p53 Protein expression in squamous cell carcinomas from sun-exposed and non-sun-exposed sites.
BACKGROUND
In sun-exposed nonmelanoma skin cancers, observation of specific p53 gene mutations implicate the role of UV radiation-induced mutations in the pathogenesis of these tumors. Immunohistochemical p53 protein overexpression and p53 gene mutation have been frequently considered related events.


OBJECTIVE
We investigated the differences in p53 immunostaining in squamous cell carcinomas (SCCs) with varying degrees of differentiation, from both chronically sun-exposed and sun-protected sites of the skin.


METHODS
Twenty-six SCCs (15 UV-related and 11 UV-unrelated) and five specimens of Bowen's disease (in situ SCC) from sun-exposed skin were examined by means of BP53-12-1 monoclonal antibody immunohistochemistry.


RESULTS
p53 Immunoreactivity was observed in 66.7% of sun-exposed, 54.5% of non-sun-exposed invasive SCCs (Fisher's exact test, p = 0.689), and 80% of Bowen's disease specimens. In 50% of all samples, p53 positivity was more prominent in the proliferating periphery of the tumor with gradual loss of positivity as the cells differentiated.


CONCLUSIONS
The reliability of p53 immunohistochemistry needs further molecular genetic studies.
Oram
Y
Y
Department of Dermatology, Baylor College of Medicine, Houston, TX.
Orengo
I
I
Baer
S C
SC
Ocal
T
T
D000328:Adult; D000368:Aged; D001913:Bowen's Disease / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D012878:Skin Neoplasms / Q000378:metabolism*; D013472:Sunlight; D016159:Tumor Suppressor Protein p53 / Q000032:analysis*
D016159:Tumor Suppressor Protein p53