Anatomical distribution and demographic features of head and neck non-melanoma skin cancers

PURPOSE: Non-melanoma skin cancer (NMSC) is the most commonly diagnosed cancer worldwide. NMSC predominantly affects the head and neck, with over 80% of cases arising in this region. This study aimed to investigate the differences in anatomical distribution, epidemiological and histological characteristics of NMSC in a Caucasian population. MATERIALS AND METHODS: A retrospective analysis was conducted of 556 primary head and neck NMSC treated at a referral centre between January 2016 and December 2021. Relative tumour density (RTD), BCC/SCC ratio, and Chi-square test were used for skin tumour analysis. RESULTS: The RTD was highest on the nose (RTD 11.24, 95% CI 9.6-12.8) for basal cell carcinoma (BCC), on the ear and periauricular area (RTD 4.79, 95% CI 3.56-6.02) for squamous cell carcinoma (SCC), and on the cheek/cheekbone area (RTD 10, 95% CI 5.52-15.51) for SCC in situ. The total ratio BCC/SCC ratio was 2.69/1 (95% CI 2.5-2.87). The highest BCC/SCC ratio was found on the nose (6.35/1, 95% CI 5.81-6.88), while the lowest ratio on the scalp (0.4/1, 95% CI 0-3.81). Chi-square analysis revealed significant associations (p < 0.05) between histologic type with primary anatomic site, age distribution, sex, and depth of invasion (DOI). At the time of diagnosis, SCC tumours were significantly larger than BCC, with mean diameters of 13.45 mm and 9.38 mm, respectively. CONCLUSIONS: The analysis showed statistically significant differences in clinical presentation between BCC, SCC and SCC in situ in the head and neck region. These findings may guide clinical suspicion and therapeutic decisions during patient evaluation.