Background HPV infection and cervical cancer are often found at the cervical transformation zone. High rates of HPV in adolescents have been attributed to their greater extent of “cervical ectopy”, defined as areas of columnar and metaplastic epithelium visible on the ectocervix. The study aim was to examine associations between the extent of cervical ectopy and incident HPV infection in healthy adolescents.

Methods Sexually active young women were enrolled as part of a prospective HPV Natural History Study. Women were eligible if they were 13–21 years old, sexually active (5 years maximum), and had no history of cervical intraepithelial neoplasia, cervical procedures, or immunosuppression. At 4-month interval visits, we performed colpophotography to document the epithelium, HPV testing for 37 types by Roche Reverse Line Blot assay, and interviews to assess behaviours. This study selected women (N=147) who had negative HPV results at the first two consecutive visits. Epithelial areas of interest were measured in the digitised colpophotographs by using computerised planimetry to produce pixel counts. The extent of ectopy was measured as a percentage of the total cervical face. Cox proportional hazards models examined ectopy as a predictor for incident HPV, defined as the first positive HPV result following the initial two negative results, adjusted for the number of new sexual partners. Outcomes included incidence of any HPV type; α-9 HPV types (defined as 16, 31, 33, 35, 52, 58, 67); and a-3/15 HPV types (defined as 61, 71, 72, 81, 83, 84, 89).

Results The 147 women attended a total of 545 visits. The mean age at baseline was 17.2 years, mean age of menarche was 12.8 years, and mean age of first sex was 15.4 years. Self-reported race/ethnicity was 35 (24%) Asian, 14 (10%) African-American, 43 (29%) Caucasian, 52 (35%) Latina, and 3 (2%) Other. The median ectopy measurement from the 545 visits was 14% (interquartile range 6–32%) of the total cervical face. Incident HPV of any type was found in 42 (29%) women. The extent of ectopy was not significantly associated with incidence of any HPV type (HR 1.004, p=0.63); α-9 HPV types (HR 0.99, p=0.43); or α-3/15 HPV types (HR 1.02, p=0.18). Results were unchanged when adjusted for new sexual partners in the past 8 months (HR 1.9, p<0.01).

Conclusions When measured quantitatively, the extent of cervical ectopy is not a risk factor for the acquisition of HPV infection in healthy adolescent women.