Decision-making of adjuvant therapy in pT1N1M0 gastric cancer: Should radiotherapy be added to chemotherapy? A propensity score-matched analysis

Abstract

Background: Early gastric cancer (EGC) with metastatic lymph nodes (mLNs) has a relatively higher recurrence rate and poorer prognosis than EGC without mLNs. However, the postoperative treatment directions of pT1N1M0 vary from different guidelines. This study attempted to confirm the value of postoperative treatments in pT1N1M0 GC patients. Methods: Overall, 379 patients with pT1N1M0 GC following gastrectomy from 2000 to 2016 were selected from the Surveillance, Epidemiology, and End Results (SEER) database. Propensity score-matched (PSM) analysis was used to reduce bias. Overall survival was analyzed by Kaplan-Meier method and the log-rank test. Cox proportional hazards regression analyses were used to confirm the independent prognostic factors. Results: Before matching, the results of survival analyses indicated that adjuvant chemotherapy (ACT) and chemoradiotherapy (ACRT) could significantly prolong the survival time of the cohort (P < 0.05). After PSM analysis, 136 patients remained and ACRT maintained significance in the survival analysis (P = 0.018). Furthermore, patients with well or moderately differentiated GC (HR = 0.226, P =0.018) or intestinal type GC (HR = 0.380, P = 0.040) achieved a significantly superior prognosis with ACRT, compared to patients receiving ACT. Conclusion: The survival benefit of ACRT and ACT for pT1N1M0 GC patients following gastrectomy was confirmed in the SEER cohort. RT added to ACT might be recommended according to Lauren's classification and tumor grade in clinical decision making.

Adjuvant Therapy Improves Survival in T1N1M0 Gastric Cancer Patients with Poorly Differentiated and Undifferentiated Types

“…It showed that highly differentiated or gastrointestinal type gastric cancer patients derived signi cant bene t from adjuvant therapy, while poorly differentiated and undifferentiated types did not, which contradicts our ndings. 23 However, this study had a small sample size of only 106 patients after matching, with only 71 of them being undifferentiated or poorly differentiated, which may have limited its statistical power and led to opposing conclusions.Another study using the NCDB database focused on stage IB patients and concluded that adjuvant therapy did not bene t them. However, their multivariate Cox regression analysis revealed that poorly differentiated signi cantly in uenced patient prognosis compared to highly differentiated gastric cancer.…”

“…Secondly, all patients in the ACTSGC trial and underwent D2 gastrectomy in Japan, while D0 or D1 gastrectomy remained the standard procedure in the USA during the same period. 23 However, a study using the SEER database included 379 patients from 2000-2016. It showed that highly differentiated or gastrointestinal type gastric cancer patients derived signi cant bene t from adjuvant therapy, while poorly differentiated and undifferentiated types did not, which contradicts our ndings.…”

A Novel Method for Dynamically Assessing the Prognosis of Patients with pT1 Gastric Cancer: A Large Population-Based Dynamic Prognostic Analysis

“…In prior studies, metastatic LNs have been reported in over 47% of individuals with EGC [10][11][12]. Age, tumor size, Lauren's classifcation, and other factors have also been associated with EGC patients' prognosis and postoperative treatment selection [8,[13][14][15][16]. For EGC, the favorable prognosis may only apply to patients with pT1aN0M0 GC, while for the other types of EGC, maintaining the traditional perception may have a negative impact on clinical decision-making and the formulation of follow-up schemes.…”