Lung cancer incidences after liver transplantation: A systematic review and meta-analysis

Liver transplantation has made significant progress in recent decades. Lung cancer is one of the most frequently occurring cancers after liver transplantation. However, the risk of lung cancer among liver transplant patients compared with the general population is unclear. The aim of this meta-analysis was to assess the risk of developing lung cancer after liver transplantation.

All eligible studies published in PubMed, Web of Science, and Embase from database inception to April 2022 were included. Standardized incidence ratio was used to describe the increased risk of lung cancer in liver transplant recipients as compared with the general population. The random-effects model was used for the calculations. A funnel plot and Egger test were performed to assess the potential publication bias.

Our meta-analysis included 15 studies, which involved 76,897 liver transplantation patients. Studies included in this review showed significant heterogeneity (I²  = 65.3%; p < 0.001), which required a random-effects model for effect pooling. The results indicated a significant higher risk of developing lung cancer in liver transplant patients than the general population with a pooled SIR of 2.06 (95% CI: 1.73, 2.46, p < 0.001). When stratified by region, no significant regional difference was observed. It showed a similarly doubled risk of lung cancer in Europe and North America, but an insignificantly increased risk in Asian populations. The sensitivity analysis by removal and substitution of each literature did not change the results.

Our meta-analysis suggests that liver transplant patients are twice as likely as the general population to develop lung cancer. Further research on risk factors for the development of lung cancer after liver transplantation should be conducted and appropriate surveillance protocols should be developed to reduce the risk of its occurrence.