Background: To clarify the indications for preoperative adjuvant radiotherapy for rectal cancer, the outcome of patients who underwent curative surgery without adjuvant radiotherapy was investigated.
Methods: A total of 817 consecutive patients who underwent curative surgery for clinical stage II or III rectal cancer without preoperative adjuvant radiotherapy between 1988 and 2002 were reviewed.
Results: The actuarial 5-year local recurrence rate in the examined patients was 6.2%. Univariate analysis showed that sex, pathological T classification (pT), clinical N classification (cN), pathological N classification (pN), tumor site, distance from the anal verge, type of surgery, pathological stage, a positive radical margin, lymphatic invasion, and venous invasion were significantly correlated with local recurrence. Multivariate analysis of preoperative factors identified cN, distance from the anal verge, and sex as statistically significant risk factors for local recurrence. In patients with rectal cancer located less than 5 cm from the anal verge and with positive cN, the local recurrence rate was more than 10%.
Conclusions: Patients with rectal cancer located less than 5 cm from the anal verge and with clinically positive lymph nodes should be given preoperative adjuvant radiotherapy.