More epidermal p53 patches adjacent to skin carcinomas in renal transplant recipients than in immunocompetent patients: the role of azathioprine.

Immunosuppressive medication in renal transplant recipients (RTR) strongly increases the risk of cancers on sun-exposed skin. This increased risk was considered an inevitable collateral effect of immunosuppression, because UV-induced carcinomas in mice were found to be highly antigenic. Here, we posed the question whether immunosuppression also increases the frequency of p53-mutant foci ('p53 patches'), putative microscopic precursors of squamous cell carcinomas.