Sirolimus Lowers NMSC Risk in Transplant Recipients
Switching from a calcineurin inhibitor (CNI) to sirolimus for immunosuppression may decrease the risk of nonmelanoma skin cancer (NMSC) in kidney transplant recipients with a history of NMSC, according to researchers.
In a prospective, multi-center study, Scott B. Campbell, MD, Consultant Renal Physician at Princess Alexandra Hospital, and collaborators randomly assigned 86 kidney transplant recipients (at least one year post-transplant) with a history of NMSC to continue receiving CNI therapy or convert to sirolimus. The authors noted that sirolimus is known to have antineoplastic effects.
The mean length of follow-up for the intent-to-treat population (that is, on- and off-therapy periods) was 1.68 and 1.74 years for the sirolimus and CNI groups, respectively. The annual NMSC rate was significantly lower with sirolimus than with CNI (1.31 vs. 2.48 lesions/patient-year). Squamous cell carcinoma also occurred at a lower rate in the sirolimus group. The rate of basal cell carcinoma was similar for both groups. A significantly lower proportion of sirolimus recipients experienced new or recurrent NMSC (56.4% vs. 80.9%), Dr. Campbell's group reported in the American Journal of Transplantation.
Acute rejection occurred in none of the sirolimus patients and in one of the CNI patients. The two groups had a similar incidence of treatment-emergent adverse events, but discontinuation rates were significantly higher in the sirolimus group (46.2% vs. 0%).
The authors noted that kidney transplant recipients have greater rates of de novo and recurrent neoplasms compared with the age-matched general population. Most of these cancers involve the skin. NMSC accounts for more than 90% of post-transplant skin cancers, the investigators noted. They cited previous research showing that among kidney transplant recipients, about 75% of those who had at least one skin cancer prior to transplantation will develop an average of 16-20 NMSC lesions post-transplant, with a median of six months to onset.
“The results of this and other studies examining the reduction of skin and nonskin malignancies suggest a benefit in converting to a sirolimus-based immunosuppressive regimen,” the researchers concluded.