Prognostic value of 11-factor modified frailty index in postoperative adverse outcomes of elderly gastric cancer patients in China

BACKGROUND: Preoperative evaluation of frailty is limited to a few surgical procedures. However, the evaluation in Chinese elderly gastric cancer (GC) patients remains blank. AIM: To validate and estimate the prognostic value of the 11-index modified frailty index (mFI-11) for predicting postoperative anastomotic fistula, intensive care unit (ICU) admission, and long-term survival in elderly patients (over 65 years of age) undergoing radical GC. METHODS: This study was a retrospective cohort study which included patients who underwent elective gastrectomy with D2 Lymph node dissection between April 1, 2017 and April 1, 2019. The primary outcome was 1-year all-cause mortality. The secondary outcomes were admission to ICU, anastomotic fistula, and 6-mo mortality. Patients were divided into two groups according to the optimal grouping cutoff of 0.27 points from previous studies: High risk of frailty marked as mFI-11(High) and low risk of frailty marked as mFI-11(Low). Survival curves between the two groups were compared, and univariate and multivariate regression analyses were performed to explore the relationship between preoperative frailty and postoperative complications in elderly patients undergoing radical GC. The discrimination ability of the mFI-11, prognostic nutritional index, and tumor-node-metastasis pathological stage to identify adverse postoperative outcomes was assessed by calculating the area under the receiver operating characteristic (ROC) curve. RESULTS: A total of 1003 patients were included, of which 13.86% (139/1003) were defined as having mFI-11(High) and 86.14% (864/1003) as having mFI-11(Low). By comparing the incidence of postoperative complications in the two groups of patients, it was found that mFI-11(High) patients had higher rates of 1-year postoperative mortality, admission to ICU, anastomotic fistula, and 6-mo mortality than the mFI-11(Low) group (18.0% vs 8.9%, P = 0.001; 31.7% vs 14.7%, P < 0.001; 7.9% vs 2.8%, P < 0.001; and 12.2% vs 3.6%, P < 0.001). Multivariate analysis revealed mFI-11 as an independent predictive indicator for postoperative outcome [1-year postoperative mortality: Adjusted odds ratio (aOR) = 4.432, 95% confidence interval (95%CI): 2.599-6.343, P = 0.003; admission to ICU: aOR = 2.058, 95%CI: 1.188-3.563, P = 0.010; anastomotic fistula: aOR = 2.852, 95%CI: 1.357-5.994, P = 0.006; 6-mo mortality: aOR = 2.438, 95%CI: 1.075-5.484, P = 0.033]. mFI-11 showed better prognostic efficacy in predicting 1-year postoperative mortality [area under the ROC curve (AUROC): 0.731], admission to ICU (AUROC: 0.776), anastomotic fistula (AUROC: 0.877), and 6-mo mortality (AUROC: 0.759). CONCLUSION: Frailty as measured by mFI-11 could provide prognostic information for 1-year postoperative mortality, admission to ICU, anastomotic fistula, and 6-mo mortality in patients over 65 years old undergoing radical GC.