HPV E6/E7 mRNA Versus HPV DNA as Triage for Cervical Cancer Screening

AIM: To develop and standardize a cost effective methodology or algorithm for mRNA E6/E7 for HPV genotypes 16, 18, 31, 33 and 45 as compared to commercially available assays which can be incorporated to triage excess false positives from primary screening for cervical cancers.

Objectives:

1. Development and standardization of methodology /algorithm for mRNA E6/E7 testing for HPV genotypes 16, 18, 31, 33 and 45 using Real-time RT-PCR, in cervical samples.
2. To compare the test performance of this HPV E6/E7 mRNA assay to HPV DNA by HC 2 as secondary screening test, with the reference standard of colposcopy with biopsy, to triage women found positive in primary screening by VIA , in a population based screening for cancer of cervix.
3. To determine number of false positives in the primary screening test after testing VIA positives with a known high specificity secondary screening test (HPV-DNA HC II ) compared to HPV E6/E7 mRNA testing.

Study Population: Women in the age group of 30-65 years, who test positive on primary cervical screening test VIA will be enrolled for the proposed diagnostic tests along with reference standard of colposcopy with guided biopsy.

Study Site: Women tested positive on primary screening test VIA with referrals for further diagnostic testing at TMH will be enrolled under the study for proposed diagnostic tests along with reference test at tertiary care facility , Dept. of Preventive Oncology, Tata Memorial Hospital in Mumbai.

Sample Size To detect statistically significant difference in the test characteristics with 95% confidence limits, 80 % statistical power and alpha =0.05, we require to have around 180 cases of cervical intraepithelial neolplasia in the study.

With a demonstrated prevalence of around 2% for detecting high grade CIN lesions from our urban and rural community based cervical screening programmes, we need to enroll around 9,000 women from population based cervical cancer screening, to get 180 cases of cervical intraepithelial neolplasia

Methodology:

Women in the age group of 30-65 years undergoing routine cervical cancer screening through hospital ( Preventive Oncology screening clinic) and community based screening programs with abnormal test result using the primary cervical cancer screening test VIA will be recruited in the study. The primary screening test VIA will be administered by application of 5% Acetic Acid to the cervix and visualizing the cervix with the help of a halogen focus lamp. VIA will be considered to be positive if definite acetowhite lesions are visualized close to the squamocolumnar junction.

Criteria for a positive VIA test are presented below:

Positive VIA test:

1. Opaque, dense, dull, definite, well defined aceto white lesions, touching the squamocolumnar junction or close to the external os.
2. Strikingly dense acetowhite areas in the columnar epithelium.
3. Condyloma and Leukoplakia occurring closer to the squamocolumnar junction turning intensely white after application of acetic acid.
4. Growth on the cervix turning acetowhite.

The screened women who are tested Screen Positive by the primary screening test VIA will become eligible for recruitment in the study . Screen positive women from the outreach community screening programs will be referred to TMH ( Preventive Oncology screening clinic) for further diagnostic verification.

Participant Recruitment

The study participants will be recruited from Hospital ( Preventive Oncology screening clinic) and community based screening programmes in Mumbai. Medical Social Workers will explain the details and the purpose of the study to participants attending the screening clinic. Apparently healthy women in the age group of 30-65 yrs with an intact uterus and no past history of cervical neoplasia will become eligible to participate in the programme. If they are fulfilling the inclusion criteria given above, a written informed consent in the vernacular language (either Hindi or Marathi) will be obtained from the participant and a unique participant identification number will be assigned to the eligible women. Information on socio demographic and reproductive variables will then be collected using a detailed questionnaire.

Demographic, reproductive and sexual history data will be recorded at screening following informed consent..

Screen positive women will be tested for the presence of oncogenic HPV types by Hybrid Capture-II (HC-II) and HPV E6/E7 mRNA testing as diagnostic test. In addition to the above two tests all the screen positive women will also further receive Colposcopy with guided cervical biopsy, the reference gold standard test.

Colposcopy will be performed by trained doctors and the colposcopy impression will be noted down along with a punch biopsy from the aceto white area on the cervix detected by the primary screening test VIA. Biopsy specimens will be fixed in 10% formalin and will be processed and reported by the pathology laboratory at the Tata Memorial Centre.

The reference standard for final disease status will be histology.

Post Test Counseling :

At the end of all testing procedures post test counseling will be done by the Doctor and Medical Social Worker to explain the significance and the results of the testing procedures performed. The importance of follow up visit to understand the results of HPV/ mRNA E6/E7 and cervical biopsy will be explained to the women.

Follow up and Treatment:

Treatment for opportunistic and reproductive tract infections (RTI) will be provided. Women with High grade lesions (cervical precancers ) HSIL will be recommended to seek treatment with cryotherapy or LEEP (Loop Electrosurgical Excision Procedure) or by cold knife conization at the Tata Memorial Centre Mumbai.

Total Project Period: Three years:

Proposal submission, training, participant recruitment, data collection and analysis, including follow-up of cases at the end of enrollment period