Does the risk of basal cell carcinoma increase in patients with psoriasis under treatment?

Background: Psoriasis is a common, chronic, inflammatory disease. Although it mainly affects the skin, it has been associated with a large number of comorbidities. In addition to comorbidities such as depression and psoriatic arthritis, it is known that there is an increased prevalence of cancer in psoriasis patients. Skin cancers, particularly squamous cell carcinoma, have been associated with psoriasis. However, basal cell carcinoma data are limited. Methods: 346 psoriasis patients and 306 individuals were selected as the control group. There were no differences between the patient and control groups in terms of age and gender. The mean age of the psoriasis patients was 49.9 +/- 15.8 years and the control group was 49.4 +/- 13.4 years. Sociodemographic data of the patients were recorded. Pharmacological agents used in the treatment of psoriasis were included in the analysis. Disease severity was assessed by the psoriasis area severity index (PASI). In the physical examination of the patients, biopsies were taken from lesions suspicious for BCC. BCC diagnosis was made by histopathologically. Results: The frequency of BCC was higher in psoriasis patients than in the control group (6.6% vs. 2.9%, p < .001). Advanced age (p < .001), smoking (p = .003), and arthritis (p < .001) were associated with BCC in psoriasis patients. However, there was no relationship between PASI and BCC (p = .142). Among the psoriasis treatments, only UV therapy was associated with BCC (p = .038). The frequency of PUVA (p < .001) and number of PUVA session (p = .010) was higher in psoriasis patients with BCC rather than NB-UVB. Conclusion: The frequency of BCC is increased in psoriasis patients. Psoriasis is associated with an increased risk of BCC, especially when treated with PUVA therapy for a long time.