Early detection of cervical cancer through acetic acid application--an aided visual inspection

Abstract

Objective: To assess the sensitivity and specificity of visual inspection of cervix for detection of precancerous and early cancerous lesions of cervix.

Methods: In a Maternal and Child Health Care setting of New Delhi women underwent a detailed pelvic examination, visual inspection of cervix after 5% acetic acid application, cytology (pap smear), detailed colposcopic examination and colposcopic directed biopsy when indicated.

Results: Findings of aided visual inspection using 5% acetic acid and of cytology were evaluated among symptomatic 402 women against colposcopic findings and/or histologic reports. Seventy-three mild dysplasias, 50 moderate dysplasias, 45 severe dysplasias/Carcinoma in-situ and 40 early invasive cancerous cases were diagnosed histologically. The sensitivity of cytology (75.3%) was higher compared to that of acetic acid application (52.0%) for mild dysplasias. On the other hand, the sensitivity for detecting moderate dysplasias was 78% for cytology and 81.6% for acetic acid; for severe dysplasias/carcinoma in-situ it was 73.3% for cytology and 86.7% for acetic acid. For invasive cancers sensitivity for acetic acid application and cytology (95% for both modalities) was comparable. The specificity of cytology (99%) was higher compared to that of acetic acid application (94.3%). The false positive rate for cytology was 1.0% as against 5.7% for acetic acid application. The results of acetic acid application also showed a remarkable improvement in the sensitivity of unaided visual inspection for early cancerous lesion which was about 60% for early cancerous lesion and only 12% for mild dysplastic and 20% for moderate and severe dysplastic lesions in our earlier experience. It also reduced the false positive rates from 12% by unaided visual inspection to 5.7% by acetic acid application. Furthermore, cost of detection of one true lesion through acetic acid application (Rs.1689.00) was much lower as compared to the cost involved in cytology detected true lesions (Rs.2227.00). Visual inspection without acetic acid incurred Rs.6608.60 for detection of true lesion.

Conclusion: Screening for cervical precancerous and cancerous lesions using visual inspection aided by acetic acid may be a suitable low-cost and a feasible alternative modality for control of cervical cancer in a resource poor setting.