The CryoPop study: Screening for high-grade cervical dysplasia in Karnataka, India

To describe our experience of screening with visual inspection with acetic acid (VIA) and colposcopy to identify women with high-grade precancerous cervical lesions who were candidates for cryotherapy. Women were screened to determine eligibility for a clinical trial testing the safety and efficacy of a new, simple and inexpensive cryotherapy device (CryoPop®) targeted for use in low and middle-income countries (LMICs).

Prospective cohort study.

Primary and urban health centres in Belagavi, Hubballi and Vijayapur, India.

Women in the age-group 30-49 years, premenopausal, with no prior hysterectomy and no known HIV infection were eligible for screening.

Visual inspection with acetic acid was performed on eligible women following informed consent. VIA-positive women were referred for colposcopy and biopsy. Biopsies were read by two pathologists independently, with a third pathologist acting as tie-breaker if needed.

The primary outcome measures were the number/proportion of women screening positive by VIA and the number/proportion of those women screening VIA-positive found to have high-grade cervical lesions on biopsy (cervical intraepithelial neoplasia 2/3 [CIN 2/3]). Demographic variables were compared between women who screened VIA-positive and those who screened VIA-negative; a separate comparison of demographic and limited reproductive variables was performed between women who had CIN 2/3 on biopsy and those without CIN 2/3 on biopsy. Chi-square or Fisher's exact tests for categorical data and t-tests or analysis of variance for numeric data were used with all tests two-sided and performed at an alpha 0.05 level of statistical significance.

A total of 9130 women were screened with VIA between 4 July 2020 and 31 March 2021. The mean age of all women screened was 37 years (standard deviation = 5.6 years) with 6073 of the women (66.5%) in the 30-39 year range. Only 1% of women reported prior cervical cancer screening. A total of 501 women (5.5%) were VIA-positive; of these, 401 women underwent colposcopy. Of those who had colposcopy, 17 (4.2%) had high-grade lesions on biopsy, an additional 164 (40.9%) had low-grade cervical lesions on biopsy or endocervical curettage and one woman (0.2%) was found to have invasive cancer. VIA-positive women were younger and had higher levels of education and income; however, women who were VIA-positive and found to have CIN 2/3 were older, were more likely to be housewives and had higher household income than those without CIN 2/3.

Despite the COVID-19 pandemic, over 9100 women were screened with VIA for precancerous lesions. However, only 17 (4.2%) were found to have biopsy-proven high-grade cervical lesions, underscoring the subjective performance of VIA as a screening method. Given that this is significantly lower than rates reported in the literature, it is possible that the prevalence of high-grade lesions in this population was impacted by screening a younger and more rural population. This study demonstrates that screening is feasible in an organised fashion and can be scaled up rapidly. However, while inexpensive and allowing for same-day treatment, VIA may be too subjective and have insufficient accuracy clearly to identify lesions requiring treatment, particularly in low-prevalence and low-risk populations, calling into question its overall cost-effectiveness.