TREATMENT OF RECTAL-CANCER BY LOW ANTERIOR RESECTION WITH COLOANAL ANASTOMOSIS

Objective Our institution's experience with low anterior resection in combination with coloanal anastomosis (LAR/CAA) for primary rectal can cer was reviewed (1) to determine cancer treatment results, 2) to iden tify risk factors for pelvic recurrence, and 3) to assess the long-ter m success of sphincter preservation. Summary Background Data Use of sp hincter-preserving resection for mid-rectal and selected distal-rectal cancers continues to increase. As surgical techniques and adjuvant th erapy evolve, treatment results must be carefully assessed. Methods On e hundred thirty-four patients treated for primary rectal cancer by LA R/CAA between 1977 and 1990 were studied retrospectively. All patholog ic slides were reviewed. Median follow-up was 4 years. Results Actuari al 5-year survival for all patients was 73%. Among 36 patients who rel apsed, distant metastatic disease had developed at the time of first c linical relapse in most (86%). Pelvic recurrence was detected in 13 pa tients, an actuarial rate of 11% at 5 years. Mesenteric implants, posi tive microscopic resection margin, T3 tumor, perineural invasion, bloo d vessel invasion, and high tumor grade were associated with increased risk for pelvic recurrence. Eleven patients ultimately required perma nent colostomy, and in eight instances the cause was pelvic recurrence . Conclusions Low anterior resection combined with coloanal anastomosi s provides good treatment for mid-rectal cancers and for some distal r ectal cancers. Pelvic recurrence is not associated with short distal r esection margins but is correlated with the presence of histopathologi c markers of aggressive disease in the primary tumor. Long-term preser vation of anal sphincter function depends primarily on control of pelv ic tumor and can be achieved in more than 90% of patients.