[Significance of Surgery for Multidisciplinary Treatment Including Neoadjuvant Chemotherapy for Locally Advanced Colorectal Cancer].

Neoadjuvant chemotherapy has been performed for locally advanced colorectal cancer with invasion to other organs or lateral lymph node metastasis in to control local recurrence and distant metastasis. We evaluated the treatment results and the significance of surgery in 53 patients(36 rectal cancer cases and 17 sigmoid colon cancer cases)who underwent surgery after chemotherapy by XELOX plus bevacizumab for 3 months. As pretreatment diagnosis, 42 cases were T4b and 39 cases were lymph node positive. Combined resection was performed in 34 cases including 12 cases of total pelvic exenteration. Pathological diagnosis showed 27 cases of ypT4b and 34 cases of ypN0. Pathological curative resection was performed in 90.4%. Histological effect by chemotherapy was 31 cases in Grade(Gr)1a, 10 cases in Gr 1b, 8 cases in Gr 2, and 4 cases in Gr 3, respectively. The 5-year survival rate was 60.9% in Gr 1a or lower and 100% in Gr 1b or higher. Tumor markers( CEA and CA19-9)were reduced into normal range after neoadjuvant chemotherapy in all 4 patients with Gr 3. Pathological CR could not be predicted from clinical findings after neoadjuvant chemotherapy. It was suggested that neoadjuvant chemotherapy for locally advanced rectal cancer with invasion to other organs or lateral lymph node metastasis is useful for improving the prognosis, surgical resection is indispensable as a multidisciplinary treatment, and that the pathological therapeutic effect leads to prognosis prediction.