BD-ProExC as adjunct molecular marker for improved detection of CIN2+ after HPV primary screening

We investigated the efficacy of 8 cervical cancer screening strategies relative to cytology with emphasis on immunocytochemical detection of high-risk human papillomavirus (hrHPV)-induced cell transformation (BD-ProExC) as a tool of triage following primary cytology or hrHPV testing. 3,126 women were tested with BD-SurePath liquid-based cytology, hrHPV PCR genotyping and BD-ProExC immunostaining, and colposcopy verification to calculate sensitivity and positive predictive value (PPV) in detecting cervical intraepithelial neoplasia (CIN2(+)).

Compared to cytology screening, double testing with cytology and hrHPV resulted in the same sensitivity with a significant increase in the PPV (relative PPV: 1.83). However, twice as many tests were needed. Cytology with atypical squamous cells of undetermined significance (ASC-US) triage and hrHPV testing showed comparative results to double testing requiring only a small increase in number of tests. Screening for hrHPV subtypes 16/18, and ASC-US triage with hrHPV16/18 resulted in significant reductions in sensitivity (ratio: 0.74 and 0.96, respectively). Primary hrHPV/BD-ProExC screening was significantly more sensitive (ratio: 1.63/1.33), but had a significantly lower PPV (ratio: 0.64/0.88). ASC-US triage by BD-ProExC increased the PPV (ratio: 1.90) but decreased the sensitivity (ratio: 0.96). Primary hrHPV screening followed by BD-ProExC triage, led to significant increases in sensitivity (ratio: 1.30) and PPV (ratio: 2.89), and resulted in 55% fewer referrals for colposcopy.

From the investigated screening strategies, primary hrHPV DNA-based screening followed by BD-ProExC triage was determined to be the best screening strategy.

Immunocytological triage could be used to perfect hrHPV primary screening.