But VA study finds no mortality increase versus white men

African American men with prostate cancer faced an increased risk of disease progression and definitive treatment versus non-Hispanic white men, but not increased mortality, researchers reported.

In a retrospective analysis of low-risk prostate cancer active surveillance, 3,766 patients experienced disease progression (n=1,156 Black; n=2,610 white), and the cumulative incidence of disease progression at 10 years was 59.69% for African Americans and 48.3% for whites, for a difference of 11.65% (95% CI 9.2%-13.9%, P<0.001), according to Brent S. Rose, MD, of UC San Diego Health, Moores Cancer Center in La Jolla, California, and co-authors.

Additionally, 3,575 men received definitive treatment (n=1,137 African American; n=2,438 white), and the cumulative incidence of definitive treatment at 10 years was 54.8% and 41.4%, respectively, for a difference of 13.4% (95% CI 11%-15.7%, P<0.001), they reported in JAMA.

Finally, 22 African-American and 65 white men died from prostate cancer, for a cumulative incidence of disease-specific mortality at 10 years of 1.1% and 1%, respectively, for a difference of 0.1% (95% CI −0.4% to 0.6%, P=0.82), the authors noted, adding that there also were no differences in non-prostate cancer mortality or all-cause mortality between the two groups.

While the authors stressed that “Longer-term follow-up is needed to better assess the mortality risk,” the findings may still help drive changes in the way prostate cancer is managed in Black patients.

Rose’s group pointed out that “population-based studies indicate that African American men are 2.4 times as likely to die from prostate cancer, compared with white men, due to increased incidence and poorer survival after diagnosis [and] most published studies on clinical outcomes in African American men have generally shown significantly increased progression and need for treatment.”

Given that “the estimates of metastases and prostate cancer-specific mortality for African American men in this cohort are broadly in line with results from prospective cohort studies composed of predominantly white men… African American men should not be excluded from active surveillance protocols,” they wrote.

In an editorial accompanying the study, Ronald C. Chen, MD, MPH, University of Kansas Medical Center in Kansas City, and co-authors agreed that “active surveillance can be safe and effective for Black men.”

But they added that a “cautionary note must be raised regarding generalizing results from the equal-access VHA [Veterans Health Administration] medical centers to more common care contexts.”

And Chen’s group stressed that “Black patients have more biologically aggressive prostate cancer and higher progression rates during active surveillance compared with white men, [so] there is a greater need for Black men in the general population to have access to high-quality and timely care to avoid delays in diagnosing cancer progression and receiving definitive treatment.”

For the study, the authors defined low-risk prostate cancer as a Gleason score of ≤6, clinical tumor stage of ≤2A, and prostate-specific antigen (PSA) level <10 ng/dL. Active surveillance was defined as no definitive treatment within the first year from diagnosis and at least one additional surveillance biopsy.

Race and ethnicity were self-reported by the participants. African American men represented 26.1% of the cohort and had a median age of 63.2 years. The non-Hispanic white men made up 73.9% of the cohort and had a median age of 65.5 years. The median follow-up was 7.6 years.

Rose and co-authors observed that “African American men had a significantly lower median age at diagnosis compared with white men (63.2 versus 65.5 years) and were significantly more likely to present with a lower clinical tumor stage.”

Study endpoints were disease progression, definitive treatment, metastasis, prostate cancer–specific mortality, nonprostate cancer-specific mortality, and all-cause mortality. Disease progression was set as a PSA level increase to ≥10 ng/dL, a pathologic Gleason score >6, or the development of metastases. Progression was identified through medical record analysis.

The authors reported that 109 men were diagnosed with metastatic prostate cancer (n=30 African American; n=79 white). The cumulative incidence of metastasis at 10 years was 1.5% and 1.4%, respectively, for a difference of 0.1% (95% CI, −0.4% to 0.6%, P=0.49).

They also found the following in terms of a cumulative incidence at 10 years of:

  • Non-prostate cancer mortality: 21.2% for 387 African American men; 22.4% for 1,265 white men for a difference of 1.2% (95% CI −0.7% to 3.2%, P=0.14).
  • All-cause mortality: 22.4% for 409 African American men and 23.5% for 1,330 white men for a difference of 1.1% (95% CI −0.9% to 3.1%, P=0.09).

Study limitations included the lack of specific follow-up protocol for active surveillance in the VHA system, and the lack of a protocol for the method or timing of a clinical ascertainment of metastases, according to the authors.

  1. Among African American men with low-risk prostate cancer, active surveillance was associated with increased risk of disease progression and definitive treatment compared with non-Hispanic White men, but not increased mortality.

  2. African American men should not be excluded from active surveillance protocols, bearing in mind that Black patients have more biologically aggressive prostate cancer and higher progression rates during active surveillance compared with white men.

Shalmali Pal, Contributing Writer, BreakingMED™

Rose reported support from the U.S. Department of Defense (DOD) and the NIH. Co-authors reported support from the DOD and the NIH, as well as with Insightec, Endocare, Boston Consulting Group, and Stratify Genomics.

Chen reported relationships with Bayer, Blue Earth Diagnostics, Accuray, AbbVie, Genentech, and Myovant.

Cat ID: 25

Topic ID: 78,25,585,25,192,925