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Background A total of 10%–20% of patients develop long-term toxicity following radiotherapy for prostate cancer. Identification of common genetic variants associated with susceptibility to radiotoxicity might improve risk prediction and inform functional mechanistic studies. Methods We conducted an individual patient data meta-analysis of six genome-wide association studies (n = 3871) in men of European ancestry who underwent radiotherapy for prostate cancer. Radiotoxicities (increased urinary frequency, decreased urinary stream, hematuria, rectal bleeding) were graded prospectively. We used grouped relative risk models to test associations with approximately 6 million genotyped or imputed variants (time to first grade 2 or higher toxicity event). Variants with two-sided Pmeta less than 5 × 10−8 were considered statistically significant. Bayesian false discovery probability provided an additional measure of confidence. Statistically significant variants were evaluated in three Japanese cohorts (n = 962). All statistical tests were two-sided. Results Meta-analysis of the European ancestry cohorts identified three genomic signals: single nucleotide polymorphism rs17055178 with rectal bleeding (Pmeta = 6.2 × 10−10), rs10969913 with decreased urinary stream (Pmeta = 2.9 × 10−10), and rs11122573 with hematuria (Pmeta = 1.8 × 10−8). Fine-scale mapping of these three regions was used to identify another independent signal (rs147121532) associated with hematuria (Pconditional = 4.7 × 10−6). Credible causal variants at these four signals lie in gene-regulatory regions, some modulating expression of nearby genes. Previously identified variants showed consistent associations (rs17599026 with increased urinary frequency, rs7720298 with decreased urinary stream, rs1801516 with overall toxicity) in new cohorts. rs10969913 and rs17599026 had similar effects in the photon-treated Japanese cohorts. Conclusions This study increases the understanding of the architecture of common genetic variants affecting radiotoxicity, points to novel radio-pathogenic mechanisms, and develops risk models for testing in clinical studies. Further multinational radiogenomics studies in larger cohorts are worthwhile.

Herein, the authors compare morbidity in men who underwent both transrectal ultrasound–guided (TRUS) prostate biopsy and transperineal mapping biopsy (TPMB) at two institutions with extensive experience in both procedures. We also identified strategies and predictive factors to reduce morbidity for both procedures. In our study, 379 men from two institutions, of which 265 (69.9%) had a prior TRUS-guided biopsy, also had TPMB performed via a template with biopsies taken at 5-mm intervals. Men in the TRUS group had a median of 12 cores sampled whereas the TPMB group had 51.5 (range, 16-151). The median biopsy density was 1.1 core/cc prostate volume. Median age and prostate-specific antigen (PSA) level were 65 years (range, 34-86) and 5.5 ng/mL (range, 0.02-118). Of these men, 11 of 265 (4.2%) who had TRUS biopsy developed urinary tract infection compared with 3 of 379 (0.79%) of those with mapping biopsy. Infection was 14.8% in TRUS biopsy group with 13 or more cores versus 2.9% in those with 12 or less (OR, 5.8; 95% CI, 1.6-21.2; P = 0.003). No men developed retention after TRUS biopsy whereas 30 of 379 (7.9%) did following TPMB. Older age, larger prostate volume (PV), and higher core number were associated with retention. On linear regression only age (P = 0.010) and PV (P = 0.016) remained as significant associations. Men older than 65 years had 12.8% versus 3.9% (OR, 3.7; 95% CI, 1.6-8.4, P = 0.001) and PV greater than 42 cc had 13.4% versus 2.7% (OR, 5.7; 95% CI, 2.1-15.1) retention incidence. In the present study TPMB is rarely associated with infection (0.78%) but more commonly with urinary retention (7.9%). Men older than 65 years and with PV greater than 42 cc were at four to five times greater retention risk. Consideration should be given to discharging these men with a urinary catheter following TPMB.

Objective: To offer recommendations on identification of disease progression, treatment management strategies, and suggestions on timing of initiating and discontinuing specific CRPC treatments.Materials and Methods: The RADAR II [Prostate Cancer Radiographic Assessments for Detection of Advanced Recurrence] Working Group convened to provide guidance on sequencing, combination, or layering of approved treatments for mCRPC based on available data and clinical experience.Results: A consensus was developed to address important questions on mCRPC patient management.Conclusions: In the absence of large scale clinical trials, the Working Group recommends that patients may best be managed with a layered approach of approved therapies with unique or complimentary mechanisms of action.

Nearly 50% of cancer patients undergo radiotherapy. Late radiotherapy toxicity affects quality-of-life in long-term cancer survivors and risk of side-effects in a minority limits doses prescribed to the majority of patients. Development of a test predicting risk of toxicity could benefit many cancer patients. We aimed to meta-analyze individual level data from four genome-wide association studies from prostate cancer radiotherapy cohorts including 1564 men to identify genetic markers of toxicity. Prospectively assessed two-year toxicity endpoints (urinary frequency, decreased urine stream, rectal bleeding, overall toxicity) and single nucleotide polymorphism (SNP) associations were tested using multivariable regression, adjusting for clinical and patient-related risk factors. A fixed-effects meta-analysis identified two SNPs: rs17599026 on 5q31.2 with urinary frequency (odds ratio [OR] 3.12, 95% confidence interval [CI] 2.08-4.69, p-value 4.16×10(-8)) and rs7720298 on 5p15.2 with decreased urine stream (OR 2.71, 95% CI 1.90-3.86, p-value=3.21×10(-8)). These SNPs lie within genes that are expressed in tissues adversely affected by pelvic radiotherapy including bladder, kidney, rectum and small intestine. The results show that heterogeneous radiotherapy cohorts can be combined to identify new moderate-penetrance genetic variants associated with radiotherapy toxicity. The work provides a basis for larger collaborative efforts to identify enough variants for a future test involving polygenic risk profiling.

This comprehensive text provides a complete description of the newest technologies to diagnose and manage the most common prostate cancer diagnosed today: low risk disease. The book reviews new data about genetic markers, transperineal mapping biopsy and mpMRI, how to apply each of these technologies in patients with elevated PSA, when a prior prostate biopsy performed by the standard TRUS method is negative, and, in cases where low risk disease is already diagnosed, how to differentiate those men who might harbor more aggressive disease from those who do not. Over 75% of newly diagnosed prostate cancer meets the criteria for low risk disease which has created a dilemma for both patients and clinicians because of the inaccuracy of the standard TRUS biopsy method. Active surveillance programs have been initiated and are reviewed. How the new technologies impact surveillance programs are addressed. Clinical stage designation is updated and a new intra-prostatic staging system is discussed. Prostate biopsy techniques utilizing transrectal ultrasound, transperineal mapping, elastography and mpMRI are compared. Finally, utilization of these new technologies in the application of focal therapy is reviewed. The Prostate Cancer Dilemma will serve as a valuable resource for clinicians, surgeons and researchers with an interest in early prostate cancer. Chapters are written by experts in their fields and include the most up-to-date scientific and clinical information as well as links to procedural video content.