Biomarkers & Adherence

Colposcopy

Colposcopy is a diagnostic procedure developed in the 1920s that uses a special lighted microscope, the colposcope, to inspect vulvar, vaginal, and cervical surfaces by visualizing and magnifying them.   The vulva is examined for suspicious lesions, and then a vaginal speculum is inserted into the vagina to allow for visualization of the vagina and cervix.

Colposcopy is primarily used to aid in the diagnosis of precancerous and cancerous lesions to combat cervical cancer, but it is also used as a tool to assess the safety of vaginal products, including microbicides. CONRAD and the World Health Organization (WHO) have standardized a set of colposcopy procedures to assess the safety of vaginal products; the CONRAD/WHO Manual for the Standardization of Colposcopy for the Evaluation of Vaginal Products describes colposcopy’s assessment roles, lists appropriate steps to use when analyzing new vaginal products, and provides standard terminology for findings, photographs, and a sample data collection form.

The rationale for the use of colposcopy in safety assessments of new vaginal products is that it can help identify small epithelial changes that could signify risks in acquiring sexually transmitted infections that might not be seen with the naked eye. There is some disagreement, however, about the usefulness of colposcopy in safety trials because the procedure requires additional time and training, is dependent on examiner effort, and most importantly, has not been shown to identify lesions that signify an increased risk of HIV infection. To address this, CONRAD and FHI researchers analyzed nine vaginal product safety studies that included both naked eye examination and colposcopy to determine if colposcopy was useful in assessing the safety of candidate microbicides. Only one of the studies included both a product that is known to cause epithelial damage and increase the risk of HIV transmission when used frequently (nonoxynol-9) and a product that is known to be safe (HEC placebo). Analysis of this study showed that colposcopy did not provide any clear warning about nonoxynol-9 beyond that provided by naked eye examination alone. In light of these findings, recommendations for future microbicide studies include the following: 1) naked eye examinations should be continued in all microbicide studies; 2) colposcopy may be considered for early studies, such as first-in-human studies, but has no place in large studies; and 3) colposcopy should be replaced as soon as possible with a more objective, validated biomarker of HIV risk that can be used to help triage products.  



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