Chronic inflammation tied to lower tumour grade in prostate cancer

Chronic baseline prostate inflammation in a negative biopsy is predictive of a lower prostate cancer grade among men with cancer on follow-up 2-year biopsy, a study has shown.

A total of 889 men aged 50–75 years with negative baseline prostate biopsy and 2-year repeat biopsy positive for prostate cancer in the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) study were included in retrospective analyses. Central pathology during the REDUCE study ascertained acute and chronic prostate inflammation and cancer grade.

The authors evaluated the association of inflammation at baseline with prostate cancer grade in 2-year repeat biopsy using Student’s t-test, chi-squared test, and multivariable logistic regression.

Chronic, acute inflammation, and both were detected in 533 (60 percent), 12 (1 percent), and 85 (10 percent) baseline biopsies, respectively. The presence of acute and chronic inflammation significantly correlated with each other (p<0.001). Both inflammation types, however, were not associated with race, body mass index, prostate-specific antigen, or digital rectal exam.

At the 2-year biopsy, 621 (70 percent) and 268 (30 percent) tumours were low grade (Gleason scores 2–6) and high grade (Gleason scores 7–10), respectively.

Univariate and multivariate analyses showed significantly fewer high-grade tumours in men with baseline chronic inflammation (univariable odds ratio [OR], 0.64, 95 percent confidence interval [CI], 0.47–0.87; p=0.004; multivariable OR, 0.68, 95 percent CI, 0.50–0.93; p=0.016) than in those without baseline chronic inflammation.

On the other hand, baseline acute inflammation did not correlate with tumour grade (univariable OR, 0.74, 95 percent CI, 0.45–1.20; p=0.22; multivariable OR, 0.78, 95 percent CI, 0.48–1.29; p=0.34).