2125 Evaluation timing and cutoff value of tumor size (TS) ratio by using tumor growth inhibition (TGI) model to predict overall survival (OS) in metastatic colorectal cancer (mCRC) patients received first-line chemotherapy (CTx). (September 2015) - Kito, Y.; Sakamaki, K.; Yamazaki, K.; Izawa, N.; Tsuda, T.; Morita, S.; Boku, N.