Organ Transplant Recipients May Be More Likely to Develop Aggressive Melanoma
Organ transplant recipients are twice as likely to develop melanoma as people who do not undergo a transplant and three times more likely to die of the skin cancer, suggested new research by a multi-institutional team.
The findings, reported by Robbins et al in the Journal of Investigative Dermatology, indicated that the immunosuppressive medications that transplant recipients receive—especially the high doses administered at the time of transplant—may make them more susceptible to later-stage cancers that are more difficult to cure. The researchers found that transplant recipients were four times more likely to be diagnosed with regional-stage melanoma.
Unsure of Cause
“We knew that melanoma was more likely in transplant recipients, but we thought it might be a function of intensive screening, since they are very likely to develop less deadly forms of skin cancer and are checked regularly by dermatologists,” said Hilary A. Robbins, MSPH, a PhD student in the Department of Epidemiology at the Johns Hopkins Bloomberg School of Public Health, who conducted much of the research while working at the National Cancer Institute. “To the contrary, we were surprised to see that transplant recipients were particularly at risk for developing melanomas that weren’t found until they had already spread.”
The researchers were also surprised to see that the risk of aggressive melanomas was especially increased within the first 4 years after transplant. Previously, they thought that immunosuppressant medications might act cumulatively and that these cancers would be more likely after many years of taking the drugs.
Some types of cancer are more common among immunosuppressed people, such as those infected with HIV and transplant recipients. But Dr. Robbins says these are typically cancers that are linked to viruses, like cervical cancer, Kaposi’s sarcoma, and lymphoma.
Study Details
For their research, Dr. Robbins and the team studied 139,991 non-Hispanic white transplant recipients in the Transplant Cancer Match Study, which was led by Eric A. Engels, MD, MPH, Senior Investigator at the National Cancer Institute. The study linked the Scientific Registry of Transplant Recipients, which captures data on all transplants in the United States, with 15 population-based cancer registries and included information on almost half of the country’s transplant population between 1987 and 2010. The researchers found 519 melanomas in this group and analyzed risk factors for developing melanoma.
Using a different data set, the researchers compared outcomes among 182 patients with melanoma in the transplant group with more than 130,000 other people with melanoma. Over 15 years, 27% of the transplant recipients died of their melanoma, compared with 12% of the nonrecipients. The researchers found that patients with melanoma who had received a transplant were three times more likely to die of their melanoma, even for melanomas that were diagnosed at an early stage or were very small.
The researchers found that the late-stage cases of melanoma were associated with use of immunosuppressive medications given at the time of transplant. Meanwhile, early-stage melanomas were more likely to be found in recipients who were administered azathioprine, the maintenance drug given long term to some transplant recipients. This drug is known to multiply the effects of ultraviolet radiation, which could lead to the development of melanoma.
Dr. Robbins said her group’s findings suggest that transplant candidates should be screened very carefully for skin cancers before receiving their transplant. She said it is possible that some of the melanomas could have been present at the time of transplant, but that immunosuppressive drugs allowed them to spread unchecked. Closer monitoring after transplant could allow melanoma to be detected earlier, preventing patients from developing metastatic cancer, she concluded.
Researchers are working to develop transplant protocols that reduce or eliminate the need for lifelong immunosuppressive medications, as they make organ recipients more likely to develop other medical problems.
Dr. Robbins is the corresponding author of the Journal of Investigative Dermatology article.
The research was supported in part by the Intramural Research Program of the National Cancer Institute. Dr. Robbins' work is currently supported by the Cancer Epidemiology, Prevention, and Control Training Grant.
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®.
