Background Magnetic resonance imaging (MRI) scans are increasingly first-line investigations for suspected prostate cancer, and essential in the decision for biopsy. 5-alpha reductase inhibitor (5-ARI) use has been shown to reduce prostate size and prostate cancer risk. However, insufficient data exists on how 5-ARI use affects MRI findings and yield of biopsy. This study explores the differences in imaging and prostate cancer diagnoses between patients receiving and not receiving 5-ARI therapy. Methods From 2015 to 2020, we collected retrospective data of consecutive patients undergoing prostate biopsy at one centre. We included patients who were biopsy-naïve, had prior negative biopsies, or on active surveillance for low-grade prostate cancer. Clinical and pathological data was collected, including 5-ARI use, Prostate Imaging Reporting and Data System (PIRADS) classification and biopsy results. Results 351 men underwent saturation biopsy with or without targeted biopsies. 54 (15.3%) had a history of 5-ARI use. On mpMRI, there was no significant difference between the 5ARI and non-5-ARI groups in PIRADS distribution, number of lesions, and lesion location. Significantly fewer cancers were detected in the 5-ARI group (46.3% vs. 68.0%; p < 0.01). There were no significant differences in PIRADS distribution in 5-ARI patients with positive and negative biopsy. Conclusion Our study found significant differences in biochemical, imaging and biopsy characteristics between 5-ARI and non-5-ARI groups. While both groups had similar PIRADS distribution, 5-ARI patients had a lower rate of positive biopsies across all PIRADS categories, which may suggest that the use of 5ARI may confound MRI findings. Further studies on how 5-ARI therapy affects the imaging characteristics of prostate cancer should be performed.

FISH = fluorescence in situ hybridization HR = hazard ratio IL = interleukin IQR = interquartile range LMR = lymphocyte-to-monocyte ratio NAL = neoantigen load NLR = neutrophil-to-lymphocyte ratio NMIBC = non-muscle invasive bladder cancer OR = odds ratio PD-L1 = programmed deathligand 1 PLR = platelet-to-lymphocyte ratio SNP = single-nucleotide polymorphism TMB = tumor mutation burden TME = tumor microenvironment TSG = tumor suppressor gene TURBT = transurethral resection of bladder tumor

ObjectiveTo perform a systematic review and meta‐analysis to evaluate the impact of body mass index (BMI) on oncological (primary) and surgical (secondary) outcomes of patients who underwent nephrectomy, as obesity or high BMI is a known risk factor for renal cell carcinoma (RCC) and predictor of poorer outcomes.MethodsStudies were identified from four electronic databases from database inception to 2 June 2021, according to the Preferred Reporting Items for Systematic Review and Meta‐analysis statement. The review protocol was registered in the International Prospective Register of Systematic Reviews with the identification number: CRD42021275124.ResultsA total of 18 studies containing 13 865 patients were identified for the final meta‐analysis. Regarding oncological outcomes, higher BMI predicted higher overall survival (BMI >25 vs BMI <25 kg/m2: hazard ratio [HR] 0.70, 95% confidence interval [CI] 0.58–0.85), cancer‐specific survival (BMI >25 vs BMI <25 kg/m2: HR 0.60, 95% CI 0.50–0.73; BMI 25–30 vs BMI <25 kg/m2: HR 0.46, 95% CI 0.23–0.95; BMI >30 vs BMI <25 kg/m2: HR 0.50, 95% CI 0.36–0.69), and recurrence‐free survival rates (BMI >25 vs BMI <25 kg/m2: HR 0.72, 95% CI 0.63–0.82; BMI 25–30 vs BMI <25 kg/m2: HR 0.59, 95% CI 0.42–0.82). Those with a lower BMI fared better in surgical outcomes, such as operation time and warm ischaemic time, although the absolute difference was minimal and unlikely to be clinically significant. There was no difference between groups for length of hospital stay, intraoperative or postoperative complications, blood transfusion requirements, and conversion to open surgery.ConclusionOur study suggests that a higher BMI is associated with improved long‐term oncological survival and similar perioperative outcomes as a lower BMI. More research into the underlying biological and physiological mechanisms will enable better understanding of the effect of BMI, beyond mere association, on post‐nephrectomy outcomes.