Colonic J-pouch function in rectal cancer patients: impact of adjuvant chemoradiotherapy.

PURPOSE: The colonic J-pouch technique of reconstruction optimizes functional outcome after proctectomy with coloanal anastomosis. However, the impact of adjuvant chemoradiation therapy on pouch function in rectal cancer patients has not been investigated.
METHODS: From January 1994 to December 1999, 74 patients with midrectal or low rectal tumors (less than 10 cm from the anal verge) underwent a proctectomy with coloanal anastomosis with colonic J-pouch reconstruction. Chemoradiation was offered in patients with Stage II and III disease. Radiation therapy was administered using a four-field technique including the anal canal, for a total dose of 50.4 Gy (1.8 Gy/fraction/day). Fifteen patients (20 percent) died with metastatic disease, five (6.8 percent) died of other causes without evidence of recurrence, and five (6.8 percent) were lost to follow-up. In addition, two patients had local recurrence (2.7 percent) at the time of follow-up. Forty-five of 47 eligible patients (96 percent) responded to a questionnaire designed to evaluate specifically the degree of continence and pouch evacuation.
RESULTS: The mean age of patients was 68.9 (range, 42-88) years and the mean duration of follow-up was 28.8 (range, 1-69) months. There were 28 patients in the surgery alone group and 17 patients who received either preoperative (13) or postoperative (4) adjuvant chemoradiation therapy. Patients in the surgery alone group had a significantly better degree of continence (mean +/- standard deviation continence score: 18.1 +/- 2.9 vs. 13.3 +/- 4.1, P < 0.001) and were less likely to experience evacuatory problems (mean +/- standard deviation evacuation score: 21.3 +/- 3.7 vs. 16.4 +/- 3.5, P < 0.001). Use of a pad was more frequent in the chemoradiation therapy than in the surgery alone group (53 vs. 18 percent, P = 0.02). The incidence after functional disorders was also more frequent in the irradiated group of patients: incontinence to gas (76 vs. 43 percent, P = 0.03), to liquid stool (64 vs. 25 percent, P = 0.01), and to solid stool (47 vs. 11 percent, P = 0.01). Moreover, irradiated patients reported more frequent pouch-related specific problems, such as clustering (82 vs. 32 percent, P = 0.001), and sensation of incomplete evacuation (82 vs. 32 percent, P = 0.001). Finally, regression analysis demonstrated that radiation-induced sphincter dysfunction was progressive over time.
CONCLUSIONS: Both preoperative and postoperative chemoradiation therapy adversely affects continence and evacuation in patients with colonic J-pouch. Because radiation-induced damage to the normal tissues is known to be cumulative over time, long-term progressive dysfunction of the anal sphincter and neorectum are causes of concern. Consideration should be given to excluding the anal canal from the field of irradiation in patients with Stage II and III rectal cancer, whenever a sphincter-preserving procedure is planned.