Epidemiology and clinical evolution of non-melanoma skin cancer in renal transplant recipients: a single-center experience in São Paulo, Brazil.

BACKGROUND

Non-melanoma skin cancer (NMSC) is very common among renal transplant recipients (RTRs) as a result of the immunosuppressed status of these patients and other factors. Few studies have examined the clinical characteristics and evolution of NMSC in RTRs in tropical countries.

OBJECTIVES

The aim of this study was to characterize the epidemiology and clinical evolution of NMSC in RTRs.

METHODS

We conducted a retrospective study including 68 RTRs with NMSC diagnosed from July 2004 to December 2009 with a minimum follow-up of three years. We analyzed demographic and transplant- and NMSC-related data.

RESULTS

The mean age of patients at the first diagnosis of NMSC was 51 years (range: 29-71 years). Most first diagnoses occurred within nine years post-transplant. The majority of patients (n = 48) had Fitzpatrick skin phototype II, although NMSC was also observed in those with skin phototypes III and IV. Forty-six (67.6%) RTRs had received a kidney from a living donor. Fifty-five (80.9%) RTRs had received cytotoxic immunosuppressives, 51 (75.0%) had received calcineurin inhibitors, and two (2.9%) had received mTOR inhibitors. Most of the RTRs developed about eight NMSC lesions, but up to 25 NMSC lesions were diagnosed in one patient. Most lesions (67.6%) were located on sun-exposed areas. Squamous cell carcinoma (SCC) represented the predominant tumor type, accounting for 70.6% of all tumors, whereas basal cell carcinoma accounted for 29.4% of all tumors. Invasive SCC predominated over in situ SCC. Finally, 48.5% of patients had a previous history of viral warts.

CONCLUSIONS

Long-term use of immunosuppressive therapy increases the risk for tumor occurrence. Multiple NMSC tumors can develop in patients in tropical countries, even in patients with a high skin phototype. Therefore, RTRs should understand the high risk for the development of malignant tumors and should be properly informed about the prevention and treatment of NMSC.