Solid-organ transplant recipients have a higher rate of cancer mortality than that expected in the general population, according to a Canadian study published in JAMA Oncology. Cancer mortality among transplant recipients “was significantly elevated compared with the Ontario population,” with a standardized mortality ratio of 2.84 (95% confidence interval [CI], 2.61–3.07). “The increased risk was observed irrespective of transplanted organ,” the investigators found.
The population-based cohort study identified 11,061 patients who underwent solid-organ transplantation in Ontario, Canada, between 1991 and 2010. This included 6,516 kidney, 2,606 liver, 929 heart, and 705 lung transplantations. The 85,557 person-years of follow-up continued through December 31, 2011.
The median age of the transplant recipients was 49 (range, 37–58) years, and 4,004 (36.2%) were women. “Of 3,068 deaths, 603 (20%) were cancer related,” Sergio A. Acuna, MD, of the University of Toronto, and colleagues reported. “Although the risk of noncancer death exceeded cancer-related mortality (P < .001), the risk of cancer-related death increased steadily over time,” the researchers noted. Cancer was the second-leading cause of death overall for transplant recipients (20%) after cardiovascular disease (24%).
“Lung cancers were the most common cause of cancer death (n = 126 [21%]), followed by liver cancers (n = 107 [18%], most due to cancers that predated transplantation), non-Hodgkin lymphoma (n = 96 [16%]), and colorectal cancer (n = 43 [7%]),” the researchers reported.
The risk of cancer mortality “remained elevated when patients with pretransplant malignant neoplasms (n = 1,124) were excluded (standardized mortality ratio, 1.93 [95% CI, 1.75–2.13]),” the researchers wrote. Malignant neoplasm was the reason for transplantation in 442 patients (39%) of those with a history of pretransplant neoplasms; 234 patients (21%) had malignant neoplasms diagnosed around the time of transplantation; and 448 patients (40%) had malignant neoplasms in presumed remission.
The mortality ratio was higher for children receiving solid-organ transplantation (standardized mortality ratio, 84.61 [95% CI, 52.00–128.40]) and lower in patients older than 60 years (standardized mortality ratio, 1.88 [95% CI, 1.62–2.18]) “but remained elevated compared with the general population at all ages,” the researchers found.
“A tailored approach to cancer screening is likely required for transplant recipients,” the investigators suggested. “Given the high mortality of lung cancers, strategies to improve pretransplant and posttransplant lung cancer screening may be necessary. Screening with low-dose computed tomography in high-risk groups such as thoracic organ recipients and patients with smoking history could be considered. Specific cancer screening strategies for liver cancers should be evaluated in hepatic transplant recipients and for melanoma, colorectal, oral cavity, and prostate cancer in kidney recipients. Finally, cancer preventive strategies such as limitation of sunlight exposure, sun protection, smoking cessation, reduction in alcohol consumption, dietary changes, and physical activity should also be considered.”
Acuna SA, et al: JAMA Oncol. January 7, 2016 (early release online).
