[COMBINED SURGERY FOR RECTAL CANCER WITH PROSTATIC INVASION : A CASE REPORT].

A 58-year-old man presented with anal pain and fecal incontinence. He was diagnosed with locally advanced rectal cancer (cT4bN3M0) with prostate invasion and referred for combined surgery. Robotic abdominoperineal resection and retzius-sparing robot-assisted radical prostatectomy (RS-RARP) were performed. On postoperative day 14, cystography showed no evidence of vesicourethral anastomotic leakage, and the urethral catheter was removed. The postoperative course was uneventful without urinary incontinence. Pathological findings confirmed prostate invasion with negative surgical margins. Adjuvant chemotherapy was administered, and no recurrence has been observed at one year. In cases of rectal cancer with prostate invasion, concomitant prostate and seminal vesicle resection is often required, which carries a high risk of vesicourethral leakage and incontinence. RS-RARP preserves the anterior structures of the prostate and may reduce the risk of anastomotic failure while maintaining continence and sexual function. This case suggests that RS-RARP combined with APR could be a feasible surgical option for achieving curative resection and functional preservation in selected patients with locally advanced rectal cancer invading the prostate.