Rochester, MN - Heart-transplant recipients have a high risk for skin cancer due to the immunosuppressant drugs they take to prevent rejection of the donor organ, a retrospective study at the Mayo Clinic found.

Dr Jerry Brewer and colleagues collected data on skin cancer for all 312 patients who received a heart transplant at the Mayo Clinic from 1988 to 2006. Results of the study, appearing in the December 2009 Archives of Dermatology, show that the patients had a total of 1395 new skin cancers over a total of 2097 patient-years, for an average rate of 0.43 cancers per patient-year. Cancers per patient ranged from 0 to 306 squamous-cell carcinomas and from 0 to 17 basal-cell carcinomas.

The cumulative incidence rates for any skin cancer were 20.4%, 37.5%, and 46.4% at five, 10, and 15 years after heart transplant, respectively. The cumulative incidence of squamous-cell carcinoma after the first basal-cell carcinoma was 98.1% within seven years.

The multivariate analysis showed a significantly increased risk of basal-cell carcinomas in patients on mycophenolate mofetil (CellCept, Roche). Tacrolimus and sirolimus were nonsignificantly correlated with a decreased risk of basal-cell and squamous-cell carcinomas, respectively. However, Brewer et al point out that these correlations may not hold in future studies "because of the complexities of modeling medication doses over time." Additional risk factors for squamous-cell carcinomas include posttransplant nonskin cancer, increased age, and other heart-failure etiologic factors, according to the study. Also, posttransplant herpes simplex viral infection further increased the risk of basal-cell carcinoma.

Brewer told that although the link between immunosuppressive therapy in heart-transplant patients and skin cancer is well established, there have not been many studies delineating the incidence, tumor burden, and risk factors for different types of skin cancers in heart-transplant recipients.

Although the tumor burden for these patients can be "incredible," Brewer said, the Mayo Clinic has been able to significantly reduce their patients' risk of dying from skin cancer with a multidisciplinary approach to cancer prevention involving members of the transplant team, oncologists, and dermatologists. This approach includes appropriate patient education on skin-cancer prevention and regular follow-up by a dermatologist.

"The take-home lesson is that skin cancer in cardiac-transplant patients is not trivial and has the potential to significantly affect their quality of life and potentially even cause death," Brewer said. "The time of transplantation is one of the best times to educate patients. Patients should be educated by their transplant physician that having a cardiac transplant means, from that point on, religious use of sunscreens daily (even during the winter), avoiding [going outside during] the peak hours of the day, performing self skin examinations monthly, and being seen by a dermatologist at least annually."