Cervical intraepithelial lesions

Molly A. Brewer, DVM, MD, MS

Division of Gynecologic Oncology, University of Arizona, Arizona Cancer Center, Tucson, AZ 85724; Department of Gynecologic Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX, 77030; USA

The Pap smear has been responsible for the significant decrease in the incidence of cervical cancer over the last 40 years. Cervical cancer is a major health problem in underdeveloped countries where preventive health care is the exception rather than the rule. It is the second most common malignancy of women in the world with 470,606 new cases and 233,372 deaths in 2001 and accounting for 15% of all new cancers and 9% of all cancer deaths in women. In the United States, there will be an estimated 12,900 new cases of cervical cancer and 4400 deaths from this malignancy in 2001. Within the United States, racial and regional differences are attributed to varying exposures to risk factors and/or barriers to access for preventive health care. Diagnosis and treatment of lower genital tract squamous intraepithelial lesions (SIL) have undergone numerous changes over the last 25 years. Prior to the Pap smear, diagnosis most often occurred when large cancers of the cervix and vagina were observed incidentally because no screening test existed. Although development of the Pap smear has decreased the incidence of invasive cervical cancer among women with access to health care, it is still a major health problem, particularly in countries where access to preventive health care is limited. In addition, the false positive Pap smears have increased the cost of medical care to patients without an abnormality. Intraepithelial neoplasia (IEN) is well documented as a precursor lesion for cervical cancer, and treatment is ideally done prior to the development of cancer; however, controversies continue to exist regarding the management of these preneoplastic lesions. There is, as yet, no reliable way of differentiating lesions that will regress, lesions that will persist without regression and lesions that will progress to higher-grade dysplasia and ultimately to cancer. HPV testing is gaining new interest as being capable of predicting which Pap smears are associated with a high risk lesion and which lesions will progress, but the predictive value of HPV testing is still unclear. New methods of prevention are being tested in the United States with the use of HPV vaccines. Stimulating immunity to the human papilloma virus will hopefully decrease the incidence of IEN and subsequently cancer. New methods of interrogating the cervix are also being tested, particularly fluorescence spectroscopy. This technology has the potential of being developed into a real time diagnostic test. With further refinement, it will be more cost-effective than cervical cytology and may change the incidence of cervical cancer by increasing the diagnosis of IEN rather than advanced cervical cancer. Thus, the potential to prevent cervix cancer is within our grasp as new technology for prevention and diagnosis are being tested.

Paper presented at the International Symposium on Predictive Oncology and Intervention Strategies; Paris, France; February 9 - 12, 2002; in the section on Risk Assessment & Prognosis.