Squamous cell carcinoma (SCC) of the cervix is one of the most frequent female genital tract cancers, which causes a high level of malignancy-related mortality, affecting a large population worldwide. All of the effects of Human papilloma virus (HPV) infection, which is an important aetiological factor in the development of cervical carcinoma, remain to be clarified completely (1). Compared to studies focused on high risk HPVs in squamous cell carcinoma of the cervix, there are few studies about the mechanisms of carcinogenesis in cervical SCCs lacking HPV.There are about 40 subtypes of HPV affecting the genital tract, some of them have a high association with SCC of the cervix (2). Although more than 20 types of HPV have been found in these tumours, 4 types are responsible for more than 80% of cases (3, 4) and HPV 16 is the most frequent. HPV 16 and 18 are the most oncogenic and virulent types, and altogether are responsible for 70% of uterine cervix cancer (5, 6). Sexual intercourse is the main route of transmission of HPV infection; the frequency of HPV infection in different populations and countries varies widely (7). High risk HPVs, especially HPV 16 and 18, probably impose their early carcinogenesis effect by impairing the cell cycle through modulation of different genes' expression, including E6/E7 proteins (8). These early proteins, E6 and E7, bind and inactivate a tumoursuppressor gene product, p53, and the retinoblastoma tumoursuppressor protein, respectively. In cervical lesions caused by HPVs, the increased proliferation of suprabasal epithelial cells is attributed to the expression of the viral oncogenes, E6 and E7. E7 associates with Rb protein and other members of the pocket protein family, and disrupts the association Background: Human papillomavirus (HPV) infection is an important aetiological factor in squamous cell carcinoma (SCC) of the cervix. Limited studies have been focused on the differences between carcinogenesis of SCCs with and without HPV infection. Aims: The main goal of this study is to determine the expression of some of the apoptotic pathway regulators, including P53, Bax and Bcl2 in SCCs with and without high risk HPV 16/18 infection. Study Design: Cross sectional study. Methods: A total of 42 paraffin-embedded blocks with the histopathological diagnosis of invasive SCC with determined HPV 16/18 status were selected; half of them were HPV positive and the rest were negative. Afterwards, immunohistochemistry stained slides for p53, Bcl2 and Bax were evaluated with H-score, multiplicative and Additive Quick score by two pathologists; in cases of controversy about the results, the mean results were recorded.
Results:Mean results and percentage of expression of our three markers were significantly higher in the HPV 16/18 infected group than in uninfected individuals: Respectively, the mean score for Bcl2, Bax and p53 staining according to H-scoring method was 68.5, 234, 106.4 in the HPV 16/18 infected group and 4.5, 218.8, 5.07 in the uninfected group; and the Multiplicative Quick ...