Melanoma and non-melanoma skin cancer in psoriatic patients treated with high-dose phototherapy

Objectives: The carcinogenic effect of plus ultraviolet A (PUVA)-therapy in psoriatic patients has been widely demonstrated, while data on the safety of narrow band (311nm) ultraviolet B (nb-UVB) are scarce. We investigated the occurrence of melanoma and non-melanoma skin cancer (NMSC) in psoriatic patients treated with nb-UVB or PUVA-therapy. Methods: This retrospective study included patients affected by psoriasis, who had been treated with nb-UVB or PUVA-therapy. Clinical data and phenotypic risk factors were collected and a total body examination was performed at a routine appointment during the study period. Results: We examined 92 patients (60 males and 32 females; mean age: 53.5 years, range: 20-83 years) treated with PUVA-therapy (42/92, 45%) or with nb-UVB (50/92, 55%) for 1-28 years (mean: 7.1 years). Among patients treated with PUVA, nine skin tumors (one melanoma, seven basal cell carcinoma (BCCs) and one squamous cell carcinoma (SCC)) were detected in 2/42 (4.7%) patients, while in the nb-UVB group, 14 skin tumors including two melanomas, four BCCs, and eight SCCs were diagnosed in 6/50 (12%) patients. Conclusions: A noteworthy number of NMSC were diagnosed in this Mediterranean population of patients exposed to high-dose UV treatment. A thorough risk-benefit evaluation should always be done before UV treatment and patients should be carefully monitored for skin cancer during and after treatment discontinuation.