Shuhei Mayanagi, Junichi Sakamoto, Koji Oba, Chikuma Hamada, Shigetoyo Saji, Toru Aoyama, Masashi Ueno, Takashi Akiyoshi, Takaki Yoshikawa, Mitsuro Kanda, Kosuke Kashiwabara, Yosuke Fukunaga, Michitaka Honda, Sotaro Sadahiro, and Hiromichi Maeda
// Michitaka Honda 1, * , Koji Oba 2, * , Takashi Akiyoshi 3 , Hiromichi Maeda 4 , Kosuke Kashiwabara 2 , Mitsuro Kanda 5 , Shuhei Mayanagi 6 , Toru Aoyama 7 , Chikuma Hamada 8 , Sotaro Sadahiro 9 , Yosuke Fukunaga 3 , Masashi Ueno 3 , Junichi Sakamoto 10, 11 , Shigetoyo Saji 11 and Takaki Yoshikawa 12 1 Department of Minimally Invasive Surgical and Medical Oncology, Fukushima Medical University, Fukushima, Japan 2 Department of Biostatistics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan 3 Department of Gastroenterological Surgery, Gastroenterological Center, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan 4 Cancer Treatment Center, Kochi Medical School Hospital, Kochi University, Nankoku, Japan 5 Department of Gastroenterological Surgery (Surgery II), Nagoya University Graduate School of Medicine, Nagoya, Japan 6 Department of Surgery, Keio University, Tokyo, Japan 7 Department of Surgery, Yokohama City University, Yokohama, Japan 8 Faculty of Engineering, Tokyo University of Science, Tokyo, Japan 9 Department of Surgery, Tokai University, Isehara, Japan 10 Tokai Central Hospital, Kakamigahara, Japan 11 Japanese Foundation for Multidisciplinary Treatment of Cancer, Tokyo, Japan 12 Department of Gastrointestinal Surgery, Kanagawa Cancer Center, Yokohama, Japan * These authors contributed equally to this work Correspondence to: Michitaka Honda, email: mhonda@fukushimamed.com Takaki Yoshikawa, email: yoshikawat@kcch.jp Keywords: prognostic nomogram, prediction model, colorectal cancer, overall survival, disease free survival Received: August 14, 2017 Accepted: September 21, 2017 Published: October 12, 2017 ABSTRACT Background: Few prediction models have so far been developed and assessed for the prognosis of patients who undergo curative resection for colorectal cancer (CRC). Materials and Methods: We prepared a clinical dataset including 5,530 patients who participated in three major randomized controlled trials as a training dataset and 2,263 consecutive patients who were treated at a cancer-specialized hospital as a validation dataset. All subjects underwent radical resection for CRC which was histologically diagnosed to be adenocarcinoma. The main outcomes that were predicted were the overall survival (OS) and disease free survival (DFS). The identification of the variables in this nomogram was based on a Cox regression analysis and the model performance was evaluated by Harrell’s c-index. The calibration plot and its slope were also studied. For the external validation assessment, risk group stratification was employed. Results: The multivariate Cox model identified variables; sex, age, pathological T and N factor, tumor location, size, lymphnode dissection, postoperative complications and adjuvant chemotherapy. The c-index was 0.72 (95% confidence interval [CI] 0.66-0.77) for the OS and 0.74 (95% CI 0.69-0.78) for the DFS. The proposed stratification in the risk groups demonstrated a significant distinction between the Kaplan–Meier curves for OS and DFS in the external validation dataset. Conclusions: We established a clinically reliable nomogram to predict the OS and DFS in patients with CRC using large scale and reliable independent patient data from phase III randomized controlled trials. The external validity was also confirmed on the practical dataset.