# Impact of gastrectomy on efficacy and safety of second‐line chemotherapy patients with advanced gastric cancer: Exploratory analysis of two randomized phase III trials

## TL;DR

Patients who had prior gastrectomy had better survival outcomes with second-line chemotherapy for advanced gastric cancer compared to those without prior surgery.

## Contribution

This study is the first to show that prior gastrectomy improves survival outcomes in second-line chemotherapy for advanced gastric cancer.

## Key findings

- Patients with prior gastrectomy had significantly better overall and progression-free survival.
- Adjusted survival outcomes remained better for patients with prior gastrectomy after accounting for background factors.
- No significant differences in response rates or severe adverse events were observed between the groups.

## Abstract

Second‐line chemotherapy (SLC) improves survival in advanced gastric cancer (AGC). Although many patients receiving SLC have undergone gastrectomy, the impact of gastrectomy on SLC remains unclear.

The objective was to evaluate the impact of gastrectomy on SLC for AGC. A total of 290 eligible patients registered in two randomized phase III trials evaluating SLC for patients with AGC was classified into the prior gastrectomy group (PGG; n = 187) or the no gastrectomy group (NGG; n = 103). We compared overall survival (OS), progression‐free survival (PFS), overall response rate (ORR), disease control rate (DCR), and safety between these two groups. Adjusted OS and adjusted PFS were estimated using inverse probability of treatment weighting (IPTW).

The PGG had better performance status (p = 0.001), more prior platinum agent (p < 0.001), and more frequent peritoneal metastasis (p = 0.006) than the NGG. The PGG had significantly better OS (13.8 vs. 9.3 mo; hazard ratio [HR]: 0.59; p < 0.001) and PFS (4.7 vs. 2.8 mo; HR: 0.58; p < 0.001) than the NGG. The PGG had significantly better adjusted OS (13.8 vs. 10.0 mo; IPTW HR: 0.66; p = 0.01) and adjusted PFS (4.3 vs. 3.2 mo; IPTW HR: 0.71; p = 0.027) than the NGG. No significant differences were observed in ORR and DCR. The incidence of Grade 3 or worse adverse events did not differ between the two groups except for a high incidence of anemia and diarrhea in the NGG.

Patients with previous gastrectomy are expected to have better survival outcomes when receiving second‐line irinotecan (IRI)‐based chemotherapy for AGC.

In an analysis of two RCTs of IRI‐based second‐line chemotherapy for AGC, patients with prior gastrectomy had better OS and PFS than patients without prior gastrectomy. Furthermore, patients with prior gastrectomy had a better prognosis in OS and PFS adjusted for background factors as well.