Pathological Analysis of Tumor Response after Preoperative Chemoradiation Therapy for Advanced Rectal Cancer

ABSTRACT

PURPOSE: We investigated the association of survivin expression with the prognosis in advanced rectal cancer with preoperative chemoradiotherapy for pathological analysis. METHODS: We examined 16 patients with rectal cancer who were preoperatively staged as T3 or T4. The enrolled patients were given 5-FU, 425 mg/m2/day, and leucovorin, 20 mg/m2/day, intravenously for 3 days during weeks 1 and 5 of pelvic radiotherapy. Surgical resection was performed 4~6 weeks after completion of the schedule. Tumor response was divided into CR (complete remission), PR (partial remission), and NR (non remission). Immunohistochemical staining of paraffin sections using monoclonal antibodies for survivin, bcl-2, and p53 was performed on pretreatment biopsy and surgically resected tissue by using the standard avidin-biotin-peroxidase technique. RESULTS: No CR was achieved. PR was achieved in 10 patients (62.5%), and NR in 6 patients (37.5%). After preoperative treatment, survivin expression tended to be decreased in tumor cells (62.5% to 31.3%) and slightly increased in adjacent normal mucosa a (12.5% to 25%). After preoperative treatment, survivin expression was correlated with lymph-node metastasis in the statistical analysis. We failed to find any other significant relationship between survivin expression and any parameters, except lymph node metastasis and apoptotic index. CONCLUSIONS: Survivin expression before preoperative treatment was not related to the prognosis in rectal cancer patients, but survivin expression after preoperative treatment was related to lymph node metastasis of advanced rectal cancer. Further studies, including large numbers of rectal cancer cases with a sufficient follow-up period, are needed in order to establish survivin as a prognostic target in rectal cancer.