Role of radiotherapy in the management of organ transplant recipients diagnosed with non-melanoma skin cancers

Organ transplantation has had a major effect on the lives of thousands of patients worldwide. In Australia and New Zealand, over 13 000 patients have become organ transplant recipients (OTR). Following transplantation, patients require lifelong immunosuppression to prevent organ rejection. The loss of immune surveillance results in OTR experiencing a higher incidence of infection and malignancy in comparison with the general (immunocompetent) population. Non-melanoma skin cancer (NMSC) is the most common malignancy worldwide, arising most often on the sun-exposed head and neck. Organ transplant recipients experience a higher incidence of NMSC when compared with the general population and a higher incidence of squamous cell carcinoma compared with basal cell carcinoma. Organ transplant recipients also develop NMSC at a younger age and experience multiple new NMSC. Australians experience the highest incidence of NMSC in the world with a consequence that NMSC arising in OTR can lead to significant morbidity and even mortality. Radiation oncologists treating patients with skin cancer will almost certainly make recommendations in the setting of NMSC arising in OTR. The aim of this article is to discuss the role of radiotherapy in the management of OTR diagnosed with NMSC. The emphasis will be on the treatment of patients with a high-risk NMSC (e.g. squamous cell carcinoma, Merkel cell carcinoma, unfavourable basal cell carcinoma) because this reflects the most common clinical scenario in which a recommendation of radiotherapy, usually adjuvant, may be considered.