Aptima HPV Assay versus Hybrid Capture ® 2 HPV test for primary cervical cancer screening in the HPV FOCAL trial.

BACKGROUND: Cervical cancer screening programs are switching from Pap screening to high-risk HPV testing.

OBJECTIVES: To compare the Aptima HPV Assay (AHPV) with the Hybrid Capture® 2 High-Risk HPV DNA Test® (HC2) for primary cervical screening.

STUDY DESIGN: HPV FOCAL is a randomized trial comparing HC2 to liquid-based cytology (LBC) for screening women aged 25-65. AHPV and HC2 were compared at the baseline screen (n=3473). Genotyping was by the Aptima HPV 16 18/45 Genotype Assay. We assessed HPV genotyping and reflex LBC for colposcopy triage.

RESULTS: AHPV/HC2 agreement was 96.5% (kappa 0.76); positive agreement was 77.4%. The AHPV positive rate was 7.2% vs. 8.4% for HC2 (p=0.06). Based on HC2 screening, round 1 CIN2 and CIN3+ rates were 9.2/1000 and 5.2/1000 respectively. Using HC2 as the comparator test, AHPV CIN2+ and CIN3+ relative sensitivities were 0.96 and 1.00 (p=1.00) respectively. High-grade reflex LBC and HPV 16 infection were significantly associated with CIN3+. AHPV specificity was 0.94 vs. 0.93 (p=0.05) for HC2. Compared with triage of HC2+ with abnormal cytology or HPV persistence for 12 months, colposcopy referral would be significantly reduced (38.3/1000 vs. 60.8/1000; p<0.001) if AHPV+ women with abnormal LBC and HPV 16/18/45 were referred at baseline. CIN2+ and CIN3+ detection rates were not significantly different for the two strategies.

CONCLUSIONS: AHPV vs. HC2 screening had equivalent CIN2+ and CIN3+ detection. Triage of AHPV+ by abnormal reflex LBC and the presence of HPV 16/18/45 would result in a significantly lower colposcopy referral rate with similar CIN2+ and CIN3+ detection rates as the overall HC2+ referral algorithm.