Dai Shida1, Yukihide Kanemitsu1, Tetsuya Hamaguchi2, Yasuhiro Shimada3. 1. Colorectal Surgery Division, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo, Japan. 2. Gastrointestinal Medical Oncology Division, Saitama Medical University International Medical Center, Hidaka City, Saitama, Japan. 3. Gastrointestinal Medical Oncology Division, Kochi Health Sciences Center, Kochi City, Kochi, Japan.
Abstract
BACKGROUND: The eighth edition of the tumor-node-metastasis classification of malignant tumors updates cancer staging according to the evidence accumulated in the last 8 years since the release of the tumor-node-metastasis seventh edition. This review focuses on the new staging system. METHODS: The eight edition was compared with the seventh edition as well as the Japanese Classification of Colorcetal, Appendiceal, and Anal carcinoma ninth edition. RESULTS: Of colon and rectum, the tumor-node-metastasis eighth edition expands the M category. Specifically, colorectal cancer with peritoneal metastasis is newly categorized as M1c, distinguishing it from M1a (metastasis to one organ) and M1b (metastasis to more than one organ). In the ninth edition of Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma, M1c is further subdivided into M1c1 (metastasis to the peritoneum without other organ involvement) and M1c2 (metastasis to the peritoneum with other organ involvement). In the T category, the tumor-node-metastasis eighth edition excludes high-grade dysplasia (intraepithelial carcinoma) from Tis; this differs from both the tumor-node-metastasis seventh edition and the Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma ninth edition. In the N category, the tumor-node-metastasis eighth edition does not add the number of tumor deposits to the number of positive regional lymph nodes, whereas this number is added in the Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma ninth edition. The definition of anal cancer is also modified considerably in the tumor-node-metastasis eighth edition; specifically, tumors of perianal skin defined as within 5 cm of the anal margin are also classified as anal canal carcinoma, external iliac lymph nodes become regional lymph nodes, and both N2 and N3 are abolished in the N category. With regard to appendix, Tis (low-grade appendiceal mucinous neoplasma) and tumor deposit(s) are newly introduced. Finally, the tumor-node-metastasis eighth edition offers a new structure, labeled a 'prognostic factors grid', which consists of prognostic factors for survival in both colorectal and anal cancer. CONCLUSIONS: Staging classification is updated regularly, which clinicians should always catch up with.
BACKGROUND: The eighth edition of the tumor-node-metastasis classification of malignant tumors updates cancer staging according to the evidence accumulated in the last 8 years since the release of the tumor-node-metastasis seventh edition. This review focuses on the new staging system. METHODS: The eight edition was compared with the seventh edition as well as the Japanese Classification of Colorcetal, Appendiceal, and Anal carcinoma ninth edition. RESULTS: Of colon and rectum, the tumor-node-metastasis eighth edition expands the M category. Specifically, colorectal cancer with peritoneal metastasis is newly categorized as M1c, distinguishing it from M1a (metastasis to one organ) and M1b (metastasis to more than one organ). In the ninth edition of Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma, M1c is further subdivided into M1c1 (metastasis to the peritoneum without other organ involvement) and M1c2 (metastasis to the peritoneum with other organ involvement). In the T category, the tumor-node-metastasis eighth edition excludes high-grade dysplasia (intraepithelial carcinoma) from Tis; this differs from both the tumor-node-metastasis seventh edition and the Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma ninth edition. In the N category, the tumor-node-metastasis eighth edition does not add the number of tumor deposits to the number of positive regional lymph nodes, whereas this number is added in the Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma ninth edition. The definition of anal cancer is also modified considerably in the tumor-node-metastasis eighth edition; specifically, tumors of perianal skin defined as within 5 cm of the anal margin are also classified as anal canal carcinoma, external iliac lymph nodes become regional lymph nodes, and both N2 and N3 are abolished in the N category. With regard to appendix, Tis (low-grade appendiceal mucinous neoplasma) and tumor deposit(s) are newly introduced. Finally, the tumor-node-metastasis eighth edition offers a new structure, labeled a 'prognostic factors grid', which consists of prognostic factors for survival in both colorectal and anal cancer. CONCLUSIONS: Staging classification is updated regularly, which clinicians should always catch up with.
Authors: Francesco Crafa; Serafino Vanella; Onofrio A Catalano; Kelsey L Pomykala; Mario Baiamonte Journal: World J Gastroenterol Date: 2022-08-14 Impact factor: 5.374