Multiple squamous cell carcinomas in a psoriatic patient following high-dose photochemotherapy and cyclosporin treatment: Response to long-term acitretin maintenance

Cumulative toxicity is a well known limitation of antipsoriatic treatments. In particular, the induction of multiple squamous cell carcinomas following long-term PUVA treatment is well established. In the present report, a psoriatic patient is described who was treated for more than 14 years with photochemotherapy (PUVA) and who received excessive amounts of topical corticosteroids. The patient developed, in total, 34 squamous cell carcinomas. In all, three squamous cell carcinomas developed during long-term PUVA treatment, and 21 carcinomas appeared during 16 months of treatment with cyclosporin. Subsequently, a marked inhibition of the occurrence of new tumours occurred during prolonged treatment with acitretin, and no new tumours have appeared during the last 4 years of continuous treatment with this retinoid at a dose of 60 mg/day. Modulation of the expression of PUVA-induced squamous cell carcinomas by cyclosporin and acitretin are discussed. The present report lends support to the hypothesis that cyclosporin causes an increased occurrence of PUVA-induced carcinomas, whereas acitretin (60 mg/day) is of value in preventing the occurrence of new squamous cell carcinomas in patients who were treated with longterm PUVA.