Predictive value of prostate calcification for future cancer occurrence: a retrospective long-term follow-up cohort study

Objective: Although prostate calcification is often identified on pelvic CT images, calcification itself is usually not considered clinically significant. A recent histological study proposed an association between prostate calcification and prostate cancer occurrence. Our aim was to determine the predictive value of prostate calcifications for future prostate cancer occurrence. Methods: We retrospectively analysed male patients (≥50 years old) without prior prostate cancer history, who underwent unenhanced pelvic CT between April 2010 and March 2011, and followed-up until December 2021. Cox proportional hazards models were used to assess prostate cancer risk with prostate calcification (defined as a high-density area larger than 3 mm with CT attenuation values ≥ 130 HU), controlling for age, body mass index (BMI), hypertension and diabetes mellitus. Results: A total of 636 male patients (mean age, 68 years ± 9 [standard deviation]) were evaluated. At the end of follow-up, prostate cancer had been more frequently diagnosed in patients with prostate calcification than those without prostate calcification (6.5% vs  2.6%). Multivariate analysis revealed that prostate calcification on CT was a significant predictor of future prostate cancer occurrence (hazard ratio [HR], 2.7; 95% CI: 1.20, 5.91; p = 0.016). No statistical differences were observed in any other factors. Conclusion: Prostate calcification may be a significant predictor of future prostate cancer occurrence, and may be used for risk stratification and to guide screening protocols. Advances in knowledge: Presence of prostate calcification on unenhanced CT scan was associated with increased incidence of prostate cancer occurrence on long term follow-up.