Solid Organ Transplant Recipients With Preexisting Malignancies in Remission May Be More Likely to Die, Develop New Cancers
Patients who had cancer before receiving an organ transplant were more likely to die of any cause, die of cancer, or develop a new cancer than organ recipients who did not previously have cancer, a new study published by Acuna et al in the journal Transplantation has found. However, the increased risk is less than that reported in some previous studies.
Previous research has shown that cancer survivors were at increased risk of cancer recurrence after a transplant. However, the findings regarding the risk of death and developing a new cancer were inconsistent.
Study Findings
This study was a meta-analysis of 33 cohort studies involving almost 400,000 patients in 12 countries. Organ recipients with previous cancer had at any given time a 1.5 times greater risk of dying than those with no previous cancer. They had a three times higher risk of dying from cancer and an almost two times higher risk of developing a new cancer. The association between higher rates of death, death from cancer, and new cancers did not vary according to the type of organ that was transplanted.
Lead author Sergio Acuna, MD, a physician and doctoral student in clinical epidemiology at St. Michael's Hospital in Toronto, said the study did not examine whether the association between higher death rates, higher rates of death from cancer, and the risk of developing new cancers was caused by characteristics of the organ donor or some other factor such as the type of immunosuppressant drug. It also did not look at patients who received a transplant for the treatment of their cancer, such as patients with liver cancer who may receive a liver transplant.
Reasons and Implications
The critical shortage of organs for transplants means that clinicians and policymakers must ensure scarce donor organs are given to the patients who would benefit the most from them. And as the population ages, the average age of transplant patients is also rising, meaning the number of organ recipients with previous cancers is expected to increase. Although the proportion of patients with previous cancers ranges from 0.4% to 5.4% in studies of all patients undergoing transplants in a given country, state, province or region, those patients accounted for as many as 7.4% of organ recipients in Ontario in 2010.
Dr. Acuna noted that previous studies have shown that transplant recipients with previous cancers were more likely to have received organs from “expanded-criteria donors” (older donors who may have had medical conditions such as high blood pressure or who died as a result of a stoke) or to have spent prolonged time on dialysis. Both of these are factors associated with deaths from cardiovascular incidents, such as a heart attack or stroke, and rejection of a transplanted organ.
Dr. Acuna said more research was needed to determine the length of time between when a patient was deemed to be in remission or cured of cancer before he or she could receive an organ transplant to minimize the risk of cancer recurrence without increasing the risk of death from other causes.
Nancy Baxter, MD, PhD, senior author of the study and a colorectal surgeon at St. Michael's, said transplant patients with a history of cancer might also need closer monitoring to detect recurrent and new cancers early. No specific recommendations on screening for second malignancies in these patients exist. She said there was also a need to better understand and mitigate the cancer risk in transplant recipients with a history of cancer, focusing on cancer prevention and early detection.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
