The phase III WJOG4407G study showed non-inferiority of FOLFIRI plus bevacizumab to mFOLFOX6 plus bevacizumab in progression-free survival, as the first-line chemotherapy for patients with metastatic colorectal cancer. The aim of this study was to evaluate the predictive and prognostic value of morphologic response to first-line chemotherapy containing bevacizumab in patients with CLM.
This study is a post hoc analysis of patients from the WJOG4407G study. Morphologic response was assessed with the comparison of baseline and week 8 contrast-enhanced CT images. Three blinded radiologists evaluated CT images and classified as optimal, incomplete or none response according to the morphologic criteria. RECIST response, early tumor shrinkage (ETS) and depth of response (DpR) were also evaluated. The Cox proportional hazards model was used to investigate the association between radiological variables and progression-free survival (PFS) and overall survival (OS).
Of 395 patients who were eligible for efficacy analysis in the WJOG4407G study, 70 patients had liver-limited disease. Enhanced CT images of 57 of these patients from 22 participating centers were collected. Two patients were excluded from this analysis because their post-chemotherapy metastases were too small. Optimal morphologic response was identified in 19 of 55 patients (34.5%). The median PFS was 10.7 months for patients with optimal response and 10.1 months in those with incomplete/no response (log-rank p = 0.96). The median OS was 26.2 and 35.5 months, respectively (log-rank p = 0.062). According to univariate analysis, morphologic response was not associated with PFS or OS, whereas RECIST response was significantly associated with both PFS and OS, with ETS and DpR being associated with significantly longer PFS.
Morphologic response might be neither predictive nor prognostic factor in patients with CLM undergoing chemotherapy containing bevacizumab, whereas RECIST response was significantly associated with both PFS and OS.
Clinical trial identification
Legal entity responsible for the study
West Japan Oncology Group.
West Japan Oncology Group.
A. Hosokawa: Honoraria: Taiho, Chugai, Takeda, Ono, Novartis, Eisai, Eli Lilly; Research funding: Taiho, Chugai, Ono, Eisai, Yakult. K. Yamazaki: Speakers’ bureau: Chugai, Takeda, Taiho, Yakult, Merck Serono, Eli Lilly, Sanofi, Bayer E. Baba: Speakers’ bureau: Chugai, Eli Lilly; Research funding: Ono, Chugai, Eli Lilly, Takeda, Taiho, Merck Serono. K. Shinozaki: Honoraria: Chugai, Takeda, Mochida, Merck Serono, Taiho, Yakult, Astellas, Novartis, Eisai, Eli Lilly, Shionogi, Kyowa Hakko Kirin, Asahi Kasei, MSD. S. Morita: Honoraria: Chugai Pharma, Daiichi Sankyo. K. Muro: Honoraria: Chugai, Taiho, Bayer, Ono, Eli Lilly, Takeda; Research funding: Ono, MSD, Daiichi Sankyo, Kyowa Hakko Kirin, Gilead Sciences, Shionogi. All other authors have declared no conflicts of interest.