Inflammation, focal atrophic lesions, and prostatic intraepithelial neoplasia with respect to risk of lethal prostate cancer

BACKGROUND: A challenge in prostate cancer (PCa) management is identifying potentially lethal disease at diagnosis. Inflammation, focal prostatic atrophy, and prostatic intraepithelial neoplasia (PIN) are common in prostate tumor specimens, but it is not clear whether these lesions have prognostic significance. METHODS: We conducted a case-control study nested in a cohort of men diagnosed with stage T1a-b PCa through transurethral resection of the prostate in Sweden. Cases are men who died of PCa (n = 228). Controls are men who survived more than 10 years after PCa diagnosis without metastases (n = 387). Slides were assessed for Gleason grade, inflammation, PIN, and four subtypes of focal prostatic atrophy: simple atrophy (SA), postatrophic hyperplasia (PAH), simple atrophy with cyst formation, and partial atrophy. We estimated OR and 95% CI for odds of lethal PCa with multivariable logistic regression. RESULTS: Chronic inflammation and PIN were more frequently observed in tumors with PAH, but not SA. No specific type of atrophy or inflammation was significantly associated with lethal PCa overall, but there was a suggestion of a positive association for chronic inflammation. Independent of age, Gleason score, year of diagnosis, inflammation, and atrophy type, men with PIN were 89% more likely to die of PCa (95% CI: 1.04-3.42). CONCLUSION: Our data show that PIN, and perhaps presence of moderate or severe chronic inflammation, may have prognostic significance for PCa. IMPACT: Lesions in tumor adjacent tissue, and not just the tumor itself, may aid in identification of clinically relevant disease.