Sphincter-saving surgery with and without pre-operative radiation therapy as treatment for adenocarcinoma of the mid-rectum

Abstract

To determine if pre-operative radiation therapy induces a local response in patients with complete tumour penetration into the rectal wall and allows for anal sphincter preservation, we compared the results from pathological specimens and local recurrences as measurable end-points in patients treated with pre-operative radiation therapy plus low anterior resection vs. those only treated with low anterior resection. From January 1986 to December 1992, we treated 62 patients with mid-rectal adenocarcinoma (5-10 cm from the anal verge as determined by rigid proctosigmoidoscopy with the patient in the jackknife position). Pre-operative evaluation included: complete blood cell count, chemistry profile and the determination of carcinoembryonic antigen, chest X-ray, barium enema or colonoscopy and CT scan of the abdomen and pelvis. Only tumours potentially curative by resection in patients with performance status 0-2 (ECOG) were included. Twenty-one patients received pre-operative radiation therapy at a dose of 45 Gy delivered to the pelvis; 4-8 weeks later a low anterior resection was performed. Forty-one patients were treated with low anterior resection alone. Surgical specimens were classified according to the Astler-Coller modification of Dukes' classification. There were 36 males and 26 females, with a mean age of 56 years. The surgical specimens of those treated only with surgery were classified as: A, 5; B1, 4; B2, 15; C1, 2; and C2, 15. Postirradiated specimens: no residual tumour, 3; A, 4; B1, 4; B2, 7; C2, 3. One surgical death occurred in the group who underwent surgery alone. The median follow-up was 50 months in patients treated with surgery alone vs. 62 months in the combined approach group. Local recurrences occurred in 15/40 patients treated with surgery alone and in 2/21 of those treated with the combined approach (P = 0.043). Anal sphincter continence was classified as excellent by 24/40 patients treated with surgery only and by 18/21 patients treated with the combined approach. The 5-year survival period was 58% in the surgery only group and 82% in the group with combined treatment (P = 0.08). The use of pre-operative radiation therapy plus low anterior resection was associated with a lower rate of local recurrence and with a higher number of surgical specimens with no lymph node metastases. Thus, this combined treatment modality should be further evaluated as a possible treatment of mid-rectal cancers in good surgical candidates selected for sphincter-saving procedures.