[Examination of Prognosis and Adjuvant Chemotherapy in Stage â ¡ and Stage â ¢ Resected Colorectal Cancer in the 9th Edition Japanese Classification of Colorectal Carcinoma].

In the 9th edition Japanese Classification of Colorectal Carcinoma, Stage Ⅱ and Stage Ⅲ colorectal cancer(CRC)were subdivided by TNM classification on invasion and number of lymph node metastases. We studied prognostic comparison and relation of adjuvant chemotherapy at the new classification. We included 400 cases with resected Ⅱ and Ⅲ CRC from 2007 to 2014. Ⅱa/Ⅱb/Ⅱc/Ⅲa/Ⅲb/Ⅲc were 97/68/20/24/124/67 cases. Adjuvant chemotherapy was performed at 19/32/45/66/59/70% in Ⅱa/Ⅱb/Ⅱc/Ⅲa/Ⅲb/Ⅲc, with or without adjuvant chemotherapy at each stage survival rates were compared. In Ⅱa/Ⅱb/Ⅱc, DSS was 97/97/82% and DFS was 89/88/76%, and the prognosis of Ⅱc was significantly worse. In Ⅲa/Ⅲb/Ⅲc, DSS was 95/86/57% and DFS was 82/77/41%. By the presence or absence of adjuvant chemotherapy, significantly differences were obtained at Ⅲb and Ⅲc. Prognosis of Ⅱc was almost same as Ⅲb, and prognosis of Ⅲa was almost same as Ⅱb. Therefore, we considered adjuvant chemotherapy with oxaliplatin should be performed to Ⅱc, Ⅲb, and Ⅲc.