Effects of positive resection margin and tumor distance from anus on rectal cancer treatment outcomes.

Abstract

Rectal cancer outcome depends on stage, technical aspects of surgical excision, and use of adjuvant chemoradiation. Here, we examine effects of positive resection margin and tumor distance from the anus in stage 2 and 3 cancers on 4-year disease-specific survival and recurrence. We reviewed all 495 rectal cancer patients registered in British Columbia in 1996. There were 481 cases analyzed: 29 in situ, 134 stage 1, 107 stage 2, 100 stage 3, 83 stage 4, and 28 unknown stage. Survival was significantly affected by presence of positive resection margin in stage 2 and 3 cancers, P = 0.0001. Lower tumor distance from the anus for stage 2 and 3 cancers worsened survival, P = 0.0007, and overall recurrence, P =0.016, but not local recurrence, P = 0.11. Adjuvant postoperative combined radiation and chemotherapy in stage 2 and 3 cancers significantly improved survival, P = 0.070 and local recurrence, P = 0.018, but not overall recurrence, P = 0.19. Presence of positive resection margin and tumor distance from the anus affect survival, local recurrence, and overall recurrence. Adjuvant postoperative combined radiation and chemotherapy improved our outcomes. Our local recurrence rates for rectal cancers are worse than currently reported standards of less than 10%. Improved surgical excision and use of adjuvant preoperative radiation and chemotherapy may improve outcome.