Purpose Cytology-based screening has limited sensitivity to detect prevalent cervical precancers. HPV DNA testing is highly sensitive and provides a high, long-term reassurance of low risk of cervical cancer. However, the specificity of HPV DNA testing is limited, requiring additional, more disease-specific markers for efficient screening approaches. Experimental Design Liquid based cytology samples were collected from 625 women referred to colposcopy. A slide was stained using the CINtec plus cytology assay. Pap cytology and HPV genotyping were performed from the same vial. Clinical performance characteristics were calculated for all women, stratified by age, and for women referred with an LSIL Pap. Results p16/Ki-67-positivity increased with histological severity, from 26.8% in normal histology, 46.5% in CIN1, 82.8% in CIN2, to 92.8% in CIN3. Among women with CIN3, p16/Ki-67-positivity increased from 77.8% for women <30 years without HPV16 to 100% for women 30 years and older with HPV16. The sensitivity and specificity to detect CIN3+ were 93.2% and 46.1%, respectively, and increased to 97.2% and 60.0% among women 30 years and older. In women with HR-HPV-positive ASC-US and LSIL, sensitivity and specificity for detection of CIN3 were 90.6% and 48.6%, respectively. Conclusions p16/Ki-67 testing could reduce referral to colposcopy by almost half while detecting the most severe cases of CIN3. The high sensitivity of p16/Ki-67 with significantly improved specificity compared to HPV testing makes p16/Ki-67 a viable option for LSIL triage. Further studies are required to evaluate p16/Ki-67 as triage marker in HPV-based screening strategies.

Determining the causal attribution of human papillomavirus (HPV) genotypes to cervical disease is important to estimate the effect of HPV vaccination and to establish a type spectrum for HPV-based screening. We analyzed the prevalence of HPV infections and their attribution to cervical disease in a population of 1,670 women referred to colposcopy for abnormal cytology at the University of Oklahoma. HPV genotyping was performed from cytology specimens using the Linear Array assay that detects 37 HPV genotypes. We used different methods of type attribution to revised cervical disease categories. We found very high prevalence of multiple HPV infections with up to 14 genotypes detected in single specimens. In all disease categories except for cancers, there was a significant trend of having more infections at a younger age. We did not see type interactions in multiple genotype infections. HPV16 was the most frequent genotype at all disease categories. Based on different attribution strategies, the attribution of vaccine genotypes (6,11,16,18) ranged from 50.5 to 67.3% in cancers (n 5 107), from 25.6 to 74.8% in CIN3 (n 5 305), from 15.2 to 52.2% in CIN2 (n 5 427), and from 6.6 to 26.0% in