Immunohistochemical assessment of p16, COX-2 and EGFR in HPV-positive cervical squamous intraepithelial lesions.

The protein capsid L1 of the human papilloma virus (HPV) - a key factor in the cervical carcinogenesis - is considered, together with p16, EGFR and COX-2, a characteristic marker for the evaluation of the malignancy progression and prognostic, in terms of tumoral aggressiveness. The purpose of the present study was to make a comparative assessment between the immunohistochemical pattern of p16, EGFR and COX-2 and immunochemical expression of L1 HPV capsid protein, in low grade and high-grade cervical squamous intraepithelial lesions, in order to determine the relationship of these tumoral markers with the infection status of HPV, and their practical applicability in patients diagnosis and follow-up. The study group included 50 women with cytological and histopathological confirmed LSIL (low grade SIL) and HSIL (high-grade SIL). The immunoexpression of L1 HPV protein was assessed on conventional cervico-vaginal smears and EGFR, COX-2 and p16 were immunohistochemically evaluated on the corresponding cervical biopsies. From all cervical smears, the HPV L1 capsid protein was expressed in 52% of LSIL and 23% of HSIL. From all cervical biopsies, p16 was positive in 64% of LSIL, 82% of CIN2 and 100% of CIN3, EGFR was overexpressed in 67% of HSIL (56% CIN2 and 43% CIN3) and 32% LSIL. For COX-2, the Allred score was higher in HSIL when compared to LSIL. Our data revealed 33 cases belonging to both LSIL and HSIL categories with the same Allred score. Immunochemical detection of L1 capsid protein, on cervico-vaginal smears, indicates an immune status induced by the HPV infection and may offer prognosis information, mainly in LSIL lesions. The assessment of p16, EGFR, and COX-2 allows to an integrative approach for the progression of squamous intraepithelial lesion, associated or not with the HPV infection.