Development, Field Testing and Evaluation of the Efficacy of a Hand-held, Portable and Affordable Thermo-coagulator to Prevent Cervical Cancer in Low- and Middle-income Countries

A portable thermal ablation device for cervical cancer prevention in a screen-and-treat setting: a randomized, noninferiority trial

AbstractImplementing standard-of-care cryotherapy or electrosurgical excision to treat cervical precancers is challenging in resource-limited settings. An affordable technological alternative that is as effective as standard-of-care techniques would greatly improve access to treatment. This randomized controlled trial aims to demonstrate the noninferiority efficacy of a portable, battery-driven thermal ablation (TA) device compared to cryotherapy and electrosurgical excision (large loop excision of transformation zone (LLETZ)) to treat cervical precancer in a screen-and-treat program in Zambia. A total of 3,124 women positive on visual inspection with acetic acid and eligible for ablative therapy were randomized to one of the treatment arms. Human papillomavirus (HPV) testing was performed at baseline and at the follow-up. The primary outcome was treatment success, defined as either type-specific HPV clearance at the follow-up in participants positive for HPV at baseline, or a negative visual inspection with acetic acid test for those who had a negative HPV test at baseline. After a median follow-up of 12 months, treatment success rates were 74.0%, 71.1% and 71.4% for the TA, cryotherapy and LLETZ arms, respectively, thus demonstrating noninferiority (P = 0.83). TA was a safe and well-accepted procedure. Only 3.6% of those randomized to TA reported moderate-to-severe pain, compared to 6.5% and 1.9% for the cryotherapy and LLETZ arms, respectively. Thus, our randomized controlled trial demonstrates the safety and efficacy of TA, which is not inferior to cryotherapy or surgical excision.ClinicalTrials.gov registration: NCT02956239.

The use of thermal ablation in diverse cervical cancer “screen‐and‐treat” service platforms in Zambia

AbstractObjectiveThermal ablation (TA) was implemented in public sector cervical cancer prevention services in Zambia in 2012. Initially introduced as a treatment modality in primary healthcare clinics, it was later included in mobile outreach campaigns and clinical research trials. We report the feasibility, acceptability, safety, and provider uptake of TA in diverse clinical contexts.MethodsScreening services based on visual inspection with acetic acid were offered by trained nurses to non‐pregnant women aged 25–59 years. Women with a type 1 transformation zone (TZ) were treated with same‐visit TA. Those with a type 2 or 3 TZ, or suspicious for cancer, were managed with same‐visit electrosurgical excision or punch biopsy, respectively. A provider survey was conducted.ResultsBetween 2012 and 2020, 2123 women were treated with TA: primary healthcare clinics, n = 746; mobile outreach clinics, n = 1127; research clinics, n = 250. Of the 996 women treated in primary healthcare and research clinics, 359 (48%) were HIV positive. Mild cramping during treatment was the most common adverse effect. No treatment interruptions occurred. No major complications were reported in the early (6 weeks) follow‐up period. Providers expressed an overwhelming preference for TA over cryotherapy.ConclusionTA was feasible, safe, and acceptable in diverse clinical contexts. It was the preferred ablation method of providers when compared with cryotherapy.

Thermal ablation versus cryotherapy or loop excision to treat women positive for cervical precancer on visual inspection with acetic acid test: pilot phase of a randomised controlled trial

Cryotherapy is standard practice for treating patients with cervical precancer in see-and-treat programmes in low-income and middle-income countries (LMICs). Because of logistical difficulties with cryotherapy (eg, the necessity, costs, and supply chain difficulties of refrigerant gas; equipment failure; and treatment duration >10 min), a battery-operated thermal ablator that is lightweight and portable has been developed. We aimed to compare thermal ablation using the new device with cryotherapy. We report the pilot phase of a randomised controlled trial in routine screen-and-treat clinics providing cervical screening using visual inspection with acetic acid (VIA) in Lusaka, Zambia. We recruited non-pregnant women, aged 25 years or older, who were eligible for ablative therapy. We randomly assigned participants (1:1:1) to thermal ablation, cryotherapy, or large loop excision of the transformation zone (LLETZ), using computer-generated allocation. The randomisation was concealed but the nurses providing treatment and the participants were unmasked. Thermal ablation was achieved using the Liger thermal ablator (using 1-5 overlapping applications of the probe heated to 100°C, each application lasting for 40 s), cryotherapy was carried out using the double-freeze technique (freeze for 3 min, thaw for 5 min, and freeze again for 3 min), and LLETZ (using a large loop driven by an electro-surgical unit to excise the transformation zone) was done under local anaesthesia. The primary endpoint was treatment success, defined as either human papillomavirus (HPV) type-specific clearance among participants who were positive for the same HPV type at baseline, or a negative VIA test at 6-month follow-up, if the baseline HPV test was negative. Per protocol analyses were done. Enrolment for the full trial is ongoing. Here, we present findings from a prespecified pilot phase of the full trial. The final analysis of the full trial will assess non-inferiority of the groups for the primary efficacy endpoint. The study is registered with ClinicalTrials.gov, number NCT02956239. Between Aug 2, 2017, and Jan 15, 2019, 750 participants were randomly assigned (250 per group). 206 (84%) participants in the cryotherapy group, 197 (81%) in the thermal ablation group, and 204 (84%) in the LLETZ group attended the 6-month follow-up examination. Treatment success was reported in 120 (60%) of 200 participants in the cryotherapy group, 123 (64%) of 192 in the thermal ablation group, and 134 (67%) of 199 in the LLETZ group (p=0·31). Few participants complained of moderate to severe pain in any group immediately after the procedure (six [2%] of 250 in the cryotherapy group, four [2%] of 250 in the thermal ablation group, and five [2%] of 250 in the LLETZ group) and 2 weeks after the procedure (one [<1%] of 241 in the cryotherapy group, none of 242 in the thermal ablation group, and two [<1%] of 237 in the LLETZ group). None of the participants reported any complication requiring medical consultation or admission to hospital. Results from this pilot study preliminarily suggest that thermal ablation has similar treatment success to cryotherapy, without the practical disadvantages of providing cryotherapy in an LMIC. However, the study was not powered to establish the similarity between the techniques, and results from the ongoing randomised controlled trial are need to confirm these results. US National Institutes of Health.

Eric Lucas

Partha Basu