Clinical significance of the preoperative cachexia index as a prognostic predictor in patients with extrahepatic cholangiocarcinoma undergoing radical surgery.

Abstract

e16336 Background: The cachexia index (CXI) has been proven to have prognostic value in various tumors. Extrahepatic cholangiocarcinoma (ECC) is an aggressive malignancy with poor postoperative outcomes. Aim of this study was to evaluate the prognostic significance of CXI in ECC patients undergoing radical surgical resection. Methods: A total of 244 patients diagnosed with ECC who underwent radical surgical resection from January 2016 to December 2021 were retrospectively involved. CXI was calculated using the formula: CXI = (skeletal muscle index × serum albumin level) / neutrophil-to-lymphocyte ratio (NLR). Clinicopathological characteristics and survival outcomes were compared between the low-CXI and high-CXI groups. Results: A total of 244 ECC patients were divided into low-CXI group (n = 122) and high-CXI group (n = 122) according to the median value. Patients in the low-CXI group had a lower skeletal muscle area(SMA), hemoglobin, lymphocyte, serum sodium, serum calcium, serum phosphorus, and a higher total bilirubin, conjugated bilirubin, alkaline phosphatase. The median overall survival(OS) and disease-free survival(DFS) times of the low-CXI group were significantly worse than those of the high-CXI group(OS, 38 vs 53 months, p = 0.0288; DFS, 34 vs 53 months, p = 0.0398). Multivariate Cox regression analysis revealed that age(HR = 1.032, 95%CI = 1.007-1.057, p = 0.010), a preoperative CXI(HR = 0.996, 95%CI = 0.991-1.000, p = 0.047), TNM stage(p < 0.001), and perineural invasion(HR = 0.483, 95%CI = 0.290-0.805, p = 0.005) were prognostic factors for ECC patients undergoing radical surgery. No significant prognostic correlation was observed between CXI levels and outcomes in the high CA19-9 group(p = 0.1431) and hilar cholangiocarcinoma group(p = 0.1649). Conversely, in the CA199-normal group(p = 0.0324), jaundiced group(p = 0.0353), non-jaundiced group(p = 0.0138), and distal cholangiocarcinoma group(p = 0.0324), the low-CXI group consistently demonstrated poorer prognosis. Conclusions: Preoperative CXI can serve as a useful prognostic biomarker for postoperative outcomes in ECC patients.