Prognostic Impact of Tumor Growth Rate During Second-line Chemotherapy in Patients With Gastric Cancer.

Background/Aim: Despite the remarkable developments in chemotherapy for gastric cancer (GC), rapid tumor growth is sometimes experienced during chemotherapy. This study investigated the association of tumor growth rate (TGR) during second-line chemotherapy with the prognosis of patients with GC. Patients and Methods: We retrospectively reviewed 29 patients with GC treated with nab-paclitaxel plus ramucirumab as second-line chemotherapy between 2017 and 2019 at Osaka Metropolitan University. Of them, 13 cases with target lesions were classified into two groups according to TGR using a cutoff value of 0.25. Clinicopathological factors and survival outcomes were compared between the high TGR (n=5) and low TGR (n=8) groups. Results: The median duration of first-line chemotherapy was significantly longer in the high TGR group than in the low TGR group [median 298 days vs. 72.5 days, p=0.030]. Progressive disease (PD) was observed in 60% of patients with high TGR, whereas stable disease (SD) was observed in 75% patients with low TGR. The median survival time (MST) after starting chemotherapy was 488 days in the low TGR group but was not reached in the high TGR group (log rank p=0.215). The MST after PD was 145 days in the low TGR group but was not estimated in the high TGR group (log rank p=0.345). Conclusion: Based on the absence of significant differences in survival outcomes between the high and low TGR groups, sequential late-line chemotherapy might be considered important, even for patients with high TGR.