Actinic keratosis (AK) is a common keratinocyte intra-epidermal neoplasia. To assess AK prevalence and potential risk factors in patients attending Italian general dermatology clinics. This retrospective study was conducted on clinical data from consecutive white outpatients aged ≥30 years, attending 24 general dermatology clinics between December 2014 and February 2015. AK prevalence (entire population) and multivariate risk factor analysis (patients with current/previous AK and complete data) are presented. AK prevalence in 7,284 patients was 27.4% (95% CI: 26.4-28.4%); 34.3% in men and 20.0% in women (p70 years), history of other non-melanoma skin cancers (OR: 2.7 [2.2-3.3]), residence in southern Italy/Sardinia (OR: 2.6 [2.1-3.0]), working outdoors >6 hours/day (OR: 1.9 [1.4-2.4]), male gender (OR: 1.7 [1.4-2.0]), facial solar lentigos (OR: 1.6 [1.4-1.9]), light hair colour (OR: 1.5 [1.2-1.8]), prolonged outdoor recreational activities (OR: 1.4 [1.2-1.7]), light eye colour (OR: 1.3 [1.1-1.6]), skin type I/II (OR: 1.3 [1.1-1.6]), and alcohol consumption (OR: 1.2 [1.0-3.3]). BMI ≥25.0 (OR: 0.6 [0.5-0.7]), regular sunscreen use (OR: 0.7 [0.6-0.8]), and a lower level of education (OR: 0.8 [0.7-1.0]) were independent protective factors. AK prevalence was high in Italian dermatology outpatients. We confirm several well-known AK risk factors and reveal possible novel risk and protective factors. Our results may inform on the design and implementation of AK screening and educational programmes.

Melanoma is the deadliest type of skin cancer characterized by high cellular heterogeneity, which contributes to therapy resistance and unpredictable disease outcome. Recently, by correlating reflectance confocal microscopy morphology with histopathological type, we identified four distinct melanoma subtypes: dendritic cell, round cell, dermal nest, and combined-type melanomas. In this study, each reflectance confocal microscopy melanoma subtype expressed a specific biomolecular profile and biological behavior in vitro. Markers of tumor aggressiveness, including Ki-67, MERTK, nestin, and stemness markers were highest in the most invasive combined-type and dermal nest melanomas than in dendritic cell and round cell melanomas. This was also confirmed in multicellular tumor spheroids. Transcriptomic analysis showed modulation of cancer progression-associated genes from dendritic cell to combined-type melanomas. The switch from E- to N-cadherin expression proved the epithelial-to-mesenchymal transition from dendritic cell to combined-type subtypes. The dermal nest melanoma was predominantly located in the dermis, as also shown in skin reconstructs. It displayed a unique behavior and a molecular profile associated with a high degree of aggressiveness. Altogether, our results show that each reflectance confocal microscopy melanoma subtype has a distinct biological and gene expression profile related to tumor aggressiveness, confirming that reflectance confocal microscopy can be a dependable tool for in vivo detection of different types of melanoma and for early diagnostic screening.

Background: Survivin is detected in few adult normal cells and it is highly expressed in cancer. Nuclear survivin facilitates cell cycle entry, whereas the mitochondrial pool protects cells from apoptosis. Survivin is overexpressed in keratinocyte stem cells (KSCs) and protects them from apoptosis. Methods: As KSCs are at the origin of squamous cell carcinoma (SCC), we evaluated survivin expression in normal and cancerous skin in vivo by immunohistochemistry and western blotting. HaCaT cells overexpressing survivin and wound-healing assay are used. Analysis of variance and Student’s T-tests are used for statistical analysis. Results: Survivin is localised in both the cytoplasm and nucleus of normal adult and young keratinocytes. Nuclear survivin is detected in one every 10 of 11 basal keratinocytes. When present in suprabasal cells, nuclear survivin is coexpressed with K10 but not with K15 or p75-neurotrophin receptor (p75NTR), a transit amplifying cell marker. Nuclear, but not cytoplasmic, survivin expression markedly increases in actinic keratosis and in SCC in situ, as compared with normal epidermis, and it is highest in poorly differentiated SCC. In SCC tumours, nuclear survivin-positive cells are mainly K10/p75NTR-negative and K15-positive. In poorly differentiated tumours, survivin mostly localises in the deep infiltrating areas. When overexpressed in keratinocytes, survivin increases cell migration. Conclusion: High survivin expression and the subcellular localisation of survivin correlate with keratinocyte differentiation and are associated with undifferentiated and more invasive SCC phenotype.