Visual Inspection with Acetic Acid (VIA) has been inducted in national cervical cancer screening programs of many countries as simple and inexpensive alternative to cytology. However, low specificity of VIA leads to unnecessary colposcopy or treatment that offsets the cost-savings. Detection of oncogenic Human Papillomavirus (HPV) is highly accurate and objective.
The large-scale community-based study from India aimed to evaluate the efficacy of HPV testing to triage the VIA-positive women so that specificity of VIA could be improved without compromising sensitivity.
VIA was used to screen 36,285 women between 30-60 years of age. All VIA-positive women had HPV-DNA test using Hybrid Capture 2 (HC-2) technology and colposcopy. Cervical punch biopsies were obtained if colposcopy was abnormal. Histology results or normal colposcopy were used as gold standard to evaluate test performances. Threshold for defining disease was CIN 3.
VIA was positive in 2625 women, of whom only 261 were HC-2 positive. Triaging of VIA-positive women with HC-2 resulted in significant reduction in referral rate from 7.2% to 0.7%. Triaging missed only 9 out of 65 cases of CIN3 and nil out of 41 cases of cancer originally detected by VIA. Positive predictive value (PPV) of sequential testing was 37.2%, against the PPV of only 4.0% for stand alone VIA. The Receiver Operating Characteristic curve showed 91.3% sensitivity and 93.5% specificity of HC-2 at RLU/PC cutoff of 1.0 when used sequentially with VIA. In a parallel study we observed high concordance between HC-2 test results from cervical samples collected before and immediately after VIA from same women. This suggests that samples for HC-2 can be collected immediately after VIA.
Triaging of VIA-positive women with HPV test can significantly reduce referral rate without significantly affecting sensitivity. This will substantially reduce programmatic costs by efficiently excluding the VIA false-positives.