Abstract
BACKGROUND: Frailty is increasingly becoming a powerful prognostic factor for cancer patients. The purpose of this study was to investigate the prognostic effect of 5-modified frailty index (mFI-5) on adverse outcomes after surgery in older patients with esophageal cancer over 65 years of age. METHODS: Patients over 65 years old who underwent esophagectomy between January 1, 2014 and January 31, 2017 were included in the study analysis. The mFI-5 variables include hypertension, type Ⅱ diabetes, congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD), and independent functional status. Patients were divided into 3 groups: robust group (mFI-5, 0), prefrail group (mFI-5, 1) and frail group (mFI-5, 2 ~ 5). Primary outcome was 30-day mortality. Secondary outcomes were postoperative delirium and pneumonia. Logistic regression analyzes and COX analyzes were used to identify independent risk factors for outcomes. The receiver operating characteristic (ROC) curve analysis and decision curve analysis (DCA) were used to evaluate the predictive efficacy and clinical net benefit of different variables in predicting outcomes. Delong test was used to compare and discern the effectiveness of two ROC curves in a classification setting. RESULTS: A total of 699 patients were included in this retrospective cohort study, of which 342 (48.93%) in the robust group, 184 (26.32%) patients in the prefrail group, and 173 (24.75%) patients were in the frail group. Frail patients identified by mFI-5 had the highest incidence of postoperative 30-day mortality (frailty: 5.8% vs. prefrail: 1.6% vs. robust: 1.2%), delirium (22.5% vs. 14.7% vs. 2.9%, P < 0.001) and pneumonia (13.3% vs. 9.8% vs. 3.8%, P < 0.05). Multivariate stepwise regression analysis found that frailty was associated with a significantly increased risk of postoperative 30-day mortality [adjusted Odds Ratio (aOR) = 14.30, 95%CI: 4.87-42.03, P < 0.001], delirium (aOR = 6.82, 95%CI: 3.12-14.89, P < 0.001), and pneumonia (aOR = 4.12, 95%CI: 2.52-6.72, P < 0.001). mFI-5 combined with Age and ASA classification had the highest predictive value in predicting postoperative adverse outcomes in older patients with esophageal cancer [30-day mortality area under curve (AUC): 0.84; delirium AUC: 0.78, and pneumonia AUC: 0.67]. CONCLUSIONS: The 5-modified frailty index is a convenient and effective tool to predict postoperative 30-day mortality, delirium and pneumonia in older patients over 65 years old undergoing esophagectomy. The mFI-5 could guide clinical decision-making and become a highly promising prognostic scale for risk stratification of esophageal cancer older patients.