Rates of metastatic prostate cancer in newly diagnosed patients: Numbers needed to image according to risk level.

BACKGROUND: The numbers needed to image to identify pelvic lymph node and/or distant metastases in newly diagnosed prostate cancer (PCa) patients according to risk level are unknown. METHODS: Relying on Surveillance, Epidemiology, and End Results (2010-2016), we tabulated rates and proportions of patients with (a) lymph node or (b) distant metastases according to National Comprehensive Cancer Network (NCCN) risk level and calculated the number needed to image (NNI) for both endpoints. Multivariable logistic regression analyses were performed. RESULTS: Of 145,939 newly diagnosed PCa patients assessable for analyses of pelvic lymph node metastases (cN1), 4559 (3.1%) harbored cN1 stage: 13 (0.02%), 18 (0.08%), 63 (0.3%), 512 (2.8%), and 3954 (14.9%) in low, intermediate favorable, intermediate unfavorable, high, and very high-risk levels. These resulted in NNI of 4619, 1182, 319, 35, and 7, respectively. Of 181,109 newly diagnosed PCa patients assessable for analyses of distant metastases (M1a-c ), 8920 (4.9%) harbored M1a-c stage: 50 (0.07%), 45 (0.1%), 161 (0.5%), 1290 (5.1%), and 7374 (22.0%) in low, intermediate favorable, intermediate unfavorable, high, and very high-risk. These resulted in NNI of 1347, 602, 174, 20, and 5, respectively. CONCLUSIONS: Our observations perfectly validated the NCCN recommendations for imaging in newly diagnosed high and very high-risk PCa patients. However, in unfavorable intermediate-risk PCa patients, in whom bone and soft tissue imaging is recommended, the NNI might be somewhat elevated to support routine imaging in clinical practice.

Incidental prostate cancer after transurethral resection of the prostate: analysis of incidence and risk factors in 458 patients.

BACKGROUND: The aim of this study is to evaluate the incidence and risk factors of incidental prostate cancer (IPCA) in a contemporary cohort of lower urinary tract symptoms (LUTS) patients who underwent trans-urethral resection of the prostate (TURP). METHODS: A series of 458 consecutive patients who underwent TURP were evaluated between January 2016 to June 2018. Evaluated factors included age (years), Body Mass Index (BMI; kg/square meters), treatment with inhibitors of 5-alpha reductase, previous prostate biopsies, basal prostate specific antigen (PSA) levels (ng/mL), serum leukocyte count (×109/L), weight of resected prostate tissue (grams), grade and stage of IPCA. The multivariate logistic regression model evaluated associations of significant clinical factors with the risk of IPCA. RESULTS: Overall, IPCA was detected in 30 of 454 patients (6.6%). A mean of 21.8 g of tissue was resected. The mean number of positive chips was 5.6 (mean percentage 3.9%) with tumor grade group 1 in 22 cases (73.4%) and tumor stage cT1a in 23 patients (76.7%). On multivariate analysis, independent factors that were positively associated with the risk of IPCA were BMI (odds ratio, OR=1.121; P=0.017) and leukocyte count (OR=1.144; P=0.027). CONCLUSIONS: In a contemporary cohort of patients undergoing TURP for the treatment of LUTS, the risk of IPCA was not negligible with a rate of being 6.6%. BMI and serum leukocyte count were found to be independent factors that were positively associated with the risk of IPCA.