Role of molecular biomarker human papilloma virus (HPV) E6 oncoprotein in cervical cancer screening.

OBJECTIVE

The Onco E6™ Cervical Test, based on detection of the E6 oncoprotein of HPV 16 and 18 genotypes is evaluated as a screen for the early detection cervical neoplasia in resource-limited countries.

METHODS

This prospective study from June 2018 to June 2019 evaluated 235 women aged 21-65 years, who came to Gynaecological Oncology Outpatient Department by VIA, cytology, E6 oncoprotein test and by colposcopy. Screen-positive women by any of the tests or women with suspicious findings were further evaluated by biopsy at colposcopy. The McNemar test was used to compare the performance of E6 oncoprotein test with other screening tests.

RESULTS

The E6 oncoprotein positivity rate was 6.8% (n = 16) with 81.25% HPV 16 positive and 18.75% HPV 18 positive. Among VIA positive cases (n = 100), E6 oncoprotein was positive in 9% (p < .001). In histopathology confirmed chronic cervicitis, CIN I, CIN II, CIN III and invasive cervical cancer, E6 test was positive for 2.8%, 4.7%, 25%, 50% and 100% respectively. E6 oncoprotein test had the highest specificity and Positive Predictive Value (PPV; 97% and 75%) compared to VIA (42% and 18%), cytology (95% and 46%) and colposcopy (94% and 59%). Sensitivity of the E6 oncoprotein test for detection of CIN3+ was significantly higher than that of cytology (52% VS 25%) but lower than that of VIA (52% VS 74%).

CONCLUSIONS

The HPV E6 oncoprotein test is highly specific and is an effective triage test to reduce colposcopy referrals for the large number of false positive test outcomes seen with VIA.