title: Mutagenicity and carcinogenicity of methoxsalen plus UV-A.
abstract: The combination of methoxsalen and long-wave UV radiation (UV-A) is being used on a large scale in clinical practice to treat a variety of dermatoses, particularly psoriasis. Theoretically, this combination may be mutagenic and carcinogenic, since methoxsalen binds covalently with DNA under the influence of UV-A. Mutagenicity has been studied in microorganisms and cell cultures. Arguments for possible carcinogenicity come from animal experiments and also from long-term follow-up studies of patients treated with psoralens and UV-A (PUVA). Transplantation studies in animals, allergic and irritative skin reaction experiments, and clinical observations indicate that PUVA also has an immunosuppressive effect. Short-term risk of skin cancer from PUVA therapy seems to be rather low if careful patient selection is made. However, for all patients, long-term maintenance treatment should be avoided as much as possible.
mesh_terms: D000818:Animals; D002273:Carcinogens; D006168:Guinea Pigs; D006801:Humans; D006968:Hypersensitivity, Delayed / Q000209:etiology; D007165:Immunosuppression Therapy; D066298:In Vitro Techniques; D008730:Methoxsalen / Q000009:adverse effects*; D051379:Mice; D009152:Mutagenicity Tests; D009153:Mutagens; D011701:PUVA Therapy / Q000009:adverse effects*; D010778:Photochemotherapy / Q000009:adverse effects*; D011565:Psoriasis / Q000188:drug therapy; D012306:Risk; D012878:Skin Neoplasms / Q000139:chemically induced; D012882:Skin Tests
chemical_list: D002273:Carcinogens; D009153:Mutagens; D008730:Methoxsalen