A research team from Johns Hopkins Bloomberg School of Public Health found transplant recipients are more likely to develop aggressive forms of melanoma. The study entitled “Melanoma Risk and Survival Among Organ Transplant Recipients” appeared in the Journal of Investigative Dermatology.
Recipients of organ transplants undergo immunosuppressive therapy to avoid rejection of their new organs. The high dose of immunosuppressant drugs intends to inhibit patients’ immune system towards the transplanted organ. As a side effect, these patients also have an increased risk of developing other cancers. “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, the first author of this study, in a press release.
Now, this research team reported an increased incidence and aggressive behavior of melanoma in patients under transplant-related immunosuppression. “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,” added Robbins.
The researchers studied 139,991 non-Hispanic white transplant recipients using linked U.S. transplant-cancer registry data between 1987 and 2010. They compared 182 melanoma patients in the transplant group with over 130,000 additional people diagnosed with melanoma. The researchers found that in patients diagnosed with melanoma, 27 percent of organ transplant recipients died, when compared to 12 percent in the group of non-recipients. Both the risk of invasive melanoma and localized tumors was higher among transplant recipients. Localized melanomas were associated with azathioprine, a maintenance drug given long term to some transplant recipients. This drug is known to potentiate the effects of ultraviolet radiation, which causes the development of melanoma. On the other hand, late stage tumors may result from the T-cell depleting induction therapies.
Based on their results, the authors proposed transplant candidates to be screened very carefully for skin cancers before receiving their transplant. In addition, transplant recipients should be closer monitored after transplants to allow an earlier detection of melanoma, this way preventing patients from developing deadly metastatic cancer. They further suggested that some of the melanomas may have been present in patients at the time of transplant, but that immunosuppressive drugs allowed them to spread unchecked.
Other researchers are also working on new alternative transplant protocols to bypass the use of immunosuppressive drugs, thus reducing the risk of developing other medical problems in organ recipients.