UVB phototherapy (UVBP) for the treatment of atopic eczema in adults does not increase the risk of cutaneous cancers, according to a retrospective analysis.
Published in the Journal of the American Academy of Dermatology, Taiwanese researchers retrospectively assessed whether UVBP use in adults with atopic eczema elevated the risk of cutaneous cancers.
The team undertook a nationwide, population-based cohort study from 2001-18 to estimate the risk of developing both non-melanoma skin cancer and melanoma. They excluded patients under 20 years of age, those with a prior diagnosis of skin cancer and individuals who had received PUVA therapy. The cohort of patients who had received UVBP were then matched 4:1 to a group of atopic eczema patients who had not received phototherapy.
The researchers calculated the number of UVBP sessions for each patient and adjusted their analysis for a number of covariates including immunosuppressant therapy.
Cutaneous cancer risk
After exclusion, a total of 1,241 patients in the UVBP group were matched to 4,964 patients in the non-UVBP group. For the entire cohort, mean age was 42.4 years and 65.8% were men.
Compared to those not receiving UVBP, there was no overall and significant increased risk of skin cancer in the phototherapy group (adjusted Hazard ratio, aHR = 0.91, 95% CI 0.35 – 2.35). Similarly, there was no increased risk of either non-melanoma skin cancer (aHR = 0.80, 95% CI 0.29 – 2.26) or cutaneous melanoma (aHR = 0.80, 95% CI 0.08 – 7.64).
In addition, the risk of either form of cutaneous cancer was not increased when analysed based on the number of UVBP sessions.
Understanding UVB phototherapy
UVBP is a recommended second-line treatment following failure of first-line treatment in patients with atopic eczema. While the existing literature suggests that longer-term use of UVBP does not increase the risk of cancer, this evidence is derived from patients with psoriasis. Consequently, whether this treatment modality is also safe in the longer term among those with atopic eczema remains uncertain.