Nomogram-based prognostic stratification for resectable gastric signet-ring cell carcinoma and adenocarcinoma: A retrospective cohort study.

BACKGROUND

Gastric signet-ring cell carcinoma (GSRCC) is a more aggressive subtype of gastric cancer compared to gastric adenocarcinoma (GA), with an increasing incidence. However, the prognostic differences between these subtypes, particularly in resectable cases, remain unclear.

AIM

To evaluate prognostic factors and develop a predictive model for GA and GSRCC patients undergoing curative resection.

METHODS

This retrospective cohort study included patients with GA and GSRCC who underwent curative surgery at the National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences, from 2011 to 2018. Propensity score matching (PSM) (1:1) balanced the baseline characteristics. Prognostic factors were identified using univariate and multivariate Cox and least absolute shrinkage and selection operator (LASSO) regression analyses. Model performance was evaluated through calibration curves, decision curve analysis (DCA), and time-dependent receiver operating characteristic curves. Subgroup analysis and Kaplan-Meier survival curves were generated.

RESULTS

In a cohort of 3027 patients, the GSRCC group was characterized by a significantly higher prevalence of individuals under 60 years of age, females, cases with poor differentiation, and early-stage (stage I) disease (all < 0.001). After PSM, the baseline was balanced and 761 patients were retained in each group. Variables identified through univariate Cox regression were included in the LASSO regression analysis. Multivariate Cox regression analysis identified age, tumor differentiation, tumor size, vascular invasion, and post-treatment nodal margin staging as independent prognostic factors. Subgroup analysis indicated a notably poorer prognosis for GSRCC in patients aged 60 and above (hazard ratio = 1.36, = 0.025). The nomogram (C-index = 0.755) exhibited greater predictive accuracy than tumor node metastasis (TNM) staging for 1-, 3-, and 5-year overall survival (all < 0.001), and provided a higher clinical net benefit according to DCA.

CONCLUSION

This study systematically compared resectable GA and GSRCC, revealing no overall survival difference. However, GSRCC demonstrated a significantly elevated mortality risk in subgroups stratified by age and tumor size. Multivariate analysis identified age, differentiation, tumor size, vascular invasion, and TNM stage as independent prognostic factors. The nomogram integrates clinicopathological features for precise risk stratification, surpassing traditional TNM staging.