 1992 and 2012.

The 1801 men selected for study inclusion had very-low-risk disease, according to National Comprehensive Cancer Network criteria. They had a clinical-stage disease of T1c or less, a biopsy Gleason score of 6 or less, no more than 2 positive biopsy cores, core involvement of 50% or less, a prostate-specific antigen (PSA) level below 10 ng/mL, and a PSA density of 0.15 ng/mL per cm³ or less.

A man was determined to have an adverse pathologic finding at surgery if his clinical disease stage was pT2 and his Gleason score was at least 4+3; if his disease stage was pT3a, his Gleason score was 3+3, and he had positive surgical margins; if his disease stage was pT3a and his Gleason score was at least 3+4; or if his clinical disease stage was at least pT3b.

The characteristics of the white and black men in the study were similar; however, the black men had "slightly worse" Charlson comorbidity scores, the authors report. The median age was 58 years, which is younger than other active surveillance cohorts.

After surgery, black men had a lower rate of organ-confined cancers than white men (87.9% vs 91.0%; P = .004), a higher hazard of biochemical recurrence (4.0% vs 1.4%; log-rank P = .004), and higher pathologic risk scores, measured with the Cancer of the Prostate Risk Assessment Post-Surgical scoring system (14.8% vs 6.9%; P < .001).

After a median follow-up of 3 years (2 years for black men and 4 years for white men), there were no differences in metastasis-free, cancer-specific, or overall survival.

In previous studies of men managed with active surveillance, results for cancer-related outcome by race have been mixed, the authors point out. In one study of men with low-risk disease, the black men fared no worse than the white men (Urology. 2009;73620-623). In another study, being black was an independent predictor of disease progression in men with very-low-risk disease (J Urol. 2012;187:1594-1599). Both these studies, however, were small, with fewer than 60 patients, Dr. Schaeffer and colleagues note.

The study was supported by National Institute of Diabetes and Digestive and Kidney Diseases, the American Urological Association Foundation's Astellas Rising Star Award, and the Howard Hughes Medical Institute's Physician-Scientist Early Career Award. The authors have disclosed no relevant financial relationships.

J Clin Oncol. Published online June 17, 2013. Abstract

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