Chapter 30: Skin Cancer in the Organ Transplant Patient

INTRODUCTION

Advances in the management of solid organ transplantation recipients (OTR) have led to improved overall survival. However, patients face many consequences of being on long-term immunosuppression, including an increased risk of developing premalignant and malignant skin cancers. This is likely to pose an increasing challenge to dermatologists, as the number of patients receiving a solid organ transplant continues to grow and the life expectancy of these patients continues to increase. Skin cancers are the most common malignancy posttransplantation, comprising almost 40% of posttransplant malignancies, and tend to behave more aggressively than in nontransplant patients.¹ The increased risk of skin cancer impacts patient morbidity and quality of life post transplantation, and management of such cases places a significant burden on diminishing health care resources.

Epidemiology

Nonmelanoma skin cancers (NMSC) are the most frequent cutaneous malignancies in OTRs, with squamous cell carcinomas (SCC) and basal cell carcinomas (BCC) representing about 90% to 95% of the total in multiple reported cohorts.^2,3 Although the incidence of both types of malignancies is increased, the rate of SCC is disproportionately higher. In the immunocompetent population, BCC is the more common type of NMSC. However, in the transplant population the ratio is reversed with the ratio of SCC to BCC of at least 4:1.^4,5 Although the risk of BCC is increased 10 to 16 fold, SCC occurs at a frequency 65 times that of the general population.^1,6 OTRs are also at increased risk for developing other premalignant and malignant cutaneous conditions, including actinic keratoses (AKs), Bowen’s disease (SCC in situ), malignant melanoma (MM), Kaposi’s sarcoma, Merkel cell carcinoma (MCC), atypical fibroxanthoma (AFX), lymphoma, and angiosarcoma.^7–10 However, the incidence of SCC predominates in this population.

The majority of transplant patients usually develop multiple SCCs. The time period between transplantation and development of a skin cancer varies from a few months to up to 20 years, depending on the length of time after transplantation, the level of sun exposure, skin type, and other risk factors predisposing to SCC (Table 30-1).¹ About 25% of OTRs will develop a second SCC within 13 months and 50% within 3.5 years of their first SCC.¹¹ The increased incidence of SCC in OTRs is such that the diagnosis of a first SCC has been shown to be predictive of the development of additional NMSC within 5 years.¹²