A Prospective Study of Chronic Inflammation in Benign Prostate Tissue and Risk of Prostate Cancer: Linked PCPT and SELECT Cohorts.

Publication Type:

Journal Article

Source:

Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology (2017)

Abstract:

BACKGROUND: We leveraged two trials to test the hypothesis of an inflammation-prostate cancer link prospectively in men without indication for biopsy.

METHODS: Prostate Cancer Prevention Trial (PCPT) participants who had an end-of-study biopsy performed per protocol that was negative for cancer and who subsequently enrolled in the Selenium and Vitamin E Cancer Prevention Trial (SELECT) were eligible. We selected all 100 cases and sampled 200 frequency-matched controls and used PCPT end-of-study biopsies as "baseline". Five men with PSA >4 ng/mL at end-of-study biopsy were excluded. Tissue was located for 92 cases and 193 controls. We visually assessed inflammation in benign tissue. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) using logistic regression adjusting for age and race.

RESULTS: Mean time between biopsy and diagnosis was 5.9 years. In men previously in the PCPT placebo arm, 78.1% of cases (N=41) and 68.2% of controls (N=85) had at least one baseline biopsy core (~5 evaluated per man) with inflammation. The odds of prostate cancer (N=41 cases) appeared to increase with increasing mean percentage of tissue area with inflammation, a trend that was statistically significant for Gleason sum <4+3 disease (N=31 cases; versus 0%, >0-<1.8% OR=1.70, 1.8%-<5.0% OR=2.39, ≥5% OR=3.31, p-trend=0.047). In men previously in the finasteride arm, prevalence of inflammation did not differ between cases (76.5%; N=51) and controls (75.0%; N=108).

CONCLUSIONS: Benign tissue inflammation was positively associated with prostate cancer.

IMPACT: This first prospective study of men without biopsy indication supports the hypothesis that inflammation influences prostate cancer development.