Screening Triage and Risk Stratification

Overview

* To investigate the performance of cytology, extended genotyping, p16/Ki67 dual stain cytology, DNA methylation and viral load as triage markers in post-menopausal HPV-screen-positive women aged 50-64 years in the organized screening program to predict the risk of developing CIN2+. (work package 1) * To investigate the performance of cytology, extended genotyping, p16/Ki67 dual stain cytology, DNA methylation and viral load six months after cervical excision to predict the long-term risk of residual/recurrent CIN2+ lesions among women aged 23-64 (work-package 2)

As HPV-positive women may have a transient infection which would be cleared with treatment, triage of HPV-positive women are needed to decrease the colposcopy referral. Liquid-based cytology (hereinafter cytology) are often used as triage for HPV-positive women. HPV 16/18 are the predominant HPV types in younger women and are for all aged referred directly for colposcopy. However as women age, hrHPV other types become more prevalent(10) and these types are triaged with cytology. However, as cytology undergo subjective interpretation and as it may have a decreased sensitivity in with increasing age(11, 12) cytology may not be the most optimal triage marker in postmenopausal women. p16/Ki67 dual stain cytology (hereinafter DS) is another triage marker. p16 is a cell-cycle regulator protein and Ki67 is a proliferation-associated protein which under normal circumstances are mutual exclusive. Thus, in an HPV-transformed cell co-expression of p16 and Ki67 indicates cell deregulation and increased risk of cervical precancer.(13) In several studies DS have shown better sensitivity and negative predictive value (NPV) as compared to cytology in triaging HPV-positive women(14-17) and women with low-grade cytology (ASC-US and LSIL)(18-20). Methylation of HPV-positive women benefits from a more objective evaluation than both cytology and DS and has in shown promising results in triaging HPV-positive women.(21) Most studies on DS and methylation have however, been conducted in younger women and studies evaluation the performance in postmenopausal women are needed. Women diagnosed with CIN2+ undergo excisional treatment removing the lesions and thereby reducing the woman's risk of developing cervical cancer. The most frequently used method is loop electrosurgical excision procedure (LEEP). Despite treatment, women previously diagnosed with CIN3+ lesion are at greater risk of developing cervical cancer with the risk increasing with increasing age.(22) Surveillance after LEEP consist of test-of cure (i.e. cytology and HPV test) six months after LEEP in several countries.(23-27) Treatment of CIN2+ is however, not always successful and residual or recurrent high-grade disease (CIN2+) occurs on average in 8% (ranging from 4% to 18%) of treated women, with the majority of treatment failure occurring mainly the first two post-operative years.(28, 29) Persistent HPV infection and positive margins after LEEP are risk factors for residual or recurrent disease after LEEP(28). However, not all women are at the same risk of recurrent disease, but still managed the same way as women at higher risk and therefore a future risk-stratification are needed to individualize the follow-up pathways. Moreover, introduction of a risk-stratification in the follow-up pathway may also decrease the number of open-ended follow-up pathways. In a recent study in HPV-positive women 60-64 years only 26% had follow-up as recommended.(30)