John Libbey Eurotext

European Journal of Dermatology

Non-melanoma skin cancers in African American solid organ transplant recipients: regional bias or a real need for surveillance? Volume 27, numéro 5, September-October 2017

Tableaux

The rate of solid organ transplantation in non-white patients continues to increase. Our understanding of the epidemiology and risk of non-melanoma skin cancer (NMSC) in this population remains limited. Currently available data on NMSC in solid organ-transplant recipients (SOTRs) is predominantly derived from Caucasian patients. NMSC remains the most common neoplasm in the post-transplant setting. The incidence of squamous cell carcinoma (SCC), basal cell carcinoma (BCC), and melanoma is increased 65-fold, 10-fold, and 3-fold, respectively, in comparison with ethnically-matched control populations [1].Previously published studies in patients with ethnic skin, however, have been limited and report variable data [2-5]. A recent retrospective study on NMSC among 259 non-white SOTRs reported a total of 19 NMSCs in 15 patients (5.8%); this is in contrast with an overall low risk described in previous reports [6].

We conducted a retrospective analysis of self-identified non-Caucasian SOTRs referred to the Department of Dermatology at Johns Hopkins Hospital (JHH) between 1990 and 2007 with a minimum follow-up time of five years. Patients’ data and characteristics are shown in table 1. A total of 4,090 solid organ transplants were performed at JHH during this time frame, of which 1,114 patients self-identified as non-Caucasian. Among 1,114 patients, 180 (16%) were evaluated in the Department of Dermatology and were included in the study.

African Americans (AAs) represented the largest group of patients (n = 160; 89%). A total of six NMSCs were observed in four (2.5%) of the AA cohort. These included two squamous cell carcinomas in situ (SCCIS), one SCCIS with focus of invasion, one invasive SCC, and two BCCs. Three (3.9%) AA males (n = 77) and one (1.2%) female (n = 83) developed NMSC. These patients had received renal (n = 2), heart (n = 1), and lung (n = 1) transplants. Two SCC developed in non-sun-exposed areas (inguinal region, labja majora).

The main limitation of our retrospective analysis is the small sample size. However, the predominance of SCC remains consistent with previous reports, which show SCC as the most common NMSC among AAs, affecting 3 per 100,000 patients [7]. Furthermore, we only analysed a small proportion of patients (16%), who were examined in our dermatology clinic and had a histological diagnosis. Our study design represents the true referral bias based on chief complaint and perceived risk in this population. Appropriate dermatological evaluation of the entire cohort of patients with ethnic skin (1,114) may have had a significant impact on our observed incidence and the types of cutaneous neoplasms encountered. Potential risk factors for NMSC, such as sun exposure, family history, and smoking, were not analysed, given the variable availability of data in the retrospective analysis. Lastly, the reported ethnicity was derived from the patients’ history (self-report), which by itself introduces a bias.

Despite these limitations, our results support a higher risk of NMSC development in AA SOTRs than previously suspected in AAs. The observation of SCC in non-sun-exposed skin combined with patients’ perception of their skin colour and lowered inherent risk of skin cancer development, with biased referral patterns, may all contribute to a delay in, or missed, diagnosis. Continuing to elucidate risk factors for NMSC development in the growing population of non-Caucasian transplant recipients is imperative as it will allow us to develop more directed screening resources, counselling, and educational tools.

Disclosure

Financial support: none. Conflict of interest: none.