Long-term prognostic benefit of adjuvant chemotherapy for patients with hepatoid adenocarcinoma of the stomach after radical resection: A national multicenter study

Background There is no consensus on whether adjuvant chemotherapy (AC) is effective for hepatoid adenocarcinoma of the stomach (HAS). The aim of this study was to investigate the relationship between AC and the long-term prognosis of patients with HAS. Methods The clinicopathological data of 239 patients with primary HAS who underwent radical surgery from April 1, 2004 to December 31, 2019 in 14 centers in China were retrospectively analyzed. Patients were divided into the AC group (127 patients) and the nonadjuvant chemotherapy (NAC) group (112 patients). Results Kaplan‒Meier (KM) analysis showed that there were no significant differences in the 1-year overall survival rate (OS) and 3-year recurrence-free survival rate (RFS) between the AC group and the NAC group (1-year OS: 85.6% vs. 79.8%, 3-year OS: 59.8% vs. 62.4%, 1-year RFS: 69.8% vs. 74.4%, 3-year RFS: 57.2% vs. 55.9%, all P > 0.05). The subpopulation treatment effect pattern plots (STEPP) did not show treatment heterogeneity of AC in patients with HAS. The proportions of local recurrence and metastasis sites in the two groups were similar. Although the smoothed hazard curves of the NAC and AC groups crossed, the peak hazard time was later in the AC group (5.9 and 4.7 months), and the peak hazard rate was lower (0.032 and 0.038, P = 0.987). Conclusion The current AC regimen may not significantly improve the survival of patients with HAS after radical surgery.