title: Immunohistochemical Expression of Leptin in Non Melanoma Skin Cancer.
abstract: BACKGROUND
  Obesity in adults is associated with numerous health disorders including some forms of cancer. Various epidemiological studies have found a link between excess adiposity and malignant melanoma; however, the association with non melanoma skin cancer is questionable. Leptin is a hormone produced mainly by the adipose tissue and its serum level may reflect body mass index. Leptin is reported to promote proliferation and angiogenesis and deregulate apoptosis, therefore facilitates the process of carcinogenesis.
  
  
  OBJECTIVE
  The current study tried to assess leptin localization and expression in non melanoma skin cancer to verify its possible role in pathogenesis of this cancer.
  
  
  METHODS
  This study was carried out on 13 Basal Cell Carcinoma (BCC) cases and 14 Squamous Cell Carcinoma (SCC) cases together with 19 normal skin biopsies as a control group using immunohistochemical method.
  
  
  RESULTS
  Leptin was expressed in 52.6% of the normal epidermis with pure cytoplasmic and both cytoplasmic and nuclear staining patterns. All cases of SCC (100%) and two cases of BCC (15.4%) showed leptin expression in tumour cells whereas nuclear expression was in favour of SCC. Stromal expression of leptin was seen in both SCC (57.1%) and BCC (38.5%) without significant differences. Percentage of leptin expression by tumour cells in SCC showed positive linear correlation with tumour size (p=0.02) and microvessel density (p=0.000). Stromal expression of leptin in SCC was associated with large tumour size (p=0.04), advanced stage (p=0.01) and tumours arising in sites other than head and neck (p=0.01).
  
  
  CONCLUSIONS
  Leptin could have a more important role in pathogenesis of cutaneous SCC rather than BCC that may reflect the trivial role of obesity in induction of BCC. The expression of leptin by tumour and stromal cells of SCC could co-operate in its progression by promoting angiogenesis with subsequently acquiring large tumour size and then advanced stage.
authors.affiliation: Assistant Professor, Department of Dermatology and Andrology, Faculty of Medicine, Menoufia University , Egypt .
authors.forename: Azza G A
authors.initials: AG
authors.lastname: Farag
authors.affiliation: Lecturer, Department of Clinical Pharmacy, MSA October University , Egypt .
authors.forename: Nada Farag
authors.initials: NF
authors.lastname: Elnaidany
authors.affiliation: Lecturer, Department of Pathology, Faculty of Medicine, Menoufia University , Egypt .
authors.forename: Marwa Mohammed Serag
authors.initials: MM
authors.lastname: El-Dien
keywords: Basal cell carcinoma; Obesity; Squamous cell carcinoma