Colposcopy: still useful in microbicide safety trials?

Colposcopy is used to evaluate vaginal microbicides, but its link to risk of HIV is unknown. This reanalysis of 9 safety studies determined the impact of omitting colposcopy on the number of findings detected and assessed whether colposcopy was useful in identifying nonoxynol-9 (N-9) as an unsafe product in one study.

Product-related findings seen with naked eye and colposcopy or by colposcopy alone were evaluated. Using data from one study, the ratio of findings in N-9 users to those in hydroxyethylcellulose (HEC) users was compared for findings seen by naked eye and colposcopy versus findings detected only by colposcopy.

Of the 403 finding observations in the 9 studies, 173 (43%) would have been missed without colposcopy. Data from the N-9/HEC study showed that without colposcopy, there would have been 7 times as many observations in the N-9 group as in the HEC group (63 vs. 9). With colposcopy, the N-9/HEC ratio was 13:9 or 1.4. Considering epithelial integrity, finding type, and size showed similar patterns, except that among the smallest findings (<5 mm), the N-9/HEC ratio was 1.2 by naked eye and nearly the same at 1.4 by colposcopy.

Colposcopy was not helpful in identifying an unsafe product: the conclusions reached using naked eye examination alone were more alarming regarding the safety of N-9 than reached by including colposcopy. Recommendations include: (1) naked eye examinations should be continued in 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.