p16/Ki67 dual stain triage versus cytology in primary human
papillomavirus-based cervical cancer screening with limited genotyping
Abstract
Background: The introduction of primary HPV cervical cancer
screening requires the implementation of an appropriate triage strategy
that will be effective in detecting high-grade cervical disease without
losing diagnostic specificity. Methods: From the 30.066
screening tests results, a total of 1086 with available high-risk human
papillomavirus (HRHPV) with limited genotyping, cytology and p16/Ki67
dual-stain were selected. Two triage strategies for primary HPV
screening were analyzed retrospectively based on the study group.
Performance characteristics for p16/Ki67 and cytology triage in
detection of cervical intraepithelial neoplasia grade 2 or worse (CIN2+)
and grade 3 or worse (CIN3+) were calculated, detected in colposcopic
biopsy. Results: In HPV16/18-positive cases, primary HPV with
p16/Ki67 triage was significantly more specific than cytology
(53.1%/16.8% for CIN2+; p<0.0001; 45.9%/17.0% for CIN3+;
p<0.0001), with yielded sensitivity (95.7%/84.8% for CIN2+;
p=0.0955; 100.0%/87.5% for CIN3+; p=0.0832). In other HRHPV-positive
cases (N16/N18), p16/Ki67 triage was also significantly higher specific
(51.3%/15.3% for CIN2+; p<0.0001; 44.5%/16.5% for CIN3+;
p<0.0001), with sensitivity (92.3%/74.4% for CIN2+;
p=0.0522; 90.9%/81.8% for CIN3+; p=0.5637). Diagnostic predictive
values were significantly higher for p16/Ki67 triage with the highest
PPV in HPV16/18-positive cases for CIN2+ (45.4%; 95% CI: 35.2-55.8;
p<0.0001) and very high NPV in all HPV-positive cases
regardless of detected genotype (96.3%-100.0%). The risk (1-NPV) for
CIN3+ in HRHPV16/18-positive/p16/Ki67-negative women was 0.0%.
Conclusions: Superior diagnostic performance compared to
cytology for detecting cervical cancer precursors indicates that
p16/Ki67 dual-immunostain may be a highly effective tool of triage in
primary HPV screening with limited HPV 16/18 genotyping in the secondary
cervical cancer prevention.