Cervical cancer is a highly preventable disease. Most cases are related to infection with human papillomavirus (HPV). Persistent cervical infection with high-risk, oncogenic HPV genotypes is necessary for the development of cervical cancer and its immediate precursor lesion, high-grade cervical intraepithelial neoplasia (CIN). Progression is generally slow and screening for cervical cancer has the potential to detect precancerous lesions and cancers in early stages, which can be effectively treated. Thus, in the United States, regular screening is recommended for all women between the ages of 21 and 65 years. Incidence and mortality rates for cervical cancer vary globally, depending on the availability of cervical screening and prevention programs. In the United States, which has widespread screening practices, there were more than 12,000 new cases of cervical cancer and 4,220 related deaths in 2011.
The screening tests currently used in the United States on cervical cell samples include the Papanicolaou (Pap) test to detect cellular changes, as well as tests for high-risk HPV genotypes. Although both tests identify a large proportion of women who harbor high-grade CIN, in a large number of women abnormalities detected on these tests will spontaneously resolve or will not be confirmed on histologic examination by colposcopy. A particular challenge is the management of women with test results of atypical squamous cells of unknown significance (ASCUS) or of low-grade squamous intraepithelial lesions (LSIL) on cytology or those with a normal Pap test but a positive test for high-risk HPV genotypes, since only a fraction of these women will have a finding on colposcopically directed tissue biopsy that warrants treatment. The median percentage of all Pap tests reported by various U.S. laboratories in 2009 for ASCUS ranged from 2.9 to 4.8 percent and for LSIL, from 1.2 to 2.8 percent, depending on the cytology preparation method (according to the College of American Pathologists Laboratory Accreditation Program). Less than one-fifth of women with these findings will have a finding on colposcopically directed biopsy that warrants treatment. Colposcopy incurs expense and may be associated with adverse events. Another complication of an ablative procedure is that on subsequent cervical cancer screening, if a screening test comes back abnormal, it can be difficult to visualize the lesion and allow the lesion to be optimally treated. Thus, testing strategies that can more accurately triage patients to colposcopy are needed, to minimize overtreatment. Tests being marketed and offered by some laboratories include in situ hybridization (ISH) tests to detect chromosomal abnormalities or HPV DNA.
This Technology Assessment (TA) examines the role of in situ hybridization (ISH) tests, including fluorescence ISH (FISH), to detect chromosomal abnormalities or HPV DNA on cervical cytologic specimens and their clinical validity for identification of precancerous lesions or cervical cancer.