Threefold risk of death from cancer after solid organ transplant, says new Ontario study

07/01/2016

A new study from the Institute of Clinical Evaluative Sciences (ICES) and St. Michael's Hospital has shown that people who undergo solid organ transplantation are three times more likely to die from cancer than the general population, warranting more targeted cancer care for this vulnerable group.

Published today in the journal JAMA Oncology, the study examined anonymized health records for 11,061 patients who underwent solid organ transplantation in Ontario between 1991 and 2010. Nearly one-fifth of the deaths in this group over the twenty-year period were cancer-related: a rate nearly three times that of the non-transplant population. When the researchers excluded patients with pre-transplant malignancies, the overall rate continued to be twice that of the general population. The comparative cancer mortality rate was higher for children who had undergone transplantation and lower for patients over 60 years; however for all ages, cancer mortality remained higher for this population.

“We’ve known that solid organ transplantation recipients have an increased incidence of malignancy after transplantation compared to the general population, but until now studies have not separated deaths caused by recurrent pre-transplantation malignancies from deaths caused by new malignancies. Additionally, the data have not provided sufficient detail about cancer sites,” says Dr. Nancy Baxter, the senior author on the study who is a senior scientist at ICES and a surgeon at St. Michael’s Hospital. “We expect this study will refine knowledge about the risk of death from cancer in this population, so that we can more effectively target screening, prevention and treatment strategies.”

Two-thirds of cancer-related deaths in the study population were linked to new malignancies that appeared after transplantation. Skin cancer showed the highest incremental risk of death, at thirty times higher in those who received a transplant compared to those who did not. This was followed by cancer of the liver and Non-Hodgkin’s Lymphoma. Once a malignancy was diagnosed, transplant recipients were less likely to survive than non-transplant cancer patients.

“There are many explanations for the increased cancer mortality seen in this population,” says Dr. Sergio Acuna, the study’s lead author and a PhD student in clinical epidemiology and healthcare research at the University of Toronto who is supervised by Dr. Baxter. “For example, immunosuppression enables cancers to take hold more aggressively. Further, once a malignancy is diagnosed, these patients may receive less aggressive cancer treatment because of additional illness burden and frailty, and the fear that transplant rejection may occur.”

The researchers note that cancer incidence is expected to grow in this population over the next 10 years as the age of transplant recipients rises and improvements in survival with a functioning transplant lengthens patients’ exposure to immunosuppression. Cancer was the second leading cause of death in this study of transplant recipients.

“Transplant patients currently receive cancer screening and prevention recommendations similar to those for the general population, but the increased risk faced by this population calls for a more targeted approach,” says Dr. Baxter. “We suggest that ongoing screening strategies be more closely targeted to a patient’s history and specific cancer risk. Further, since the risk of death from cancer is very high for this population, we also recommend that healthcare providers counsel these patients to take every possible precaution to reduce their risk, including limiting sun exposure, quitting smoking, reducing alcohol consumption, improving diet, and increasing physical activity.”

“Cancer Mortality among Recipients of Solid Organ Transplantation in Ontario” was published today in the journal JAMA Oncology.

Author block: Sergio A. Acuna, Kimberly A. Fernandes, Corinne Daly, Lisa K. Hicks, Rinku Sutradhar, S. Joseph Kim, Nancy N. Baxter.

The Institute for Clinical Evaluative Sciences (ICES) is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy. For the latest ICES news, follow us on Twitter: @ICESOntario

St. Michael’s Hospital provides compassionate care to all who enter its doors. The hospital also provides outstanding medical education to future healthcare professionals in more than 23 academic disciplines. Critical care and trauma, heart disease, neurosurgery, diabetes, cancer care, and care of the homeless are among the Hospital’s recognized areas of expertise. Through the Keenan Research Centre and the Li Ka Shing International Healthcare Education Center, which make up the Li Ka Shing Knowledge Institute, research and education at St. Michael’s Hospital are recognized and make an impact around the world. Founded in 1892, the hospital is fully affiliated with the University of Toronto.