The Augural Interplay of Myosteatosis and Gamma-Glutamyltransferase in Patients Undergoing Comprehensive Surgical Intervention for Cholangiocarcinoma
Authors: Liu Yan , Sun Xueguo , Zhang Jingli , Li Xiaoyun , Song Guanghui , Lu Yanyan , Li Qian , Zhang Lingyun , Jing Xue 
Published: August 2023

Abstract
Background: Myosteatosis, an established inauspicious prognostic factor prevalent among patients battling gastric cancer, pancreatic cancer, and other malignant neoplasms, has demonstrated associations with unfavourable outcomes in cholangiocarcinoma (CCA) cases. Concurrently, studies have proposed that preoperative elevation in γ-glutamyltransferase (GGT) levels might serve as autonomous harbingers of dismal outcomes in intrahepatic cholangiocarcinoma (ICC) sufferers. Yet, the conjoined prognostic potency of GGT and myosteatosis in patients diagnosed with CCA undergoing comprehensive surgical excision remains shrouded in uncertainty.
Methods: This retrospective examination encompassed 156 CCA patients undergoing comprehensive surgical resection at the Affiliated Hospital of Qingdao University between January 2017 and March 2022. Serum gamma-glutamyltransferase (GGT) data, among other pertinent clinical intel, were harvested within a month preceding the surgical intervention. Body composition assessment was executed utilising computed tomography (CT) scans at the third lumbar vertebrae level, aided by the application of the Slice-O-Matic software. Group classification of myosteatosis and GGT was conducted based on reference and cut-off values, computed through receiver operating characteristic (ROC) curves. The Kaplan-Meier method was employed for survival analysis, while the log-rank test was used for evaluating differences in recurrence and survival. Cox regression models were ultimately utilised to discern risk factors impacting overall survival (OS) and recurrence-free survival (RFS) in CCA patients.
Result: The myosteatosis group, with a mean age of 64.3 ± 8.0 years, included 83 patients, whereas the non-myosteatosis group, with a mean age of 58.3 ± 9.8 years, comprised 73 patients. Employing the receiver operating characteristic (ROC) curve and Youden's index, the optimal cut-off value for gamma-glutamyltransferase (GGT) was calculated to be 136.5. Both overall survival (OS) and recurrence-free survival (RFS) were significantly curtailed in the myosteatosis group relative to the non-myosteatosis group (P = 0.017 and P = 0.013, respectively). Furthermore, the OS and RFS were reduced in the GGT ≥ 136.5 group compared to the GGT < 136.5 group (P = 0.007 and P = 0.006, respectively). Yet, these factors did not surface as independent predictors of adverse prognosis in cholangiocarcinoma (CCA) patients. Notably, those patients exhibiting both myosteatosis and GGT ≥ 136.5 experienced the direst OS and RFS outcomes (P = 0.008 and P = 0.006, respectively).
Conclusion: Myosteatosis, combined with gamma-glutamyltransferase (GGT) levels ≥ 136.5, portend a truncated overall survival (OS) and recurrence-free survival (RFS) in patients with cholangiocarcinoma (CCA) undergoing comprehensive surgical resection. Patients exhibiting both myosteatosis and preoperative GGT levels ≥ 136.5 bore the gravest prognosis, thereby necessitating heightened vigilance in clinical praxis.