Novel Prognostic Nomogram for Recurrence-Free Survival of Patients With Primary Gastrointestinal Stromal Tumors After Surgical Resection: Combination of Prognostic Nutritional Index and Basic Variables.

Background: Gastrointestinal stromal tumor (GIST) is the most common type of mesenchymal tumors in the digestive tract, often recrudescing even after R0 resection. Adjuvant tyrosine kinase inhibitor therapy prolonged recurrence-free survival (RFS). This study aimed to develop a novel nomogram for predicting the RFS of patients following surgical resection of GISTs.

Methods: Clinicopathologic data of patients with GISTs at Tianjin Medical University General Hospital (Tianjin, China) from January 2000 to October 2019 were retrospectively reviewed. Univariate and multivariate Cox regression analyses were used to select the suitable variables from the training cohort to construct a nomogram for 2- and 5-year RFS. The 1,000 bootstrap samples and calibration curves were used to validate the discrimination of the nomogram. The receiver operating characteristic analysis(ROC) was used to compare the predictive ability of the nomogram and present four commonly used risk stratification systems: National Institutes of Health (NIH)-Fletcher staging system; NIH-Miettinen criteria; Modified NIH criteria; and Air Forces Institute of Pathology risk criteria (AFIP).

Results: Univariate and multivariate analyses showed that the tumor site, tumor size, mitotic index, tumor rupture, and prognostic nutritional index were significant factors associated with RFS. These variables were selected to create the nomogram for 2- and 5-year RFS (all <0.05). The 2- and 5-year the ROC of the nomogram were 0.821 (95% confidence interval [CI]: 0.740-0.903) and 0.798 (95% CI: 0.739-0.903); NIH-Fletcher criteria were 0.757 (95% CI: 0.667-0.846) and 0.683 (95% CI: 0.613-0.753); NIH-Miettinen criteria were 0.762 (95% CI: 0.678-0.845) and 0.718 (95% CI: 0.653-0.783); Modified NIH criteria were 0.750 (95% CI: 0.661-0.838) and 0.689 (95% CI: 0.619-0.760); and AFIP were 0.777 (95% CI: 0.685-0.869) and 0.708 (95% CI: 0.636-0.780). Hence, the predictive probabilities of our nomogram are better than those of other GIST risk stratification systems.

Conclusion: This nomogram, combining tumor site, tumor size, mitotic index, tumor rupture, and prognostic nutritional index, may assist physicians in providing individualized treatment and surveillance protocols for patients with GISTs following surgical resection.