Study Raises Questions on Benefits of Organ Transplant

Solid-organ transplants increase the risk of death due to cancer—irrespective of gender or the type of transplant—compared with the general population, a study published in JAMA Oncology has found. Cancer was the second leading cause of death in solid-organ transplant recipients (SOTRs).

For senior author Nancy N. Baxter, MD, PhD, chief of general surgery at St. Michael’s Hospital in Toronto and faculty at the University of Toronto, this was not an expected finding. “We haven't known the impact that cancer has on them, because they have a lot of other things going on as well that can affect their health,” Baxter explained. “We found there was an increased risk of death from almost every cancer. That was in all age groups, but more for younger individuals than older individuals. It seems that cancer is a real burden for transplant patients.”

The study analyzed data on 11,061 SOTRs who had received a solid-organ transplant between 1991 and 2010, who were followed-up through December 2011. The cohort included individuals who had received kidney, liver, heart, and lung transplantations. A little over 35% of the recipients were women and the median age of the cohort was 49 years. Of the 3068 deaths that were recorded, 603 (20%) were related to the recipient suffering from cancer. Even after they eliminated patients with premalignant neoplasm from their analysis, the risk of cancer mortality in SOTRs remained high, the authors write, irrespective of the transplanted organ.

SOTRs were nearly 30 times more likely to die from non-melanoma skin cancers, 13 times more likely to die from liver cancer, and nearly 10 times more likely to die from non-Hodgkin lymphoma. The risk of dying from bone or soft tissue cancer was about 5 times higher, the research revealed. Children were nearly 85 times more likely to die of cancer following a solid-organ transplant, while older recipients (more than 60 years) had a lower probability of dying, albeit higher than a non-transplant individual in the same age group.

It all boils down to the manipulation of our immune system, the authors believe. Transplant recipients are administered immunosuppressants to trick their body into accepting the foreign organ and avoid rejection. This can leave the body vulnerable to cancer-causing viruses, such as the human papillomavirus that causes cervical cancer, the Epstein-Barr virus that can cause lymphoma, and hepatitis B and C viruses known to play a role in the development of liver cancer, Baxter explained.

One way to combat this problem is to include cancer screening during regular follow-up in SOTRs. This could help detect problems, if any, early following the transplant procedure and help stop the cancer early. Baxter also suggests lifestyle changes, such as smoking cessation, because lung cancer was a leading cause of death in their research cohort.