Acta Dermato-Venereologica 99-10CompleteContent | Page 11

878 CLINICAL REPORT Sunbed Use Increases Cutaneous Squamous Cell Carcinoma Risk in Women: A Large-scale, Prospective Study in Sweden Gustav Boelsgaard CHRISTENSEN 1 , Christian INGVAR 2 , Linda Werner HARTMAN 3 , Håkan OLSSON 4 and Kari NIELSEN 5 1 Department of Dermatology, Skåne University Hospital, Department of Clinical Sciences, Dermatology and Venereology, 2 Department of Surgery and 4 Department of Oncology and Pathology and Cancer Epidemiology, Skåne University Hospital, Department of Clinical Sciences, Lund University, 3 Faculty of Medicine, Department of Clinical Sciences, Oncology and Pathology, and 5 Department of Dermatology, Helsingborg Hospital, Department of Clinical Sciences, Dermatology and Venereology, Lund University, Lund, Sweden The incidence of cutaneous squamous cell carcinoma has increased rapidly in Sweden in the past decades. Here, we present a prospective study of the Melanoma in Southern Sweden (MISS)-cohort, with 29,460 parti- cipating women in southern Sweden that investigates the risk factors for cutaneous squamous cell carcino- ma. Data on the host and skin cancer risk factors were collected through questionnaires and then matched with the National Cancer Registry. Statistical analyses were based on uni- and multivariable Cox proportio- nal hazards models, using age as the time-scale. We found that sunbed use (hazard ratio (HR) 1.2, 95% CI: 1.1–1.4), red and light blond hair (HR 1.6, 95% CI: 1.1–2.3), freckles (HR 1.4, 95% CI: 1.1–1.8) and immunosuppressive medications (HR 2.1, 95% CI: 1.3–4.5) were independent risk factors. Furthermore, we observed a dose-dependent relationship between sunbed use and the development of cutaneous squa- mous cell carcinoma. Our findings support the idea of integrating dermatological follow-up examinations for immunosuppressed patients and banning the use of sunbeds in order to prevent cutaneous squamous cell carcinoma. Key words: cutaneous squamous cell carcinoma; risk factors; sunbed; prospective cohort. Accepted Apr 16, 2019; E-published Apr 16, 2019 Acta Derm Venereol 2019; 99: 878–883. Corr: Gustav Boelsgaard Christensen, Department of Dermatology, Skå- ne University Hospital, Lasarettsgatan 15, SE-222 41 Lund, Sweden. E- mail: [email protected] O ver the past 10 years, there was an annual increase of 6.5% for Swedish women and 5.5% for Swe- dish men in the incidence of cutaneous squamous cell carcinoma (cSCC), making it the most and second most rapidly increasing malignant tumour in Sweden (1, 2). This trend has been observed for light-skinned people worldwide as well (3–6). A cSCC diagnosis can be lethal and surgical excision is the first line treatment in forms of invasive cSCCs. A patient with the suspected diagnosis is often referred from primary care to a dermatology department for diagnosis and subsequent treatment. Due to the rise in incidence, the number of patients in derma- tology departments has been increasing, which represents a growing economic burden on the healthcare system. doi: 10.2340/00015555-3198 Acta Derm Venereol 2019; 99: 878–883 SIGNIFICANCE There has been an increase in the number of skin cancers in Sweden in the last decades. We looked closer at one skin cancer in particular – squamous cell carcinoma. In order to be able to prevent squamous cell carcinoma, we need to understand which risk factors are most important. We studied a large group of Swedish women and looked into which risk factors play a role in getting squamous cell car- cinoma. Having freckles and red or light blond hair, taking medications that suppress the immune system and using sunbeds play a part. As with most cancers, the interaction between phenoty- pic, genotypic, and environmental factors determines the individual risk for developing cSCC. As such, understan- ding these risk factors and implementing evidence-based preventive strategies are essential to combat the rising incidence of cSCC. Analysing risk factors identified in prospective studies with no recall bias, can help to achieve this goal. The majority of the studies, examining risk factor contribu- tion to cSCC, to date are retrospective in nature and very little focus exclusively on women. In contrast, the aim of the present study is to prospectively investigate a cohort of women and thereby elucidate the influence of both phenotypic (colour of hair and eyes, freckles and naevi count) and environmental factors (medicine intake, educational level, smoking habits and UV exposure) on cSCC incidence. MATERIALS AND METHODS Participants The MISS (Melanoma in Southern Sweden) cohort was established in 1990–1992 and is still followed prospectively. Swedish-born women (1,000 women per calendar year, born between 1925 and 1965), living in the Southern Sweden’s health care region, with no prior diagnosis of invasive cancer were selected for the study. The women included in the cohort were chosen through random computerized selection from the Population/Census Registry and were controlled to have no prior diagnosis of invasive cancer through the Regional Cancer Registry before the final inclusion. At baseline 40,000 women were included into the study. Non- responders were sent a reminder letter. The invited women were asked to answer a written questionnaire on the possible risk factors for skin cancer and breast cancer. The This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2019 Acta Dermato-Venereologica.