Cancer mortality among solid organ transplantation recipients: A systematic review and meta-analysis

Objectives: To evaluate the cancer mortality risk among solid organ transplant recipients through a systematic review and meta-analysis.

Methods: Systematic searches were conducted in PubMed (starting from 1965), ISI Web of Science (starting from 1900), MEDLINE (starting from 1976), and Scopus (starting from 1968) from the inception of each database until July 15, 2024. Studies published in English reporting at least one type of cancer mortality risk among recipients of any type of solid organ transplantation were included. The main outcomes were the standardized mortality ratio (SMR) for cancer mortality in transplant recipients compared to the general population, and the hazard ratio (HR) for cancer mortality in transplant recipients versus cancer patients without prior transplantation.

Results: Solid organ transplant recipients had a 2.06-fold increased cancer mortality risk (SMR, 2.06 [95 % CI, 1.56-2.71]) than the general population. Risks were higher in kidney (SMR 1.92 [95 % CI: 1.30-2.84]), liver (SMR 3.07 [95 % CI: 1.80-5.24]), and lung/heart (SMR 4.87 [95 % CI: 3.33-7.12]) transplant recipients. Cancer patients with prior transplantation had a 1.47-fold increased cancer mortality risk (HR 1.47 [95 % CI: 1.29-1.68]) than those without. East Asia female transplant recipients exhibited higher mortality risks from breast, ovarian, cervix and uterus cancers than those from other regions (SMR 3.13 [95 % CI: 1.93-5.07] vs. 1.16 [95 % CI: 0.88-1.53], P < 0.01).

Conclusions: Solid organ transplant recipients face significantly higher cancer mortality risks than the general population, highlighting the need for targeted cancer screening and interventions, especially for female solid organ transplant recipients from East Asia.