Although well described, there is limited published data related to management on the coexistence of prostate and rectal cancer. The aim of this study was to describe a single institution's experience with this and propose a treatment algorithm based on the best available evidence.

From 2000 to 2011, a retrospective review of institutional databases was performed to identify patients with synchronous prostate and rectal cancers where the rectal cancer lay in the lower two thirds of the rectum. Operative and non-operative outcomes were analysed and a management algorithm is proposed.

Twelve patients with prostate and rectal cancer were identified. Three were metachronous diagnoses (>3-month time interval) and nine were synchronous diagnoses. In the synchronous group, four had metastatic disease at presentation and were treated symptomatically, while five were treated with curative intent. Treatment included pelvic radiotherapy (74 Gy) followed by pelvic exenteration (three) and watchful waiting for rectal cancer (one). The remaining patient had a prostatectomy, long-course chemoradiotherapy and anterior resection. There were no operative mortalities and acceptable morbidity. Three remain alive with two patients disease-free.

Synchronous detection of prostate cancer and cancer of the lower two thirds of the rectum is uncommon, but likely to increase with rigorous preoperative staging of rectal cancer and increased awareness of the potential for synchronous disease. Treatment must be individualized based on the stage of the individual cancers taking into account the options for both cancers including EBRT (both), surgery (both), hormonal therapy (prostate), surgery (both) and watchful waiting (both).