Determination of skin cancer frequency and evaluation of risk factors in patients applying to Karadeniz Technical University Faculty of Medicine Dermatology outpatient clinic

Objective: Skin cancers are the most common type of cancer in the world and its incidence is increasing significantly every year. Skin cancer incidence data in our country are quite limited and were obtained from retrospective data. In our study, we aimed to reveal the one-year incidence of skin cancers (cutaneous squamous cell carcinoma, basal cell carcinoma and malignant melanoma), sociodemographic characteristics of these patients and risk factors for skin cancer. Materials and Methods: All patients and their relatives who applied to the Department of Dermatology and Venereal Diseases and gave consent to participate in the study by filling out a questionnaire were included in the study. Height, weight, body mass index, cigarette-alcohol use, tea-coffee consumption of individuals who gave consent to the study were recorded. Known chronic diseases (hypertension, diabetes mellitus, hyperlipidemia, cardiovascular disease, hypo-hyperthyroidism, history of cutaneous and extracutaneous malignancy, organ transplantation), supplemental drug and vitamin D use, sun protection habits and diet were evaluated. Lesions with clinical suspicion of skin cancer were excised and sent to pathology. Skin cancer type, lesion duration, size and location, presence of symptoms such as pain, itching-burning, etc., and histopathological features of patients who were clinically and histopathologically diagnosed with cutaneous squamous cell carcinoma, basal cell carcinoma or malignant melanoma were recorded. Results: 7396 people were included in our study, of which 4324 (58.5%) were female and 3072 (41.5%) were male. The age range was between 1 and 96 years and the mean age was 37.18±2 years. A total of 200 patients diagnosed with new skin cancer were identified and constituted 2.7% of the population. Basal cell cancer(BCC) was detected in 89 patients (1.2%), squamous cell cancer(SCC) in 85 individuals (1.1%), and malignant melanoma(MM) in 33 patients (0.4%). Seven patients had more than one type of skin cancer. The mean ages were 64.2 (±13.8), 75.04 (±12.2) and 62.85 (±20) years for BCC, SCC, and MM, respectively. Considering the distribution of age at diagnosis, the majority of the patients in our study were 61-80 years old. Skin cancer was detected in only one person aged 20 years and younger. When compared with the control group, it was determined that having a history of smoking in the past was a risk factor for BCC (p=0,024), SCC (p<0,001) and MM (p=0,002); and history of alcohol use was a risk factor for BCC(p<0,001) and SCC(p<0,001). Those who had a history of alcohol use and quit had a 13-fold higher risk of developing SCC than those who currently use alcohol (OR: 13,782 (95% CI: 3,636-52,244). In our study, when compared to the control group, daily tea consumption was observed as a risk factor for BCC (p=0,021), SCC(p=0,006) and MM(p=0,002). Compared to the control group, daily coffee consumption was determined as a protective factor for SCC(p<0,001) and MM(p=0,049); however, such a difference was not observed in BCC (p=0,214). While vitamin D and supplemental drug intake were observed as protective factors for BCC (p=0,035, p=0,007, respectively), both were not observed as protective factors in SCC and MM patients. When compared with control group, obesity (BMI≥30) was observed as a risk factor for BCC(p=0,005) and MM(p:0,008), but no significant difference was observed in patients with SCC (p=0,965). In our study, there was no statistically significant difference between the ages of BCC, SCC, and MM in obese and non-obese individuals, and no correlation was found between obesity and the age of onset of skin cancer. When compared with the control group, having extracutaneous cancer is a risk factor for BCC (p<0,001) and SCC (p=0,001); There was no difference between hematological and solid organ cancers. No such relationship was found for MM (p=1). In our study, when risk factors independent of age were evaluated in the regression analysis, having a history of alcohol use and the absence of supplemental drug use was found to be significant as an independent risk factor for BCC (OR: 9,219 (95% CI: 2,511-33,855); OR: 5,906 (95% CI: 1,377- 25,328)). A history of alcohol use, regular drug use, and BMI <30 were found to be significant as independent risk factors for SCC (OR: 4,794 (95% CI: 1.213-18.954); OR: 2,144 (95% CI: 1,054-4,358); OR: 1,802 (95% CI: 1,005-3,231)). A history of alcohol use and regular drug use were found to be significant in the regression analysis, as independent risk factors for MM (OR: 14,371 (95% CI: 2,306-89,569); OR: 4,689 (95% CI: 1,516-14,504)). Conclusion: In our study, having a history of alcohol use was associated with a 9.2-fold increased risk for BCC, 4.8-fold for SCC, and 14.4-fold for MM compared to those who had never used alcohol. Regular drug use is associated with a 2.1-fold increased risk for SCC and a 4.7-fold increased risk for MM. No use of supplements 5.9-fold increased risk of BCC; A BMI <30 is associated with a 1.8-fold increased risk of SCC. Considering the results obtained in our study, it is clear that larger studies are needed to reveal the risk factors in patients with skin cancer.