Predictors of recurrence after local excision and postoperative chemoradiation therapy of adenocarcinoma of the rectum

Background: Local excision of rectal cancer preserves anal continence, bladder function, and normal sexual function. However, local recurrence after excision remains a significant problem. To further define the indications for local excision, we analyzed possible factors predictive of recurrence after local excision of rectal cancer. Methods: The charts of all patients undergoing local excision of adenocarcinoma of the rectum between 1985 and 1995 at a single institution were reviewed. Patients with metastatic disease at the time of excision and patients treated preoperatively with chemoradiation therapy were excluded. All available slides were reviewed by a single pathologist, who assessed the depth of invasion; the presence or absence of vascular invasion, lymphatic invasion, perineural invasion, and lymphocytic infiltrate; the mucinous status; and the degree of differentiation. Using the log-rank test and Cox proportional hazards model, univariate and multivariate analyses were performed to identify predictors of recurrence. Results: Ninety patients underwent local excision, 46 transanally and 44 using a Kraske approach. The breakdown of patients by tumor stage was as follows: Tis, 13%; T1, 41%; T2, 30%; T3, 15%; and Tx, 1%. Sixty-eight percent of patients with T1 tumors were treated with postoperative radiotherapy; all patients with T2 or T3 tumors were treated postoperatively with or without 5-fluorouracil. The median duration of follow-up was 51 months. The median tumor diameter was 2.5 cm (range, 0.4 to 7 cm), and the median distance of the tumor from the anal verge was 4.5 cm (range, 1 to 10 cm). The 4-year actuarial local disease-free survival rate broken down by tumor stage was as follows: Tis, 100%; T1, 95%; T2, 80%; and T3, 73%. The median time to local recurrence was 23 months (range, 7 to 61 months). Multivariate analysis showed that only tumor stage and margin status were predictors of local recurrence. Conclusions: Local excision and postoperative radiotherapy result in adequate local control of early stage (Tis and T1) adenocarcinoma of the rectum. Higher rates of recurrence were seen in patients with T2 and T3 tumors, especially in those with positive margins.