Lin, Jian‐Xian

Background: Due to lacking evidence on surveillance for gastric cancer (GC), this study aimed to determine the optimal postsurgical surveillance strategy for pathological stage (pStage) II/III GC patients and compare its cost-effectiveness with traditional surveillance strategies. Methods: Prospectively collected data from stage II/III GC patients (n=1661) who underwent upfront surgery at a large-volume tertiary cancer center in China (FJMUUH cohort) between January 2010 and October 2015. For external validation, two independent cohorts were included, which were composed of 380 stage II/III GC patients at an tertiary cancer center in U.S.A (Mayo cohort) between July 1991 and July 2012 and 270 stage II/III GC patients at another tertiary cancer center in China (QUAH cohort) between May 2010 and October 2014. Random forest models were used to predict dynamic recurrence hazards and to construct individual surveillance strategies for stage II/III GC. Cost-effectiveness was assessed by the Markov model. Results: The median follow-up period of the FJMUUH, the Mayo, and QUAH cohorts were 55, 158, and 70 months, respectively. In the FJMUUH cohort, the 5-year recurrence risk was higher in pStage III compared with pStage II GC patients (P<0.001). Our novel individual surveillance strategy achieved optimal cost-effectiveness for pStage II GC patients (ICER =$490/QALY). The most intensive NCCN surveillance guideline was more cost-effective (ICER =$983/QALY) for pStage III GC patients. The external validations confirmed our results. Conclusion: For patients with pStage II GC, individualized risk-based surveillance outperformed the JGCTG and NCCN surveillance guidelines. However, the NCCN surveillance guideline may be more suitable for patients with pStage III GC. Even though our results are limited by the retrospective study design, the authors believe that our findings should be considered when recommending postoperative surveillance for stage II/III GC with upfront surgery in the absence of a randomized clinical trial.

AbstractBackgroundThe accuracy of the eighth AJCC ypTNM staging system on the prognosis of gastric cancer (GC) patients after neoadjuvant therapy (NAT) is controversial. This study aimed to develop and validate a novel staging system using the log odds of positive lymph nodes scheme (LODDS).MethodsA retrospective analysis of 606 GC patients who underwent radical gastrectomy after neoadjuvant therapy was conducted as the development cohort. (Fujian Medical University Affiliated Union Hospital (n = 183), Qinghai University Affiliated Hospital (n = 169), Mayo Clinic (n = 236), Lanzhou University First Hospital (n = 18)). The validation cohort came from the SEER database (n = 1701). A novel ypTLoddsS (ypTLM) staging system was established using the 3‐year overall survival. The predictive performance of two systems was compared. ResultsTwo‐step multivariate Cox regression analysis in both cohorts showed that ypTLM was an independent predictor of overall survival of GC patients after neoadjuvant therapy (HR: 1.57, 95% CI: 1.30–1.88, p < 0.001). In the development cohort, ypTLM had better discrimination ability than ypTNM (C‐index: 0.663 vs 0.633, p < 0.001), better prediction homogeneity (LR: 97.7 vs. 70.9), and better prediction accuracy (BIC: 3067.01 vs 3093.82; NRI: 0.36). In the validation cohort, ypTLM had a better prognostic predictive ability (C‐index: 0.614 vs 0.588, p < 0.001; LR: 11,909.05 vs. 11,975.75; BIC: 13,263.71 vs 13,328.24; NRI: 0.22). The time‐dependent ROC curve shows that the predictive performance of ypTLM is better than ypTNM, and the analysis of the decision curve shows that ypTLM achieved better net benefits. ConclusionA LODDS‐based ypTLM staging system based on multicenter data was established and validated. The predictive performance was superior to the eighth AJCC ypTNM staging system.