Lower cost strategies for triage of human papillomavirus DNA-positive women.

Using human papillomavirus (HPV) testing for cervical cancer screening in lower-resource settings (LRS) will result in a significant number of screen-positive women. This analysis compares different triage strategies for detecting cervical precancer and cancer among HPV-positive women in LRS. This was a population-based study of women aged 25-65 years living in China (n = 7,541). Each woman provided a self-collected and two clinician-collected specimens. The self-collected and one clinician-collected specimen were tested by two HPV DNA tests-careHPV™ and Hybrid Capture 2; the other clinician-collected specimen was tested for HPV16/18/45 E6 protein. CareHPV™-positive specimens were tested for HPV16/18/45 DNA. HPV DNA-positive women underwent visual inspection with acetic acid (VIA) and then colposcopic evaluation with biopsies. The performance for detection of cervical intraepithelial neoplasia grade 3 or cancer (CIN3+) among HPV DNA-positive women was assessed for different triage strategies: HPV16/18/45 E6 or DNA detection, VIA, colposcopic impression, or higher signal strength (≥10 relative light units/positive control [rlu/pc]). The percent triage positive ranges were 14.8-17.4% for VIA, 17.8-20.9% for an abnormal colposcopic impression; 7.9-10.5% for HPV16/18/45 E6; 23.4-28.4% for HPV16/18/45 DNA; and 48.0-62.6% for higher signal strength (≥10 rlu/pc), depending on the HPV test/specimen combination. The positivity for all triage tests increased with severity of diagnosis. HPV16/18/45 DNA detection was approximately 70% sensitive and had positive predictive values (PPV) of approximately 25% for CIN3+. HPV16/18/45 E6 detection was approximately 50% sensitive with a PPV of nearly 50% for CIN3+. Different triage strategies for HPV DNA-positive women provide important tradeoffs in colposcopy or treatment referral percentages and sensitivity for prevalent CIN3+.

An evaluation of novel, lower-cost molecular screening tests for human papillomavirus in rural China.

New, lower-cost tests that target high-risk human papillomavirus (HR-HPV) have been developed for cervical cancer screening in lower-resource settings but large, population-based screening studies are lacking. Women ages 25 to 65 years and living in rural China (n = 7,543) self-collected a cervicovaginal specimen, had 2 cervical specimens collected by a clinician, and underwent visual inspection after acetic acid (VIA). The self- and one clinician-collected specimens underwent HR-HPV DNA testing by careHPV (QIAGEN) and Hybrid Capture 2 (HC2; QIAGEN) and the other clinician-collected specimen was tested for HPV16, 18, and 45 E6 using OncoE6 (Arbor Vita Corporation). Women who screened positive for any test and a random sample of those negative on all tests underwent colposcopic evaluation. The percent test positive was 1.8% for HPV E6 oncoprotein, between 14% and 18% for HR-HPV DNA testing, and 7.3% for VIA. The sensitivity for cervical intraepithelial neoplasia grade 3 or more severe (CIN3(+); n = 99) was 53.5% for OncoE6, 97.0% for both careHPV and HC2 testing of the clinician-collected specimen, 83.8% for careHPV testing and 90.9% for HC2 testing of the self-collected specimen, and 50.5% for VIA. OncoE6 had the greatest positive predictive value (PPV), at 40.8% for CIN3(+), compared with the other tests, which had a PPV of less than 10%. OncoE6 tested 70.3% positive for HPV16, 18, or 45-positive CIN3(+) and tested negative for all HPV16-, 18-, or 45-negative CIN3(+) (P < 0.0001). HPV E6 oncoprotein detection is useful for identifying women who have cervical precancer and cancer.

Cervical cancers require the continuous expression of the human papillomavirus type 16 E7 oncoprotein even in the presence of the viral E6 oncoprotein.

High-risk human papillomaviruses (HPV), such as HPV-16, are etiologic agents of a variety of anogenital and oral malignancies, including nearly all cases of cervical cancer. Cervical cancers arising in transgenic mice that express HPV-16 E7 in an inducible manner require the continuous expression of E7 for their maintenance. However, in HPV-associated cancers in vivo, E6 and E7 invariably are coexpressed. In this study, we investigated whether cervical cancers rely on the continuous expression of E7 in the context of constitutively expressed E6. We placed the inducible HPV-16 E7 transgene onto a background in which HPV-16 E6 was constitutively expressed. In transgenic mice with high-grade cervical dysplastic lesions and cervical cancer, repressing the expression of E7 led to the regression of all cancers and the vast majority of high-grade dysplastic lesions. In addition, cervical cancers were occasionally observed in transgenic mice in which E7 was repressed and then reexpressed. Our findings indicate that even in the presence of constitutively expressed E6, the continuous expression of E7 is required for the maintenance of cervical cancers and most precancerous lesions. These data have important implications for the potential clinical use of drugs designed to inhibit the expression and/or function of E7 to treat HPV-associated cancers.

Association of elevated E6 oncoprotein with grade of cervical neoplasia using PDZ interaction-mediated precipitation of E6.

OBJECTIVE: To determine the expression of human papillomavirus (HPV) type 16 E6 oncoprotein in cervical specimens of women with and without cervical intraepithelial neoplasia (CIN). MATERIALS AND METHODS: Cervical specimens from 2,530 unscreened women aged 30 to 54 years from Shanxi, China, were obtained. All women were assessed by liquid-based cytology, high-risk HPV DNA tests, and colposcopy with directed biopsy and endocervical curettage as necessary. Women with abnormal cytologic results or positive HPV DNA results were recalled for colposcopy, 4-quadrant cervical biopsies, and endocervical curettage. Women with biopsy-proven CIN and cancer and a convenience sample of HC2-positive, disease-negative women were tested for the presence of HPV-16 infection via HPV-16 E6 DNA-specific polymerase chain reaction. A PDZ interaction-mediated E6 oncoprotein precipitation method followed by E6-specific Western blot was performed on specimens from women with HPV-16 infections. Associations between elevated expression of E6 oncoprotein and CIN 2 and 3 were determined using logistic regression and a reference category of CIN 1 and disease-negative. RESULTS: A significant trend for the detection of HPV-16 E6 oncoprotein in specimen of women with proven HPV-16 infection was determined: 0% (0/12), 12.5% (1/8), 36.4% (4/11), and 42.9% (3/7) of those with negative findings, CIN 1, 2, and 3, respectively (p = .01). Compared with the category combining negative findings and CIN 1, detection of E6 oncoprotein was associated with CIN 2 (odds ratio = 10.9, p = .05) and CIN 3 (odds ratio = 14.3, p = .04). CONCLUSIONS: There is a significant association between elevated expression of E6 oncoprotein and grade of CIN. This finding seems consistent with the role played by E6 oncoprotein in carcinogenesis.

Feasibility study of a human papillomavirus E6 oncoprotein test for diagnosis of cervical precancer and cancer.

In a feasibility study using a prototype, lateral-flow test for human papillomavirus type 16, 18, and/or 45 (HPV16/18/45) E6 oncoproteins, 51 of 75 (68%; 95% confidence interval [95% CI] of 56 to 78%) of HPV16/18/45 DNA-positive specimens from women with a diagnosis of CIN3+ (cervical intraepithelial neoplasia grade 3+ or cervical cancer) tested positive for HPV16/18/45 E6 oncoprotein. None of 16 (95% CI of 0 to 37%) HPV16/18/45 DNA-positive cervical specimens from women with a negative or CIN1 diagnosis tested positive for HPV16/18/45 E6 oncoprotein.