Co-Testing of Cervical Screening Tests in Detection of High Grade Cervical Intraepithelial Neoplasia
Dr. Satyanarayana Labani,
NICPR, Noida, Uttar Pradesh-201301, India.
Introduction: Co-testing performance for detection of high grade Cervical Intraepithelial Neoplasia (CIN) has not been adequately addressed from Low Resource Countries (LRCs). Where isolated tests do not have adequate performance, further explorations are recommended.
Aim: To evaluate the co-testing of conventional cervical screening tests such as Papanicolaou (Pap) and Visual Inspection Cervix with Acetic Acid (VIA), with care HPV on Cervical Samples (CHPV) or on Vaginal Samples (VHPV) in the detection of high grade CIN.
Materials and Methods: The cross-sectional study was conducted on ever married women of age 30 to 59 years in a rural community of Dadri. Women were screened by CHPV, VHPV, and Pap and VIA methods. Confirmation of screen positives was done by histology. Sensitivity, Specificity and likelihood ratios of different combinations of test determined to evaluate the performance.
Results: Total eligible women, 66.2% (5032/7604) responded for screening. Analysis was performed on 4658, after excluding those who did not complete all screenings. Co-testing of CHPV (OR=246) or VHPV (OR=278) with Pap had highest association. Positive likelihood ratios of CHPV and VHPV with Pap in CIN II+ detection rates were 13.0 and 11.8 and in CIN III+ the detection rates were 18.0 and 16.0 respectively. Higher sensitivities and specificities were observed in co-testing for CIN III+ detection as against CIN II+ lesions.
Conclusion: Choice of co-testing in a pair of tests for detection of high grade CIN is likely to depend on whether screening is targeted for developed or low resource country. VIA in isolation might not yield optimal results for LRCs.