Outcome for stage II and III rectal and colon cancer equally good after treatment improvement over three decades

Purpose This study aimed to investigate the outcome for stage II and III rectal cancer patients compared to stage II and III colonic cancer patients with regard to 5-year cause-specific survival (CSS), overall survival, and local and combined recurrence rates over time. Methods This prospective cohort study identified 3,355 consecutive patients with adenocarcinoma of the colon or rectum and treated in our colorectal unit between 1981 and 2011, for investigation. The study was restricted to International Union Against Cancer (UICC) stages II and III. Postoperative mortality and histological incomplete resection were excluded, which left 995 patients with colonic cancer and 726 patients with rectal cancer for further analysis. Results Five-year CSS rates improved for colonic cancer from 65.0 % for patients treated between 1981 and 1986 to 88.1 % for patients treated between 2007 and 2011. For rectal cancer patients, the respective 5-year CSS rates improved from 53.4 % in the first observation period to 89.8 % in the second one. The local recurrence rate for rectal cancer dropped from 34.2 % in the years 1981–1986 to 2.1 % in the years 2007–2011. In the last decade of observation, prognosis for rectal cancer was equal to that for colon cancer (CSS 88.6 vs. 86.7 %, p = 0.409). Conclusion Survival of patients with colon and rectal cancer has continued to improve over the last three decades. After major changes in treatment strategy including introduction of total mesorectal excision and neoadjuvant (radio)chemotherapy, prognosis for stage II and III rectal cancer is at least as good as for stage II and III colonic cancer.