Three-year outcomes of the randomized phase III SEIPLUS trial of extensive intraoperative peritoneal lavage for locally advanced gastric cancer

Abstract

Whether extensive intraoperative peritoneal lavage (EIPL) after gastrectomy is beneficial to patients with locally advanced gastric cancer (AGC) is not clear. This phase 3, multicenter, parallel-group, prospective randomized study (NCT02745509) recruits patients between April 2016 and November 2017. Eligible patients who had been histologically proven AGC with T3/4NxM0 stage are randomly assigned (1:1) to either surgery alone or surgery plus EIPL. The results of the two groups are analyzed in the intent-to-treat population. A total of 662 patients with AGC (329 patients in the surgery alone group, and 333 in the surgery plus EIPL group) are included in the study. The primary endpoint is 3-year overall survival (OS). The secondary endpoints include 3-year disease free survival (DFS), 3-year peritoneal recurrence-free survival (reported in this manuscript) and 30-day postoperative complication and mortality (previously reported). The trial meets pre-specified endpoints. Estimated 3-year OS rates are 68.5% in the surgery alone group and 70.6% in the surgery plus EIPL group (log-rank p = 0.77). 3-year DFS rates are 61.2% in the surgery alone group and 66.0% in the surgery plus EIPL group (log-rank p = 0.24). The pattern of disease recurrence is similar in the two groups. In conclusion, EIPL does not improve the 3-year survival rate in AGC patients.

Conflict of interest statement

The authors declare no competing interests.

© 2021. The Author(s).

Figures

Fig. 1. Trial CONSORT flow diagram.

EIPL extensive intraoperative peritoneal lavage.

Fig. 2. Kaplan–Meier estimates of survival curves for the surgery alone and surgery+EIPL groups.

Kaplan–Meier estimates of overall survival (a), disease-free survival (b), and peritoneal recurrence-free survival (c) in all randomized patients by treatment group. Log-rank test was used to compare both curves. EIPL extensive intraoperative peritoneal lavage.

Fig. 3. Subgroup analyses.

a Subgroup analyses of overall survival according to the clinicopathological characteristics of the patients (n = 662). Data are plotted as HR value (red squares) with the corresponding two-sided 95% CI (error bars) based on the Cox regression method. b, c Kaplan–Meier estimates of overall survival (b) and disease-free survival (c) in stage N1 patients by treatment group. Log-rank test was used to compare both curves. EIPL extensive intraoperative peritoneal lavage, OS overall survival, HR hazard ratio, 95% CI 95% confidence interval, BMI body mass index.