Risk stratification and long‐term risk prediction of E6 oncoprotein in a prospective screening cohort in China

E6 oncoprotein is a necessary agent of HPV driven oncogenic transformation. This study is aimed at evaluating the risk stratification potency of HPV 16/18 E6 oncoprotein (E6) as a triage method for HPV positivity. Moreover, it also acts as a predictor of cervical intraepithelial neoplasia grade 3 or worse (CIN3+). The screening cohort of 1,997 women was followed for a 15 year period in approximate five‐year intervals. Participants were concurrently screened by HPV DNA testing (HC2), liquid based cytology (LBC), visual inspection with acetic acid (VIA) and were referred to colposcopy and biopsy if any tests reflected positive. E6 was performed on cervical samples collected from this cohort in 2005 and 2014. The ability of E6 to predict CIN3+ risk after the five‐ and ten‐year interval was evaluated. Among HPV positive women in 2005, E6 indicated the lowest positive rate (9.9%) compared to LBC (48.4%) and VIA (28.0%), however, a higher prevalence rate (10.3%) and 10‐year cumulative incidence rate (53.0%) of CIN3+ were detected among women who were E6 positive. Meanwhile, only 4.2% and 2.9% of women with abnormal LBC and positive VIA were diagnosed as prevalent CIN3+ in 2005, 23.0% and 16.5% developed to CIN3+ after year 10, respectively. Strong associations were found between precedent and subsequent HPV persistence and E6 oncoprotein expression (ORadjusted = 40.0 and 21.2, respectively). E6 oncoprotein could serve as a low‐cost, highly specific, strongly indicative point‐of‐care method in the triage and treatment of HPV positive women. What's new? DNA‐based testing for human papillomavirus (HPV) is poised to become the primary cervical cancer screening method in low‐ and middle‐income countries worldwide. However, while highly sensitive, HPV DNA tests lack specificity, creating demand for complementary tests to discriminate potentially cancerous infections from transient ones. This study examined the possibility of E6 oncoprotein detection to fill this role. In a cohort of 1,997 women, E6 positivity was associated with increased cumulative incidence rates of cervical precancer and with persistent HPV infection. E6 detection could serve as a fast, low‐cost risk stratification and long‐term risk prediction strategy in cervical cancer screening.