Many patients with vitiligo undergo multiple courses of phototherapy, which may raise concerns about their risk of photocarcinogenesis. Previous studies have pointed to ultraviolet (UV) light as a cause of skin cancers, including melanoma.1,2 But a new study that examined long-term narrowband UV-B (NBUVB) phototherapy in Korean patients with vitiligo suggests that the treatment is not linked to an increased risk of skin cancer in this population.3
“Our data suggested that NBUVB phototherapy appears to be safe for patients with vitiligo in terms of the development of skin cancer,” the authors wrote in their paper.
In the study, researchers looked at data posted in the Korean national health insurance claims database between January 1, 2007, and December 31, 2017. The researchers identified 60,321 patients with vitiligo. Of all the patients, 20,105 had not undergone NBUVB phototherapy, 20,106 had received fewer than 50 sessions, and 20,110 had received 50 or more sessions of NBUVB phototherapy during the study period. Of the patients who had undergone more than 50 sessions, 9702 had received between 50 and 99 treatment sessions, 6226 had received between 100 and 199 treatment sessions, and 4182 patients had received 200 or more sessions.
The researchers looked at the incidence of actinic keratosis, Bowen disease, nonmelanoma skin cancer, and melanoma among study participants. They assessed whether NBUVB phototherapy was tied to an increased risk for any of these conditions using univariable and multivariable Cox proportional hazards regression models.
The authors did not find a significant increase in the risk of actinic keratosis among patients who had received fewer than 50 sessions of NBUVB phototherapy (hazard ratio [HR], 0.940; 95% CI, 0.662-1.336), those who had received 50 to 99 sessions (HR, 0.751; 95% CI, 0.467-1.209), or those who had received 100 to 199 sessions (HR, 1.413; 95% CI, 0.921-2.168), compared with those who had not received the therapy.
Those patients who had received 200 or more sessions of NBUVB phototherapy did have a significantly greater risk of actinic keratosis (HR, 2.269; 95% CI, 1.530-3.365) compared with those who had not received the therapy. Moreover, for patients aged 20 to 49 years, the risk of the condition was significantly greater in those who had received 100 to 199 sessions of NBUVB phototherapy (HR, 5.759; 95% CI, 1.054-31.451), and those who had received 200 or more sessions (HR, 20.529; 95% CI, 4.488-93.915).