Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma: the 3d English Edition [Secondary Publication]

Abstract

Based on literature evidence and expert consensus, the Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma1,2) (JCCRC) has been developed and sustained by the Japanese Society for Cancer of the Colon and Rectum (JSCCR) since 1977. Through defining detailed rules for evaluating and documenting clinical and pathological findings, and handling specimens of colorectal cancer, the JCCRC has contributed to the standardization and improvement of the diagnosis and treatment of colorectal cancer in Japan. Furthermore, the JSCCR guidelines for colorectal cancer treatment3), which have been revised several times since the first edition was issued in 2005, describe treatment algorithms conforming to the JCCRC; therefore, its importance is continuing to increase. Under these circumstances, the revisions have to maintain the classification’s role to further improve treatment outcomes for colorectal cancer in Japan, which are already among the best in the world. At the same time, there is a focus on harmonizing with the eighth edition of the TNM classification4) and classification of cancers in other organs in Japan. Stage grouping of colorectal cancer was compromised with that of the TNM classification. However, some differences were caused by the classification of lymph node metastasis. Expertise built up over several years emphasizes the importance of the main and lateral lymph nodes (N3) in Japan. Further, the definition of “extramural cancer deposits without lymph node structure (EX)” differs from that of “tumor deposits” in the TNM classifications. Meanwhile, because of the low prevalence of appendiceal and anal cancers arising from the anoderm in Japan, the current edition incorporates the TNM classification in these clinical entities.