As more Canadians survive organ transplants, they show a higher risk of dying from cancer than average, a new study suggests.
People who receive liver, lung and other solid organs have a higher incidence of cancers, but it wasn't clear whether they're also more likely to die from the disease, since many cancers are treatable.
To find out, Dr. Nancy Baxter, a colorectal surgeon at St. Michael's Hospital in Toronto followed 11,000 patients who had organ transplants in Ontario over a 20-year period, using data from the Canadian organ registry and the province's cancer registry.
Of 3,068 deaths among the recipients, 603 or 20 per cent were cancer related, Baxter said in Thursday's issue of the journal JAMA Oncology. Overall, cancer mortality was almost three times higher among transplant patients compared with the general population.
"I think that we've done a really great job in getting people to live longer and live well with their transplants," Baxter said. "It's time to shift the focus."
Skin cancer topped the list of malignancies causing death among those in the study.
Baxter wants transplant patients to be aware of their higher risk of cancer and for health-care providers to focus on prevention and screening.
Aside from general advice such as limit sun exposure, quit smoking, improve diet, increase physical activity and get the HPV vaccine, Baxter and her co-authors said transplant recipients likely need a tailored approach to cancer screening.
For example, lung cancer screening with CT may miss some lung transplant recipients and even organized screening programs have gaps.
Cancer was the second-leading cause of death among transplant recipients after heart-related causes.
Immune systems suppressed
Scientists have proposed several possible explanations for why transplant recipients have worse outcomes than patients with cancer who haven't had a transplant. People who receive an organ donation are immunosuppressed, and their cancers may be treated less aggressively.
The authors of a journal commentary published with the researcher's robust methodology and how the distinguished deaths from a cancer recurrence from a new cancer.
But the "provocative report" doesn't establish what needs to be done for transplant recipients at increased risk of death and the explanations for increased risk of death are hypotheses that haven't been tested, said Dr. Marianne Schmid of the University Medical Center in Hamburg, Germany.
The study was funded by the Canadian Institutes of Health Research and the Institute for clinical Evaluative Sciences.