Selection and Outcomes in Abdominoperineal Resection

Summary Background Local recurrence rates in operable rectal cancer are improved by radiotherapy (with or without chemotherapy) and surgical techniques such as total mesorectal excision. However, the contributions of surgery and radiotherapy to outcomes are unclear. We assessed the effect of the involvement of the circumferential resection margin and the plane of surgery achieved. Methods In this prospective study, the plane of surgery achieved and the involvement of the circumferential resection margin were assessed by local pathologists, using a standard pathological protocol in 1156 patients with operable rectal cancer from the CR07 and NCIC-CTG CO16 trial, which compared short-course (5 days) preoperative radiotherapy and selective postoperative chemoradiotherapy, between March, 1998, and August, 2005. All analyses were by intention to treat. This trial is registered, number ISRCTN 28785842. Findings 128 patients (11%) had involvement of the circumferential resection margin, and the plane of surgery achieved was classified as good (mesorectal) in 604 (52%), intermediate (intramesorectal) in 398 (34%), and poor (muscularis propria plane) in 154 (13%). We found that both a negative circumferential resection margin and a superior plane of surgery achieved were associated with low local recurrence rates. Hazard ratio (HR) was 0·32 (95% CI 0·16–0·63, p=0·0011) with 3-year local recurrence rates of 6% (5–8%) and 17% (10–26%) for patients who were negative and positive for circumferential resection margin, respectively. For plane of surgery achieved, HRs for mesorectal and intramesorectal groups compared with the muscularis propria group were 0·32 (0·16–0·64) and 0·48 (0·25–0·93), respectively. At 3 years, the estimated local recurrence rates were 4% (3–6%) for mesorectal, 7% (5–11%) for intramesorectal, and 13% (8–21%) for muscularis propria groups. The benefit of short-course preoperative radiotherapy did not differ in the three plane of surgery groups (p=0·30 for trend). Patients in the short-course preoperative radiotherapy group who had a resection in the mesorectal plane had a 3-year local recurrence rate of only 1%. Interpretation In rectal cancer, the plane of surgery achieved is an important prognostic factor for local recurrence. Short-course preoperative radiotherapy reduced the rate of local recurrence for all three plane of surgery groups, almost abolishing local recurrence in short-course preoperative radiotherapy patients who had a resection in the mesorectal plane. The plane of surgery achieved should therefore be assessed and reported routinely. Funding Medical Research Council (UK) and the National Cancer Institute of Canada.

Treatment of rectal cancer has changed dramatically over the last decade. The worldwide introduction of total mesorectal excision in combination with the increasing use of radio(chemo)-therapy has led to an improved prognosis. One of the main prognostic factors in rectal cancer is the circumferential resection margin (CRM). Since the initial description of its clinical importance in 1986, the involvement of this margin (also called lateral or radial resection margin) has been associated with a poor prognosis. In the current review, the evidence for the importance of the CRM in more than 17,500 patients is reviewed, and the relevance of this assessment to modern treatment is assessed. We demonstrate that, after neoadjuvant therapy (both radiotherapy and radiochemotherapy), the predictive value of the CRM for local recurrence is significantly higher than when no preoperative therapy has been applied (hazard ratio [HR] = 6.3 v 2.0, respectively; P < .05). Furthermore, involvement of the CRM is a powerful predictor of both development of distant metastases (HR = 2.8; 95% CI, 1.9 to 4.3) and survival (HR = 1.7; 95% CI, 1.3 to 2.3). In addition to the prognostic data, this review describes different modes of margin involvement, exact definitions, and factors influencing its presence. CRM involvement is one of the key factors in rectal cancer treatment.

To examine the role of total mesorectal excision in the management of rectal cancer. A prospective consecutive case series. A district hospital and referral center in Basingstoke, England. Five hundred nineteen surgical patients with adenocarcinoma of the rectum treated for cure or palliation. Anterior resections (n = 465) with low stapled anastomoses (407 total mesorectal excisions), abdominoperineal resections (n = 37), Hartmann resections (n = 10), local excisions (n = 4), and laparotomy only (n = 3). Preoperative radiotherapy was used in 49 patients (7 with abdominoperineal resections, 38 with anterior resections, 3 with Hartmann resections, and 1 with laparotomy). Local recurrence and cancer-specific survival. Cancer-specific survival of all surgically treated patients was 68% at 5 years and 66% at 10 years. The local recurrence rate was 6% (95% confidence interval, 2%-10%) at 5 years and 8% (95% confidence interval, 2%-14%) at 10 years. In 405 "curative" resections, the local recurrence rate was 3% (95% confidence interval, 0%-5%) at 5 years and 4% (95% confidence interval, 0%-8%) at 10 years. Disease-free survival in this group was 80% at 5 years and 78% at 10 years. An analysis of histopathological risk factors for recurrence indicates only the Dukes stage, extramural vascular invasion, and tumor differentiation as variables in these results. Rectal cancer can be cured by surgical therapy alone in 2 of 3 patients undergoing surgical excision in all stages and in 4 of 5 patients having curative resections. In future clinical trials of adjuvant chemotherapy and radiotherapy, strategies should incorporate total mesorectal excision as the surgical procedure of choice.