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Introduction
Invasive cervical cancer is the second most common cancer in women worldwide, but 80% of cases occur in developing countries, (1) and although readily detectable in its pre-malignant stage, cervical cancer remains the fifth most common cancer in the UK (3). In 1998, it was reported that 12,800 women in the United States developed cancer of the uterine cervix, and 4,800 women died of the disease. (2). Cancer in general represents a major global health problem and has emerged recently as a health problem of increasing proportion in the UAE. (13). In 1991, cervical cancer deaths among females represented 6.4% of all death due to cancer in general. 20% of the deaths among UAE women was due to cancer of the cervix (13). In 1992, cervical cancer was the 4th in rank among the cancer deaths in females. Cancer of the cervix ranks sixth in cancer mortality in U.S. women. (4)
Cancer of the cervix refers to the invasine stage of the disease (international classification of diseases 180). Squamous cell carcinoma is the most frequent histological type of cervical caner. Adenocarcimona is less common and would seem less preventable by screening. Precancerous lesions are classified according to cytological and histological changes, which include dysplasia (CIN grades I-III) and carcinoma in site (CIS).
Known risk factors include early age at first intercourse and multiple sexual partners. A male consort who in turn has had intercourse with multiple women also confers a significant risk. Carcinoma of the cervix is more common in women who smoke. Also common in women who
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are immunosuppressed, especially those who have undergone renal transplantation, this may be mediated by the human papilloma virus
(HPV) (6). A case control study suggested that HPV does significantly increase the relative risk for developing cervical cancer. HIV infection may increase a women's risk for cervical
neoplasia. (6)
It is claimed that the vast majority of cervical cancers (theoretically up 90%) could be prevented if all women were offered and complied with high quality cytological screening
programmes. A national cervical screening programme was established in the United Kingdom in 1964. (8)
Pap smear screening has a specificity of approximately 99%, its better for high grade and invasive lesions. The test is less specific for low grade CIN over-diagnosis of these lesions is common, and is in part due to the tests inability to distinguish low-grade CIN from HPV infection. The sensitivity of pap smear screening has been reported to range from 40 to 70 percent. The generally accepted false negative rate is 15-25%. Due to the long period associated with the precursor lesion
(CIN), this false negative rate does not compromise screening strategies as long as smears are performed frequently enough. (6)
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