Objective To investigate the impact of pathological response to neoadjuvant therapy on survival benefit of postoperative adjuvant therapy in gastric cancer.
Methods The retro-spective cohort study was conducted. The clinicopathological data of 503 patients with gastric cancer who underwent radical resection after adjuvant therapy at Peking University Cancer Hospital between January 2013 and December 2023 were collected. There were 366 males and 137 females, aged 60 (53, 66) years. All the 503 patients underwent radical gastrectomy after neoadjuvant therapy. Observational indicators: (1) treatment status; (2) analysis of factors associated with patient survival; (3) comparison of clinicopathological characteristics among patients with different types of patholo-gical response; (4) follow‑up. Comparison of measurement data with normal distribution between groups was conducted using the independent sample t test. Comparison of measurement data with skewed distribution between groups was conducted using the Mann‑Whitney U test. Comparison of count data between groups was conducted using the chi‑square test or Fisher exact probability. The Kaplan‑Meier method was used to draw survival curves and Log‑rank test was used for survival analysis. Univariate analysis was conducted using corresponding statistical methods based on the data type, and multivariate analysis was performed using Cox regression analysis. Clinicopathological variables with P<0.10 in univariate analysis and with clinical value were included in the multivariate analysis.
Results (1)Treatment status: of the 503 patients, 381 cases received neoadjuvant chemotherapy, 113 cases received neoadjuvant chemotherapy combined with other therapies, 8 cases received neoadjuvant immunotherapy, and 1 case received neoadjuvant targeted therapy. The treatment cycles were 3 (3, 4). Of the 503 patients, 280 cases did not receive postoperative adjuvant therapy, while 223 cases received postoperative adjuvant therapy, including 119 cases receiving adjuvant chemotherapy, 21 cases receiving adjuvant chemotherapy combined with other therapies, 1 case receiving adjuvant radiotherapy, and 1 case receiving adjuvant immunotherapy. The cycles of postoperative adjuvant treatment in the 223 patients were 5 (3, 5). There were significant differences in age, tumor location, year of surgery, and pathological response type between the 223 patients receiving post-operative adjuvant therapy and 280 patients not receiving postoperative adjuvant therapy (U=36 009.50, χ²=9.42, 47.66, Z=-2.81, P<0.05). (2) Analysis of factors associated with patient survival: results of multivariate analysis showed that partial pathological response and no pathological response were independent influencing factors for prognosis in patients undergoing radical gastrectomy for gastric cancer (hazard ratio=5.70, 5.37, 95% confidence interval as 2.08-15.65, 1.92-15.05, P<0.05). (3) Comparison of clinical characteristics among patients with different types of pathological response: among the 142 patients with no pathological response, there was a significant difference in the year of surgery between the 71 cases receiving postoperative adjuvant therapy and 71 cases not receiving postoperative adjuvant therapy (χ²=4.06, P<0.05). Among the 282 patients with partial pathological response, there were significant difference in the age, tumor location, and year of surgery between the 130 cases receiving postoperative adjuvant therapy and 152 cases not receiving postoperative adjuvant therapy (U=11 774.00, χ²=4.49, 35.47, P<0.05). Among the 79 patients with complete patho-logical response, there were significant difference in the age and year of surgery between the 22 cases receiving postoperative adjuvant therapy and 57 cases not receiving postoperative adjuvant therapy (χ²=4.12, 6.00, P<0.05). (4) Follow‑up: all 503 patients were followed up for 38 (20, 75) months. Results of multivariate analysis showed that among the 142 patients with no pathological response, there was no significant difference in the overall survival time between the 71 cases receiving postoperative adjuvant therapy and 71 cases not receiving postoperative adjuvant therapy (hazard ratio=0.91,95% confidence interval as 0.49-1.70, P>0.05). Among the 282 patients with partial pathological response, there was a significant difference in the overall survival time between the 130 cases receiving postoperative adjuvant therapy and 152 cases not receiving postoperative adjuvant therapy (hazard ratio=0.60, 95% confidence interval as 0.37-0.96, P<0.05).
Conclusions Partial pathological response and no pathological response are independent influencing factors for prognosis in patients undergoing radical gastrectomy for gastric cancer. Among patients with gastric cancer who underwent radical gastrectomy after neoadjuvant therapy, those with partial pathological response may derive a survival benefit from postoperative adjuvant therapy. In contrast, patients with no pathological response did not appear to gain a significant survival benefit from postoperative adjuvant therapy.
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