The Prognostic Impact of Pre-transplant BMI on Survival Rate of Liver Transplant Recipients with Hepatocellular Carcinoma

Abstract

Introduction: Obesity prevalence has continually risen over the years. Previous studies have shown the poor impact of obesity on long-term outcomes in patients who undergo orthotopic liver transplantation (OLT). Few reports have been published showing the prognostic impact of obesity in patients with hepatocellular carcinoma (HCC) who underwent OLT. Methods: We used the retrospective database of all OLTs performed at Cleveland Clinic between January 2004 and December 2009. Only patients with HCC were included in this study. Using WHO classification for BMI, these patients were stratified into 5 categories as follow: underweight ( < 18.5 kg/m2), normal weight (18.5-24.9 kg/m2), overweight (25.0-29.9 kg/m2), obese (30.0-34.9 kg/m2), and morbidly obese (≥35.0 kg/m2). Multivariable analysis was used to assess the impact of obesity on the patient survival post LT. Results: A total of 168 patients with HCC who underwent OLT from 2004 until 2009 were included in the study. Mean BMI at the time of diagnosis of HCC was (29.8±4.7). Among all patients, obesity was identified in 40% (68) versus morbid obesity in 16% (27). HCC was beyond Milan criteria in 29% (31) of patients. The vascular invasion was identified in 23.8% (40) of patients. Median follow up post OLT was 5 years. The parameters that determine the mortality rate among patients who underwent OLT for HCC were pre-transplant BMI, HCC beyond Milan criteria, presence of vascular invasion & the number/size of lesions seen on imaging & explants. After performing a variable selection method; BMI, Milan criteria & vascular invasion were included in the final model. Multivariable analysis showed that BMI≥29.9 is associated with increased rate of death among HCC patients who underwent OLT; HR 1.09 (1.03, 1.2), P value 0.004 (Fig 1). In addition, subjects within Milan criteria had 67% lower hazard than those beyond the Milan criteria; HR 0.33 (0.17, 0.65) P-value (0.001). Lastly, subjects with vascular invasion had twice the risk of dying than those without vascular invasion; HR 2.2 (1.2, 4.1) P-value (0.01). The number of reported deaths within 5 years post OLT was 49 patients (29.2 %). Cumulative survival rates were 91.1%, 76.6% & 70.3% at 1, 3 & 5 years, respectively (Fig 2).Figure 1Figure 2Conclusion: There is a strong association between Pre- transplant BMI & survival rate among adults who had orthotopic liver transplantation for HCC. There is a 9% increase in mortality for every 1 kg/m2 increase in BMI ≥ 29.9.