Research Appraisalobservational

Machine Learning-Based Survival Prediction Models for Young Patients With Gastric Cancer: Model Development and Validation Study

JMIR cancerKang, Ha Ye Jin, Jang, Wooyeong, Ko, Minsam et al.26 May 2026DOI

Clinical Snapshot

60CEBM
Evidence: Weakobservational

PICO Framework

P — PopulationYoung patients (≤50 years) diagnosed with gastric cancer between 2013-2015 (n=813)
I — InterventionMachine learning-based survival prediction models (random survival forest, gradient boosting survival analysis, extra survival tree)
C — ComparatorCox proportional hazards model
O — Outcomes3-year and 5-year survival prediction accuracy measured by concordance index (C-index)

Bottom Line

This study developed machine learning models for predicting 3- and 5-year survival in young gastric cancer patients, achieving high discrimination performance (C-index >90% for most models). While the technical performance appears impressive, the clinical utility remains uncertain due to lack of external validation, missing follow-up data, and absence of comparison with existing prognostic tools. The study identifies tumor stage and size as key predictive factors, consistent with established prognostic knowledge. Before clinical implementation, external validation in independent cohorts is essential, along with assessment of clinical utility through decision curve analysis. The models may eventually help identify high-risk young patients who could benefit from more aggressive treatment strategies, but current evidence is insufficient to recommend routine clinical use.

Evidence: Weak

Key Findings

  • P Value: Not reported

  • Effect Size: C-index ranging from 82.26% to 95.89% across different models and time points

  • Primary Outcome: Survival prediction accuracy at 3 and 5 years

  • Nnt Or Sensitivity: Random survival forest achieved highest C-index: 95.89% (3-year) and 91.82% (5-year)

  • Confidence Interval: 95% CI ranges from 89.95%-95.97% depending on model

Clinical Application

Requires implementation of machine learning infrastructure and access to comprehensive staging data Relevant for Australian oncology practice given similar gastric cancer epidemiology, though external validation needed in Australian cohorts. Could inform PBS funding decisions for intensive treatments in high-risk young patients Young patients (≤50 years) with gastric cancer requiring prognostic assessment

Abstract

BACKGROUND: Despite a global decline in the incidence of gastric cancer (GC), the number of cases diagnosed among younger individuals continues to increase. Several studies have been conducted to develop predictive models of mortality in patients with GC. OBJECTIVE: We developed 3- and 5-year survival prediction models for young patients with GC based on machine learning-based survival modeling approaches. METHODS: Data from 813 young patients (≤50 years) diagnosed with GC between 2013 and 2015 were retrieved from the Gastric Cancer Public Staging Database. Among these 813 patients, data from 569 (70%) and 244 (30%) were allocated to the model training and testing datasets, respectively. Random survival forest, gradient boosting survival analysis, extra survival tree, and the Cox proportional hazards model were applied to predict survival outcomes at the 3- and 5-year time horizons. Model performance was assessed and quantified using the concordance index (C-index) metric. For the machine learning prediction models, the mean C-index values and corresponding 95% CIs were estimated across 100 repeated training iterations. RESULTS: For the random survival forest model, the C-index for predicting 3-year mortality was 95.89% (95% CI 95.80%-95.97%), whereas the C-index for predicting 5-year mortality was 91.82% (95% CI 91.68%-91.96%). In the gradient boosting survival analysis model, the C-index for predicting 3-year mortality was 95.32% (95% CI 95.31%-95.33%), and the C-index for predicting 5-year mortality was 89.98% (95% CI 89.95%-90.01%). For the extra survival tree model, the C-index for predicting 3-year mortality was 95.53% (95% CI 95.46%-95.60%), whereas the C-index for predicting 5-year mortality was 94.60% (95% CI 94.50%-94.70%). In addition, the Cox proportional hazards model showed a C-index of 94.15% for predicting 3-year mortality and 82.26% for predicting 5-year mortality. Tumor stage and tumor size were the primary predictive variables used to train the models for mortality prediction at different time points. Other variables exhibited varying levels of predictive contribution across different time points. CONCLUSIONS: These findings may facilitate the identification of high-risk young patients with GC who may benefit from more aggressive treatment strategies by enabling the prediction of mortality risk at different time points.

References

  1. 1.Kang, H. Y. J., Jang, W., Ko, M., & Ryu, K. S. (2026). Machine Learning-Based Survival Prediction Models for Young Patients With Gastric Cancer: Model Development and Validation Study. JMIR Cancer. https://doi.org/10.2196/86418
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