# Risk Factors of All-Causes Mortality and De Novo Solid Malignancy Following Liver Transplantation: A Single-Center Survival Analysis in Iran

## TL;DR

This study identifies age and immunosuppressive drugs as risk factors for mortality and new cancers in liver transplant patients in Iran.

## Contribution

The study identifies specific immunosuppressive drugs and age as independent risk factors for mortality and de novo malignancy after liver transplantation.

## Key findings

- Age and sirolimus use were significantly associated with improved survival after liver transplantation.
- Age and azathioprine use were linked to an increased risk of de novo solid malignancy.
- The 20-year survival rate was 58%, and the 20-year malignancy-free rate was 78%.

## Abstract

De novo solid tumors are considered major causes of mortality in liver transplant recipients. This retrospective cohort study aimed to assess the risk factors of all-causes mortality and de novo solid malignancy, as co-primary outcomes, following liver transplantation.

The medical records of 2,600 patients who underwent liver transplantation at Abu-Ali Sina Charity Hospital in Shiraz, Iran, between 2010 and 2023, were evaluated to collect data of eligible patients. Cox proportional hazards regression was used to determine factors affecting mortality and de novo malignancy.

A total of 419 patients were included. Among them, 127 individuals (30.3%) died and 53 patients (12.6%) received a de novo solid malignancy diagnosis during the study period. The 1-, 5-, 10-, 15-, and 20-year survival rates of patients were 85%, 76%, 69%, 61%, and 58%, respectively, and the 1-, 5-, 10-, 15-, and 20-year proportion of patients free from de novo malignancy were 97%, 90%, 83%, 78%, and 78%. Age (hazard ratio [HR]=1.03, 95% confidence interval [CI]: 1.02 to 1.05, P value<0.001) and sirolimus (HR=0.44, 95% CI: 0.31-0.63, P value<0.001) were significantly associated with survival, and age (HR=1.05, 95% CI: 1.02-1.07, P value<0.001) and azathioprine (HR=5.85, 95% CI: 2.47-13.87, P value<0.001) were linked to an increased risk of de novo solid malignancy.

Recipient’s age and immunosuppressive regimen are independently associated with mortality and malignancy development following liver transplantation. However, this study is limited by its retrospective design and single-center setting.