Identifying beneficial gastric cancer patient on prognosis after treating with perioperative or postoperative-only chemotherapy: a single-center real-world study.

BACKGROUND

This study evaluates the impact of perioperative S-1 and oxaliplatin (SOX) versus postoperative SOX or capecitabine and oxaliplatin (XELOX) on patient prognosis to identify suitable candidates for each therapy.

METHOD

A retrospective real-world cohort study was conducted using data from Zhejiang Cancer Hospital on gastric cancer patients treated between 2010 and 2019. Patients were divided into perioperative SOX and postoperative SOX or XELOX groups. Propensity score matching (PSM) was used to control for selection bias. Overall survival (OS) was the primary outcome, analyzed using the Kaplan-Meier method and Cox regression.

RESULT

A total of 816 patients were included: 293 in the perioperative SOX group and 523 in the postoperative chemotherapy group (408 SOX and 115 XELOX). In the perioperative SOX group, the tumor regression grade (TRG) 2-3 subgroup demonstrated a significantly worse overall survival (OS) compared to the postoperative XELOX group (95% CI = 1.064-3.444, P = 0.027). Subgroup analysis revealed that older patients (95% CI = 0.210-0.950, P = 0.036), and those at the cT3 (95% CI = 0.05-1.19, P = 0.008) stage experienced greater benefits from postoperative chemotherapy. When comparing the benefited populations, it was found that patients with CA125 positivity had an advantage trend with adjuvant chemotherapy compared to perioperative SOX chemotherapy.

CONCLUSION

Real-world data suggest that perioperative SOX chemotherapy does not benefit all patients with advanced gastric cancer. Patients with TRG 2-3, older age, or cT3 stage may achieve better outcomes with postoperative chemotherapy. Additionally, an exploratory analysis indicated that CA125 positivity may be associated with improved survival following adjuvant treatment.