For years, organ transplant patients have been told their risk of developing skin cancer increases following their transplant surgery. However, according to a study published in October in JAMA Dermatology, the rate of risk of squamous cell carcinoma has decreased since the mid-1980s.

A team of researchers from Oslo University Hospital in Norway studied 8,026 patients who had received a heart, lung, kidney or liver transplant between 1968 and 2012. The patients' data were linked to a national cancer registry, which allowed the team to look for trends associated with skin cancer.

The researchers found the risk of squamous cell carcinoma peaked in patients who had transplants between 1983 and 1987 and declined among patients who had transplants after 1993. For patients who had transplantation surgery after 1993, the risk of developing squamous cell carcinoma was half what it was from 1983 to 1987.

"Less aggressive and more individualized immunosuppressive treatment and close clinical follow-up may explain the decline," the authors wrote in the study. "Still, the risk of squamous cell carcinoma in organ transplant recipients remains much higher than in the general population and should be of continuous concern for dermatologists, transplant physicians and patients."

Indeed, the risk of other types of skin cancer following transplant surgery remains high. Specifically, kidney transplant recipients are at greater risk of developing melanoma.

A study published in JAMA Dermatology in July found that kidney transplant patients were 4.9 times more likely to develop melanoma than people in the general population. Specifically, of 105,174 kidney transplant recipients, 488 developed melanoma following transplant surgery. The median timeline to development of the cancer was 1.45 years following transplantation.

Most who developed melanoma were male, nearly all were white, and those who developed the skin cancer were 11 years older than kidney recipients who didn't. They were also more likely to be taking the common immunosuppressants cyclosporine or sirolimus than those without melanoma.

"Renal transplant recipients had greater risk of developing melanoma than the general population. We believe that the risk factors we identified can guide clinicians in providing adequate care for patients in this vulnerable group," the authors wrote in the study.

Another study from April found the cancer risk for children who have organ transplants is 19 times higher than members of the general population. While the study found that the risk is higher, it also found that most children who have transplants don't get cancer.

Less than 400 of some 18,000 transplant recipients developed some form of cancer four years after transplant. Researchers say the children who did development cancer did so for one of two reasons: immune-suppressing medications necessary following a transplant or the Epstein-Barr virus.

Overall, the study found that children's risk for Hodgkin's lymphoma was increased 19-fold. The risk of leukemia was four times higher among pediatric transplant recipients, and there was an elevated risk for developing multiple myeloma, and liver and kidney cancer as well among pediatric patients.

"The field of immunotherapy is still in its infancy," said Dr. Daniel Weschler, associate professor of pediatric hematology and oncology at Duke University. "We still need to learn more about the power of the treatments, but also their potential side effects."