Total Skin Electron Irradiation and Sequential Malignancies in Mycosis Fungoides Patients: Longitudinal Study

Abstract

The purpose of this study was to determine the role of total skin electron irradiation (TSEI) as a cause of second malignancies in mycosis fungoides (MF) patients. Mycosis Fungiodes patients referred to Total Skin Electron Irradiation were followed in a longitudinal study. Other diagnosed malignancies were obtained after cross-matching with the Israel National Cancer Registry database. Between 1970 and 2010, 197 patients were treated; 134 (68%) males, 63 (32%) females; mean age 58±17years. Topical/systemic treatment was given to 134 (68%) patients. TSEI was given to 104 (68.9%) patients. Seven (4.6%) received sub-TSEI and 40 (26.5%) received focal electron irradiation fields. Forty-six (23%) patients did not receive radiotherapy. Second primaries rate was 6.7 times higher in male MF patients and 13.1 times higher in female MF patients than in the general Israeli population. Malignant melanoma developed in eight patients after radiotherapy, in one patient without irradiation. Skin-related cancers rate after irradiation versus no irradiation was higher (p=.011). Combination radiotherapy with psoralen+UVA and/or nitrogen mustard yielded 11 cases of skin cancer vs no case without irradiation. MF patients have a high incidence of sequential malignancies. TSEI is associated with higher "skin-related cancers" rates. Close longitudinal follow-up of MF patients is obligatory.