Delayed coloanal anastomosis: an alternative option for restorative rectal cancer surgery after high-dose pelvic radiotherapy for prostate cancer.

Aim: Restorative total mesorectal excision (TME) for rectal cancer after high-dose pelvic radiotherapy for prostate cancer has been reported to provide an unacceptable rate of pelvic sepsis. In a previous publication we proposed that delayed coloanal anastomosis (DCAA) should be performed in this situation. The present study aimed to assess the feasibility and outcomes of this strategy.

Method: Between 2000 and 2018, 1094 men were operated on for rectal cancer in our institution. All men with T2/T3 mid and low rectal cancer with preoperative radiotherapy and restorative TME were considered for this study (n = 416). Patients with external-beam high-dose radiotherapy (EBHRT) for prostate cancer (70-78 Gy) were identified and compared with patients with conventional long-course chemoradiotherapy (CRT) followed by TME. We compared our already published historical cohort (2000-2012), including arm A (CRT + TME; n = 236) and arm B (EBHRT + TME; n = 12), with our early cohort (2013-2018), including arm C (CRT + TME; n = 158) and arm D (EBHRT + TME-DCAA; n = 10). The end-points were morbidity, pelvic sepsis, reoperation rate and quality of the specimen.

Results: Overall morbidity was not significantly different between groups. Pelvic sepsis decreased from 50% (arm B) to 10% (arm D) with the use of DCAA (P = 0.074), and was similar between arms A, C and D. Quality of the specimen was not significantly different between the four groups.

Conclusion: Our results suggest that TME with DCAA in patients with previous EBHRT is feasible, with the same postoperative pelvic sepsis rate as conventional CRT.