Kei Kitamura1, Dai Shida2,3, Shigeki Sekine4, Yuka Ahiko1,5, Yuya Nakamura1, Konosuke Moritani1, Shunsuke Tsukamoto1, Yukihide Kanemitsu1. 1. Department of Colorectal Surgery, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045, Japan. 2. Department of Colorectal Surgery, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045, Japan. dshida@g.ecc.u-tokyo.ac.jp. 3. Division of Frontier Surgery, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-8639, Japan. dshida@g.ecc.u-tokyo.ac.jp. 4. Molecular Pathology Division, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045, Japan. 5. Division of Frontier Surgery, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-8639, Japan.
Abstract
BACKGROUND: The most widely accepted staging system for colorectal cancer (CRC) is the tumor-node-metastasis (TNM) classification. In Japan, the Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma (JCCRC) system is used. The two systems differ mainly in relation to tumor deposits (TD) and metastasis in the regional lymph nodes along the main feeding arteries and lateral pelvic lymph nodes (N3). Here, we investigated the prognostic ability of the two systems for stage III CRC. METHODS: We reviewed 696 consecutive patients who underwent curative resection of stage III CRC at the National Cancer Center Hospital between May 2007 and April 2014. We examined the clinicopathological features of CRC and predicted overall survival (OS) and relapse-free survival (RFS) according to the 8th TNM and 9th JCCRC systems. The systems were compared using Akaike's information criterion (AIC), Harrell's concordance index (C-index), and time-dependent receiver-operating characteristic (ROC) curves. RESULTS: The 9th JCCRC system was more clinically effective according to AIC (OS, 1199 vs. 1206; RFS, 2047 vs. 2057), showed better discriminatory ability according to the C-index (OS, 0.65 vs. 0.62; RFS, 0.62 vs. 0.58), and its time-dependent ROC curve was superior compared with the 8th TNM system. CONCLUSION: These results suggest that the 9th JCCRC system has superior discriminative ability to the 8th TNM system, because the 9th JCCRC accounts for the presence of TD and N3 disease, which were both significant predictors of poor prognosis. Reconsidering the clinical value of these two factors in the TNM system could improve its clinical significance.
BACKGROUND: The most widely accepted staging system for colorectal cancer (CRC) is the tumor-node-metastasis (TNM) classification. In Japan, the Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma (JCCRC) system is used. The two systems differ mainly in relation to tumor deposits (TD) and metastasis in the regional lymph nodes along the main feeding arteries and lateral pelvic lymph nodes (N3). Here, we investigated the prognostic ability of the two systems for stage III CRC. METHODS: We reviewed 696 consecutive patients who underwent curative resection of stage III CRC at the National Cancer Center Hospital between May 2007 and April 2014. We examined the clinicopathological features of CRC and predicted overall survival (OS) and relapse-free survival (RFS) according to the 8th TNM and 9th JCCRC systems. The systems were compared using Akaike's information criterion (AIC), Harrell's concordance index (C-index), and time-dependent receiver-operating characteristic (ROC) curves. RESULTS: The 9th JCCRC system was more clinically effective according to AIC (OS, 1199 vs. 1206; RFS, 2047 vs. 2057), showed better discriminatory ability according to the C-index (OS, 0.65 vs. 0.62; RFS, 0.62 vs. 0.58), and its time-dependent ROC curve was superior compared with the 8th TNM system. CONCLUSION: These results suggest that the 9th JCCRC system has superior discriminative ability to the 8th TNM system, because the 9th JCCRC accounts for the presence of TD and N3 disease, which were both significant predictors of poor prognosis. Reconsidering the clinical value of these two factors in the TNM system could improve its clinical significance.