Reassessment of the recurrence risk of primary gastrointestinal stromal tumour after complete resection

The modified National Institutes of Health (NIH) risk criteria for gastrointestinal stromal tumours (GISTs) have some limitations and need to be improved.Patients who underwent radical resection of primary GIST were retrospectively reviewed. Peripheral blood indices including the neutrophil-to-lymphocyte ratio (NLR) and prognostic nutritional index (PNI) were analysed. Recurrence-free survival (RFS) was calculated and compared. Multivariate analysis was conducted. Area under the receiver operating characteristic curve (ROC) was calculated.A total of 492 patients were enrolled. Tumour size, mitotic index (MI), tumour location and PNI were independent prognostic factors. The modified NIH criteria could not distinguish among very low-, low- and intermediate-risk patients, and PNI was the only independent prognostic factors for them. The five-year RFS rate in the high risk (HR) group was significantly lower. A further modification to the NIH risk criteria was proposed (the 'NIH-PNI stratification'). Non-high risk (NHR) patients were divided into the NHR-PNI-H group (PNI > 48.05) and the NHR-PNI-L group (PNI ≤ 48.05), respectively. HR patients were divided according to tumour size and MI: the HR1, HR2 and HR3 groups. The five-year RFS rates of the NHR-PNI-H, NHR-PNI-L, HR1, HR2 and HR3 groups were 97.3%, 93.5%, 74.1%, 61.7% and 24.4%, respectively (p < .001). The area under the curve (AUC) for the NIH-PNI stratification, modified NIH criteria, NIH criteria (2002), AFIP criteria and nomogram were 0.857, 0.807, 0.817, 0.843 and 0.831, respectively.The proposed NIH-PNI stratification was able to distinguish among five groups in terms of risk of recurrence.A further modification to the NIH risk criteria for GISTs was proposed (‘NIH-PNI stratification’). Non-high risk (NHR) patients were divided into NHR-PNI-H and NHR-PNI-L groups. High risk (HR) patients were divided to HR1, HR2 and HR3 groups. The five-year RFS rates were 97.3%, 93.5%, 74.1%, 61.7% and 24.4%, respectively (p < .001). The AUC for the NIH-PNI stratification, modified NIH criteria, NIH criteria (2002), AFIP criteria and nomogram were 0.857, 0.807, 0.817, 0.843 and 0.831.