Epidemiology, diagnosis and treatment of anterior prostate cancer.

Anterior prostate cancers (APCs) are a group of impalpable neoplasms located in regions anterior to the urethra, which comprise the transition zone, apical peripheral zone and anterior fibromuscular stroma. These regions are typically undersampled using conventional biopsy schemes, leading to a low detection rate for APC and a high rate of false negatives. Radical prostatectomy series suggest prevalence rates of at least 10-30%, but transperineal systematic biopsy is ideal for diagnosis, particularly where multiparametric MRI is unavailable. Combined MRI-targeted and systematic biopsies demonstrate high concordance with final histopathology and lead to the fewest incidences of upgrading and upstaging at radical prostatectomy. Thus, the use of combined biopsy techniques has important implications for preoperative work-up and surgical planning, as APCs are associated with larger cancer volumes and a higher rate of positive surgical margins than posterior prostate cancer. Nevertheless, anterior tumour location might confer a relative resistance to stage progression, as APCs exhibit lower rates of extraprostatic extension, seminal vesical invasion and lymph node metastases than the more commonly seen posterior neoplasms. Few studies have examined the long-term outcomes of partial gland approaches to APCs, but MRI-targeted techniques have the potential to provide real-time intraoperative guidance and maximize the oncological safety of anterior focal treatment options in patients with APC.