Prostate volume index and prostatic chronic inflammation predicted low tumor load in 945 patients at baseline prostate biopsy

Abstract

Purpose: To assess associations of prostate volume index (PVI), defined as the ratio of the volume of the central transition zone to the volume of the peripheral zone of the prostate and prostatic chronic inflammation (PCI) as predictors of tumor load by number of positive cores (PC) in patients undergoing baseline random biopsies.

Methods: Parameters evaluated included age, PSA, total prostate volume, PSA density, digital rectal exam, PVI, and PCI. All patients underwent standard transperineal random biopsies. Tumor load was evaluated as absent (no PC), limited (1-3 PC), and extensive (more than 3 PC). The association of factors with the risk of tumor load was evaluated by the multinomial logistic regression model.

Results: The study evaluated 945 patients. Cancer PC were detected in 477 (507%) cases of whom 207 (43.4%) had limited tumor load and 270 (56.6%) had extensive tumor load. Among other factors, comparing patients with limited tumor load with negative cases, PVI [odds ratio, OR = 0.521, 95% confidence interval (CI) 0.330-0.824; p < 0.005] and PCI (OR = 0.289, 95% CI 0.180-0.466; p < 0.0001) were inversely associated with the PCA risk. Comparing patients with extensive tumor load with negative patients, PVI (OR = 0.579, 95% CI 0.356-0.944; p = 0.028), and PCI (OR = 0.150, 95% CI 0.085-0.265; p < 0.0001), predicted PCA risk. Comparing extensive tumor load with limited tumor load patients, PVI and PCI did not show any association with the tumor load.

Conclusions: Increased PVI and the presence of PCI decreased the risk of increased tumor load and associated with less aggressive prostate cancer biology in patients at baseline random biopsies.

Keywords: Prostate biopsy; Prostate cancer; Prostate tumor grade; Prostate volume index; Prostate-specific antigen; Prostatic chronic inflammation; Tumor volume.