Photocarcinogenic risk of narrowband ultraviolet B (TL-01) phototherapy: early follow-up data

Conflicts of interest: none declared. Sir, We read with interest the article by Man et al.1 following on from their original notification.2 We too have recently compared all patients treated with narrowband ultraviolet UVB (TL‐01) in the dermatology department of Craigavon Area Hospital (a large regional hospital in Northern Ireland) against the Northern Ireland Cancer Registry. Since 1993, 484 patients have received at least one course of TL‐01 UVB (a course being ≈ 18 treatments) for a variety of skin disorders including psoriasis, eczema and polymorphic light eruption, the majority being for psoriasis. Levels of cancer in these patients were verified by the Northern Ireland Cancer Registry, a 'population‐based registry (1·7 million) which receives data electronically from multiple sources including all pathologically diagnosed skin cancers'. Levels of cancer in the cohort of patients were as expected for rates in the general population. Four patients were found who cross‐referenced with the register; of these none had developed skin cancer although one patient was identified who had received TL‐01 UVB as treatment for pre‐existing mycosis fungoides. The three remaining cases were unrelated: two cases of carcinoma in situ of the cervix and one hydatidiform mole of pregnancy. Both conditions were present before TL‐01 UVB therapy. The rates of skin cancer in Northern Ireland (figures obtained from the Northern Ireland Cancer Registry) are shown in Table 1.