Accuracy of concurrent visual and cytology screening in detecting cervical cancer precursors in rural India

Abstract

The high burden of cervical cancer and inadequate/suboptimal cytology screening in developing countries led to the evaluation of visual screening tests, like visual inspection with acetic acid (VIA) and Lugol's iodine (VILI). We describe the performance of VIA, VILI and cytology, carried out in a multinational project called ''Screening Technologies to Advance Rapid Testing'' in 5,519 women aged 30-49 years, in detecting cervical intraepithelial neoplasia (CIN). VIA, VILI and cytology were positive in 16.9%, 15.6% and 6.1% women, respectively. We found 57 cases of CIN2, 55 of CIN3 and 12 of cervical cancer; 90% of CIN3 and 43% CIN2 cases were positive for p16 overexpression and high-risk HPV infection, indicating a high validity of histological diagnosis. The sensitivity of VIA, VILI and cytology to detect high-grade CIN were 64.5%, 64.5% and 67.7%, respectively; specificities were 84.2%, 85.5% and 95.4%. A high proportion of p16 positive CIN 3 (93.8%) and 2 (76.9%) were positive on cytology compared with visual tests (68.8% and 53.8%, respectively) indicating a higher sensitivity of cytology to detect p16 positive high-grade CIN. However, the immediate availability of the results from the visual tests permits diagnosis and/or treatment to be performed in the same sitting, which can potentially reduce loss to follow-up when women must be recalled following positive cytology. Organizing visual screening services in low-resource countries may facilitate the gradual building of an infrastructure committed to screening allowing the eventual introduction of more sensitive, highly objective, reproducible and affordable human papillomavirus screening tests in future.Early detection of high-grade cervical intraepithelial neoplasia (CIN 2-3 lesions) by screening and their effective treatment constitute the most common and widely used strategy to prevent cervical cancer throughout the world. Conventional cervical cytology is the most widely used screening test and the workhorse of large-scale cervical screening programs globally. Cytology is repeated frequently, at 1-5 year intervals, to ensure lesions missed in a given round of screening and incident lesions are detected in subsequent rounds. Collection of cervical cells, smear preparation, processing, reading and reporting requires several labor intensive steps as well as a laboratory infrastructure. Stringent quality assurance is vital to avoid any suboptimal performance of cytology in detecting cervical cancer precursors. The difficulties in ensuring optimal cytology screening with inadequate coverage for both testing and treatment of precursor lesions or lack of screening per se are responsible for the continuing high risk and burden of cervical cancer in developing countries.

Burden of cervical cancer and role of screening in India

“…A brief overview including strengths and weaknesses of each screening modality is presented in Table 5. [9101112131415] Salient findings of Indian studies[1617181920212223242526] on screening test performance are summarized in Table 6. The pooled sensitivity and specificity for VIA was found to be 67.65% and 84.32%, for VIAM, the pooled sensitivity and specificity were 65.36% and 85.76% and for VILI, the pooled sensitivity and specificity were 78.27% and 87.10%, respectively.…”

Evaluation of Stationary Colposcope and the Gynocular, by the Swede Score Systematic Colposcopic System in VIA Positive Women: A Crossover Randomized Trial

“…3,4 In addition, to be effective, cytologic screening needs to be repeated regularly. 5,6 Consequently, opportunistic unaided visual inspection of the cervix after applying 3% to 5% acetic acid (VIA) and examination under a 100-W lamp observing for color changes on the cervix by trained health personnel has been suggested as an alternative to cervical cytology screening in lowresource settings. 5,6 Visual inspection of the cervix with acetic acid is inexpensive, its results are immediately available, and the treatment can be administered on-site or by referral to a colposcopy clinic for biopsy and/or treatment.…”

Results of Cervical Cancer Screening in the Rural Population of Lucknow West, India, through a Camp Approach

“…High SIL incidence rates of 11 and 17% were also reported by Ambedkar et al [3] and Srivastava et al [4], respectively, in rural screenings. A moderate incidence of SIL ranging from 6.4 to 7.1% was reported in rural women by Das Gupta et al [5] and Deodhar et al [6, 7]. Verma et al [8] reported an SIL rate of 8.0% in a tertiary hospital in the rural area of Himanchal Pradesh, India.…”