Studies have shown a strong association between solar irradiance and an increased risk of NMSC (non melanoma skin cancers). Solar irradiance is an essential requirement for adequate endogenous vitamin D formation and is critical for epidermal health. On the other hand unprotected and excessive sun exposure is the most significant risk factor for development skin cancers such as NMSCs. The inhibition, by vitamin D, of various cancers in in vitro and in vivo models has triggered detailed investigation of vitamin D effects on neoplastic behaviour. Very little is known about vitamin D influence on NMSCs and its potential protective effect against cutaneous carcinogenesis is still poorly understood.
Significance of study
The significance of this study is to better understand vitamin D involvement in prevention of cutaneous carcinogenesis. The histological examination of vitamin D metabolic and tumour markers in cutaneous neoplastic lesions (particularly basal cell carcinoma (BCC), squamous cell carcinoma (SCC), actinic keratosis (AK) and squamous cell carcinoma in situ(SCC in situ)) allows a correlation of vitamin D metabolism and tumour regulatory proteins.
14 BCC, 11 AKs, 9 SCC in situ and 8 SCC surgical excision specimens from patients aged 41 – 93, were a generous gift of Prof. Sinclair (Department of Dermatology, St-Vincent’s Hospital). Tissue sections were immunohistochemically assessed using immunoperoxidase method. The expression of tumour markers and vitamin D enzymes and receptor (VDR) was examined.
The results of this study show that vitamin D metabolism is compromised in skin tumours from patient with NMSC and may influence tumour growth and development. The cutaneous expression of tumour markers (EGF, FGFR3, FGF3, EGFR and VEGF) was analysed and correlated with cutaneous expression of vitamin D enzymes (CYP27A1, CYP27B1, CYP24) and receptors (VDR).
This study indicates that poor expression of vitamin D enzymes and VDR are associated with overexpression of tumour markers and more aggressive cutaneous carcinogenesis.