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

Background: Local excision of rectal cancer preserves anal continence, blad der function, and normal sexual function. However, local recurrence after e xcision remains a significant problem. To further define the indications fo r local excision, we analyzed possible factors predictive of recurrence aft er local excision of rectal cancer. Methods: The charts of all patients undergoing local excision of adenocarci noma of the rectum between 1985 and 1995 at a single institution were revie wed. Patients with metastatic disease at the time of excision and patients treated preoperatively with chemoradiation therapy were excluded. All avail able slides were reviewed by a single pathologist, who assessed the depth o f invasion; the presence or absence of vascular invasion, lymphatic invasio n, perineural invasion,and lymphocytic infiltrate; the mucinous status; and the degree of differentiation. Using the log-rank test and Cox proportiona l hazards model, univariate and multivariate analyses were performed to ide ntify predictors of recurrence. Results: Ninety patients underwent local excision, 46 transanally and 44 us ing a Kraske approach. The breakdown of patients by tumor stage was as foll ows: Tis, 13%; T1, 41%; T2, 30%; T3, 15%; and Tx, 1%. Sixty-eight percent o f 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 a ctuarial 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 loca l recurrence was 23 months (range, 7 to 61 months). Multivariate analysis s howed that only tumor stage and margin status were predictors of local recu rrence. Conclusions: Local excision and postoperative radiotherapy result in adequa te 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, esp ecially in those with positive margins.