Is prostate cancer stage migration continuing for black men in the PSA era?

BACKGROUND: In the United States, disease-specific mortality from prostate cancer (PC) is highest among black men. While the introduction of widespread PSA testing has been associated with a downward stage migration, whether this trend continues in the late PSA era and for black men is unknown. The objective of our study was to evaluate current PC stage migration patterns in the United States by race. METHODS: The Surveillance, Epidemiology and End Results (SEER) registry was queried to obtain all cases of PC reported between 2000 and 2013. Year of diagnosis was categorized into 2000-2003, 2004-2007, 2008-2010 and 2011-2013. Predictors of distant stage PC at diagnosis were determined using logistic regression adjusted for year of diagnosis, age at diagnosis, SEER region and race. RESULTS: A total of 791 184 PC cases were identified. The cohort comprised 78.9% (n=594 920) white and 14.1% (n=106 133) black men. The stage at diagnosis was 83.3% localized, 12.0% regional and 4.7% distant. Age-adjusted incidence demonstrated a steady decline for black men in all time groups while white men had a stable incidence of distant disease between 2000 and 2013. In univariate analysis, black men in the 2004-2007 (OR 0.86 (0.81-0.93)) and 2008-2010 cohorts (OR 0.85 (0.79-0.91)) were less likely to be diagnosed with metastatic PC as compared with the 2000-2003 baseline cohort. In multivariate analysis, the 2004-2007 black cohort was less likely to be diagnosed with distant PC (OR 0.90 (0.84-0.97)). This trend was not observed in white men who in multivariate analysis had an increased risk of distant PC in the 2004-2007 (OR 1.08 (1.04-1.11)), 2008-2010 (OR 1.22 (1.18-1.27)) and 2011-2013 (OR 1.65 (1.59-1.71)) groups. CONCLUSIONS: PC downward stage migration continues in black men but not in white men. Discontinuation of PSA-based screening for PC could disproportionately affect black men.

Long-term oncological outcomes of apical positive surgical margins at radical prostatectomy in the Shared Equal Access Regional Cancer Hospital cohort.

BACKGROUND: Approximately 29-38% of all positive surgical margins (PSMs) at radical prostatectomy (RP) involve the apex. The prognostic significance of apical PSM remains unclear. We therefore compared the long-term oncologic outcomes of men with apical PSMs to those with negative PSMs, apical and other PSMs, and other PSMs at RP. METHODS: The SEARCH (Shared Equal Access Regional Cancer Hospital) database was used to identify 4031 men with prostate cancer (PCa) managed with RP with complete pathologic grade and stage data. Margin status was categorized as negative, apex only, or other positive. Multivariable Cox regression models adjusted for pathologic stage and grade were developed to test the relationship between margin status and biochemical recurrence (BCR), metastases and PCa death. RESULTS: In the final cohort, 34.3% had PSMs, whereas 65.7% had negative margins. Univariable analysis showed that compared with negative margins, apex-only PSM was associated with BCR (hazard ratio (HR): 1.4 [1.1-1.8]), but not metastases or PCa death, whereas apex and other PSMs were associated with BCR (HR: 3.3 [2.8-4]) and metastases (HR: 1.8 [1.02-3.1]) but not PCa death. Nonapical PSMs were associated with BCR (HR: 2.7 [2.4-3.1]), metastases (1.7 [1.2-2.5)] and PCa death (1.8 [1.05-3]). On multivariable analysis, apex-only, apex and other, and nonapical PSMs were associated with BCR but margin status was not associated with metastases or PCa death. CONCLUSIONS: In a large cohort of men undergoing RP, those with PSMs at the prostatic apex had lower BCR, metastases, or PCa death compared with those with PSMs at other locations. When adjusted for pathologic stage and grade, however, PSMs were associated with BCR but not long-term oncologic outcomes. These data confirm that men with apex-only PSMs may not be ideal candidates for adjuvant therapy after RP.

Metformin does not affect risk of biochemical recurrence following radical prostatectomy: results from the SEARCH database.

BACKGROUND: While epidemiologic studies suggest that metformin use among diabetics may decrease prostate cancer (PC) incidence, the effect of metformin use on PC outcome is unclear. We investigated the association between pre-operative metformin use, dose and duration of use and biochemical recurrence (BCR) in PC patients with diabetes who underwent radical prostatectomy (RP). METHODS: We conducted a retrospective cohort analysis within the Shared Equal Access Regional Cancer Hospital (SEARCH) database of 371 PC patients with diabetes who underwent RP. Time to BCR between metformin users and non-users, and by metformin dose and duration of use was assessed using multivariable Cox proportional analysis adjusted for demographic, clinical and/or pathologic features. Time to castrate-resistant PC (CRPC), metastases and PC-specific mortality were explored as secondary outcomes using unadjusted analyses. RESULTS: Of 371 diabetic men, 156 (42%) were using metformin before RP. Metformin use was associated with more recent year of surgery (P<0.0001) but no clinical or pathologic characteristics. After adjustment for year of surgery, clinical and pathologic features, there were no associations between metformin use (hazard ratio (HR) 0.93; 95% confidence interval (CI) 0.61-1.41), high metformin dose (HR 0.96; 95% CI 0.57-1.61) or duration of use (HR 1.00; 95% CI 0.99-1.02) and time to BCR. A total of 14 patients (3.8%) developed CRPC, 10 (2.7%) distant metastases and 8 (2.2%) died from PC. Unadjusted analysis suggested that high metformin dose vs non-use was associated with increased risk of CRPC (HR 5.1; 95% CI 1.6-16.5), metastases (HR 4.8; 95% CI 1.2-18.5) and PC-specific mortality (HR 5.0; 95% CI 1.1-22.5). CONCLUSIONS: Metformin use, dose or duration of use was not associated with BCR in this cohort of diabetic PC patients treated with RP. The suggestion that higher metformin dose was associated with increased risk of CRPC, metastases and PC-specific mortality merits testing in large prospective studies with longer follow-up.

Race is associated with discontinuation of active surveillance of low-risk prostate cancer: results from the Duke Prostate Center.

BACKGROUND: Active surveillance (AS) is increasingly utilized in low-risk prostate cancer (PC) patients. Although black race has traditionally been associated with adverse PC characteristics, its prognostic value for patients managed with AS is unclear. METHODS: A retrospective review identified 145 patients managed with AS at the Duke Prostate Center from January 2005 to September 2011. Race was patient-reported and categorized as black, white or other. Inclusion criteria included PSA <10 ng ml(-1), Gleason sum ≤ 6, and ≤ 33% of cores with cancer on diagnostic biopsy. The primary outcome was discontinuation of AS for treatment due to PC progression. In men who proceeded to treatment after AS, the trigger for treatment, follow-up PSA and biopsy characteristics were analyzed. Time to treatment was analyzed with univariable and multivariable Cox proportional hazards models and also stratified by race. RESULTS: In our AS cohort, 105 (72%) were white, 32 (22%) black and 8 (6%) another race. Median follow-up was 23.0 months, during which 23% percent of men proceeded to treatment. The demographic, clinical and follow-up characteristics did not differ by race. There was a trend toward more uninsured black men (15.6% black, 3.8% white, 0% other, P = 0.06). Black race was associated with treatment (hazard ratio (HR) 2.93, P = 0.01) as compared with white. When the analysis was adjusted for socioeconomic and clinical parameters at the time of PC diagnosis, black race remained the sole predictor of treatment (HR 3.08, P = 0.01). Among men undergoing treatment, the trigger was less often patient driven in black men (8 black, 33 white, 67% other, P = 0.05). CONCLUSIONS: Black race was associated with discontinuation of AS for treatment. This relationship persisted when adjusted for socioeconomic and clinical parameters.

African-American men with low-grade prostate cancer have higher tumor burdens: results from the Duke Prostate Center.

BACKGROUND: To investigate racial differences in tumor burden (cancer volume, cancer percentage and cancer to PSA ratios) in a large cohort of men undergoing radical prostatectomy (RP). METHODS: Demographic, clinical and pathological data of patients undergoing RP between 1993-2010 were reviewed and compared between African-American (AA) and non African-American (nAA) men. Further assessments of pathological tumor burden (estimated tumor volume, percent of cancer involvement, and estimated tumor volume/PSA ratios) were performed across Gleason score categories. RESULTS: Of 4157 patients in the analysis, 604 (14.5%) were AA. Overall, AA patients were younger, had higher Gleason scores, PSA levels and incidence of palpable disease (all P < 0.001). Despite comparable prostate weights (39.4 vs. 39.6 g), AA men had higher percent cancer involvement and estimated tumor volume (all P < 0.001) but similar estimated tumor volume/PSA ratios ( P> 0.05). When stratified by Gleason scores, prostate weights were comparable; however, estimated tumor volume, percent cancer involvement and estimated tumor volume/PSA ratios were higher in AA men with low grade (≤ 6) prostate cancer (PCa), similar in intermediate grade (7-8) and lower in high grade (9-10) PCa compared to nAA men. CONCLUSIONS: In this large series, AA patients had higher disease burden (estimated tumor volume, percent cancer involvement, estimated tumor volume/PSA ratios) compared to nAA but this association was especially pronounced in low grade (Gleason ≤ 6) cancers. These data depict a complex picture of relations between race and tumor burden across the spectrum of PCa aggressiveness. Further investigation is warranted to understand the mechanisms of racial disparities in PCa.