Comparison of the safety and efficacy of different neoadjuvant therapy cycles for locally advanced gastric cancer: a retrospective propensity score-matched cohort study.

BACKGROUND: For locally advanced gastric cancer (LAGC), neoadjuvant therapy prior to radical gastrectomy has been widely used. However, the treatment cycle and factors affecting the efficacy of neoadjuvant therapy are still unclear. METHODS: This study analysed LAGC patients who underwent radical gastrectomy after different neoadjuvant therapy cycles at the Qilu Hospital of Shandong University between October 2016 and July 2024. 221 patients were enrolled in the study. After propensity score matching (PSM), baseline data, surgical and pathological features, surgical safety and postoperative recovery, tumor regression grade (TRG) and cumulative survival analysis were compared between the different neoadjuvant therapy cycle groups, and prognostic risk factors for overall survival (OS) were explored. RESULTS: There was no statistically significant difference in survival between the different neoadjuvant therapy cycle groups before and after PSM (P > 0.05). Multivariate Cox regression analysis revealed that TRG > 1 (HR = 1.767, 95% CI: 1.055–2.957, P = 0.03) was an independent prognostic risk factor for OS. Furthermore, multivariate logistic regression analysis revealed that neoadjuvant therapy regimen (neoadjuvant chemotherapy alone) (OR = 4.555, 95% CI: 2.159–9.613, P < 0.001), histopathological type (others) (OR = 6.514, 95% CI: 1.429–29.688, P = 0.015) and tumor size (≥ 5 cm) (OR = 4.059, 95% CI: 1.842–8.944, P < 0.001) were independent risk factors for TRG ≤ 1. CONCLUSION: The number of cycles of neoadjuvant therapy has no significant impact on TRG and OS. TRG > 1 is an independent prognostic risk factor, and patients with better tumor regression have a better prognosis. The neoadjuvant therapy regimen, histopathological type and tumor size can affect TRG.