A long-term prospective study of type-specific human papillomavirus infection and risk of cervical neoplasia among 20,000 women in the Portland Kaiser Cohort Study.

BACKGROUND

Human papillomavirus (HPV) DNA testing is more sensitive than cytology for detection of cervical intraepithelial neoplasia grade 3 and cancer (≥CIN3). Adding HPV testing to cytology is recommended for women ≥30 but long-term prospective studies of HPV testing are rare.

METHODS

Beginning in 1989-1990, ~20,000 women in a prepaid health maintenance organization (median age = 34) were followed passively by recommended annual cytology. We tested archived cervicovaginal lavage specimens collected at enrollment, primarily by MY09-MY11 PCR-based methods, for carcinogenic HPV types. We calculated positive and negative predictive values for the entire study period, and Kaplan-Meier estimates of cumulative probability for ≥CIN3, up to 18 years of follow-up.

RESULTS

We observed 47 cases of invasive cervical cancer during the study period, and 156 cases of CIN3. Predictive values and Kaplan-Meier analyses yielded the same conclusions. In women 30 and older, the reassurance against ≥CIN3 following a single negative HPV test was long-lasting (cumulative probability = 0.7% during follow-up). In this age group, a single HPV test (positive vs. negative, hazard ratio of 8.5, 95% CI = 4.8-15.1) provided greater long-term risk stratification than a single cytologic result (abnormal vs. normal, HR = 2.9, 95% CI = 1.2-6.6). The risk for ≥CIN3 was higher for HPV16 than for the average of the other carcinogenic types (hazard ratio = 2.7).

CONCLUSION AND IMPACT: The data from this cohort study show the long-term predictive value of HPV testing, particularly in women ≥30, and a possible role for distinguishing particularly carcinogenic types like HPV16.