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Overview and Lessons Learned - Cervical Cancer Program Examples - Cervical Cancer Bibliography - Cervical Cancer Links - Cervical Cancer
Cervical Cancer Forum Presentation Materials - Cervical Cancer Glossary - Cervical Cancer
Research Topics - Cervical Cancer

Research Topics

This section provides brief summaries of some of the major research areas related to cervical cancer control in low-resource settings. More detailed discussions of specific research topics are included in the bibliography

Epidemiology and natural history of cervical cancer in various settings

Role of HPV tests and possible HPV vaccines in cervical cancer control

Primary prevention of cervical cancer

Assessment of alternative screening approaches

Evaluation of simple treatment approaches

Client perceptions of cervical cancer and prevention approaches

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Epidemiology and natural history of cervical cancer in various settings, including the role of HPV.

Much recent research has focused on identifying HPV types from women with cervical dysplasia and cancer in many regions. This research suggests that HPV likely is the cause of most cervical cancer worldwide (Pisani et al., 1997 and Hernandez-Avila et al., 1997) . Traditional research on risk factors for cervical cancer also continues. Besides HPV, other often cited risk factors include certain sexual activity patterns (Biswas et al., 1997) and smoking (Prokopczyk et al., 1997, Roteli-Martins et al., 1998). In many developing countries, there is concern among clinicians that cervical cancer develops differently than traditionally described in Western countries, including that cervical cancer develops at younger ages and that dysplasia progresses more quickly to invasive disease. Few studies have yet demonstrated this conclusively, however.

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Role of HPV tests and possible HPV vaccines in cervical cancer control.

To date, no study has yet identified a broadly acceptable protocol for using HPV testing as part of a cervical screening or treatment strategies. In general, proposed approaches such as administering HPV tests to women with mild dysplasia as a means of determining whether treatment is necessary have had varying levels of effectiveness and are likely to be relatively costly (Bollen et al., 1997 and Kaufman et al., 1997). Prospects are hopeful for the utility of HPV vaccines, however. Although commercial vaccines are unlikely to be available for some years, and their impact on cervical cancer rates would not be measurable for years after their introduction, they have the potential to sharply reduce cervical cancer rates in the next century.

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Primary prevention of cervical cancer

Although primary prevention of human papillomavirus (HPV) infection would greatly reduce cervical cancer mortality, the prevention of HPV presents greater challenges than most other STDs. HPV is generally asymptomatic and is easily transmitted. The virus can exist throughout most of the anogenital area (including areas not covered by male condoms). While there are available treatment strategies for the genital warts sometimes caused by HPV, no therapies exist to eliminate the underlying infection (Koutsky et al., 1999; PATH, 1998). It is not clear whether barrier methods of protection against STDs are effective in protecting women from cervical cancer. A number of studies have found barrier methods to be protective ( Grimes et al., 1995; Slattery et al., 1989; Cooker et al., 1992), but others do not support this as an effective method of prevention of cervical cancer (Hildesheim et al., 1990; Celetano et al., 1987). Certainly, sexual abstinence or lifetime mutually monogamous relationships would prevent the transmission of HPV, however, these options are not realistic for most individuals. Other suggestions of primary prevention strategies for cervical cancer are based on risk associations in case-control studies and include avoidance of cigarette smoking and high dietary intake of vitamin C (Grimes et al., 1995). Both the World Heath Association and the National Institute of Health also recommend sex education and efforts to change sexual behavior as part of their primary prevention strategies (WHO, 1985; NIH Consensus Statement, 1986). 

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Assessment of alternative screening approaches

Pap smears can be an effective screening tool, but uneven quality can present problems. Also, high specificity can not be achieved without reducing sensitivity. The WHO Reproductive Health Library includes a summary of a meta-analysis of Pap test accuracy that reviewed 62 studies and concluded that, "the Pap test may be unable to achieve concurrently high sensitivity and specificity (Fahey, 1995)." Studies of a number of new cervical cancer screening approaches -- including visual inspection, automated Pap screening, and Pap screening incorporating HPV tests are ongoing. Of particular interest in low-resource settings are studies to assess the accuracy and acceptability of visual screening as a means of detecting cervical dysplasia and/or cancer. The term visual inspection (VI) has been used to refer to simply examining the cervix for obvious lesions often cancerous (Nene et al., 1996 and Wesley et al., 1997). Visual inspection with acetic acid (VIA) is being used to describe looking at the cervix after treatment with acetic acid to identify acetowhite lesions: visual inspection with acetic acid and low-power magnification (VIAM) also is being investigated. In some settings, visual inspection after acetic acid application may work at least as well as Pap smears. A recent study in India found VIA to be slightly more accurate than Pap smears in that setting (Sankaranarayanan et al., 1998). A recent study in Zimbabwe found that, in primary health care settings, VIA was more sensitive in detecting high-grade dysplasia than Pap smears, but less specific ( UZ/JHPIEGO, 1999). Other studies of various screening approaches, including in South Africa and Mexico, are ongoing; RHO will report on study results as soon as they are available.

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Evaluation of simple treatment approaches

There are two outpatient dysplasia treatment approaches that have demonstrated utility in low resource settings. These are cryotherapy (freezing of diseased tissue through application of a refrigerated probe) and LEEP (loop electrosurgical excision procedure which uses a thin, electrified wire to excise cervical lesions). These methods have been found to have comparable rates of successes and complications (Mitchell et al., 1998). An area of current research interest is whether these approaches can be used in a "see and treat" strategy, in which a client is diagnosed with dysplasia either through a Pap smear, visual screen, or colposcopic exam, and then treated immediately to remove dysplastic tissue. (Megevand et al., 1996 ).

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Client perceptions of cervical cancer and prevention approaches

Research on how clients and providers perceive cervical cancer and what influences women to seek out cervical cancer interventions is crucial to the success of cervical cancer prevention programs. Many studies show that women in developing and other underserved populations do not have a good understanding of cervical cancer or available services. Studies also show that providers are in need of both effective technical training in cervical dysplasia screening/treatment and training in educating and counseling clients at risk of cervical cancer (PATH, 1996; Strickland et al., 1996.)

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Overview and Lessons Learned - Cervical Cancer Program Examples - Cervical Cancer Bibliography - Cervical Cancer Links - Cervical Cancer
Research Topics - Cervical Cancer Cervical Cancer Forum Presentation Materials - Cervical Cancer Glossary - Cervical Cancer