S. Chong1,2, P. Stevenson1, A. Althabteh3, N. Isbel1, S. Campbell1, A. Grifﬁn1, A. Green4, K. Khosrotehrani1,2
Background: Organ transplant recipients (OTR) have a higher incidence of keratinocyte cancers especially squa- mous cell carcinoma and often a more aggressive course with poorer outcomes due to immunosuppression. A Queensland study showed the prevalence of keratinocyte cancers and actinic keratosis in OTR was 27% and 89% respectively.1 Oral sirolimus is an immunosuppressant that has been proven to reduce skin cancer, however comes with signiﬁcant toxicity.2 Although topical sirolimus has been used widely in dermatology, especially in genoder- matoses, it has not been tested for skin cancer prevention.
Aim: We evaluated the safety and efﬁcacy of 1% topical sirolimus in reducing keratinocyte lesions and skin cancer in OTR.
Methods: 30 OTR patients were randomized to receive intervention on the dorsum of one hand and wrist, and placebo on the opposite hand and wrist. The topical prepa- rations were applied nightly for 12 weeks. Primary out- come measure was the change in surface and number of keratotic lesions compared to initiation day. Secondary outcome measure was the development of skin cancers. We also noted tolerability and potential adverse events.
Results: The topical preparation was well tolerated. Sys- temic levels of sirolimus were below 1 ng/ml, well below the toxicity levels reached through oral delivery (5–15 ng/ ml). There was an overall reduction of 23.8% in keratotic lesions at the end of the 12 weeks. 3 patients developed SCCs in their dorsum hands and forearms 3 to 5 months post initiation day.
Conclusion: The preliminary results of our pilot study are promising and warrant further larger scale study.
1. Iannacone MR, Sinnya S, Pandeya N, Isbel N, Campbell S, Faw- cett J, et al. Prevalence of Skin Cancer and Related Skin Tumors in High-Risk Kidney and Liver Transplant Recipients in Queens- land, Australia. JID. 2016;136(7):1382–6.
2. Campbell SB, Walker R, See Tai S, et al. Randomized Controlled Trial of Sirolimus for Renal Transplant Recipients at High Risk for Nonmelanoma Skin Cancer. American Journal of Transplan- tation. 2012;12(5):1146–1156.