Importance — Solid organ transplantation recipients (SOTR) are at greater risk of developing some cancers than the general population, however because they are also at increased risk of mortality from non-cancer causes, the impact of transplantation on cancer mortality is unclear.
Objective — To describe cancer mortality in solid organ transplantation recipients and to assess whether solid organ transplantation recipients are at increased risk of cancer mortality compared to the general population.
Design — Population-based cohort study of patients who underwent solid organ transplantation between 1991 and 2010 with 85 557 person-years of follow up.
Setting — Ontario, Canada.
Participants — 11 061 solid organ transplantation recipients: 6 516 kidney, 2 606 liver, 929 heart, and 705 lung transplantations.
Exposure — Solid organ transplantation was identified using the national transplant register and linked to the provincial cancer registry and administrative databases.
Main Outcomes and Measures — Cancer mortality for SOTR was compared to the general population using standardized mortality ratios (SMR). Mortality and cause of death were ascertained by record linkage between the Canadian Organ Transplant Register, the Ontario Cancer Registry, and the Office of the Registrar General of Ontario death database.
Results — Out of 3 068 deaths, 603 (19.7%) were cancer-related. Cancer mortality in solid organ transplantation recipients was significantly elevated compared to the Ontario population (SMR 2.84, 95% CI: 2.61–3.07). The risk remained elevated when patients with pre-transplant malignancies (n=1,124) were excluded (SMR 1.93; 95% CI: 1.75–2.13). The increased risk was observed irrespective of transplanted organ and sex. The SMR for cancer death after solid organ transplantation recipients was higher in children and lower in patients >60 years, but remained elevated compared to the general population at all ages.
Conclusion and Relevance — Cancer death rate in solid organ transplantation recipients was increased compared to that expected in the general population; malignancy was in fact the second leading cause of death in these patients. Advances in prevention, clinical surveillance, and cancer treatment modalities for solid organ transplantation recipients are needed to reduce the burden of cancer mortality in this population.