Cervical precancer thermal ablation versus LLETZ excision comparative efficacy study in WLWH (TALL Study): protocol for a randomised clinical trial in South Africa

Abstract

Background

Cervical cancer remains a significant global health concern and is the fourth most prevalent cancer among women. In South Africa, it is the leading cause of cancer-related deaths in women aged 15–44 years. The disease is typically preceded by persistent high-risk HPV infection, leading to cervical intraepithelial neoplasia and eventually cancer. Currently, in South Africa, management primarily involves excision, particularly through large loop excision of the transformation zone, which has associated risks and limitations. Thermal ablation is an alternative cost-effective treatment method, providing a straightforward approach to treatment, particularly advantageous in environments characterised by limited resources. The study aims to assess the efficacy, safety and patient experience of thermal ablation, providing valuable data for potential integration into South Africa’s cervical cancer prevention policies.

Methods

Randomised controlled trial in which 420 women living with HIV aged 30–60 years will be recruited from the Colposcopy Clinic at Tygerberg Hospital and will be followed up for a period of two years. The primary study endpoint is a test of cure that will be assessed by HPV genotyping, cervical cytology and histology at six month intervals. Other endpoints include the occurrence of adverse events.

Ethics and dissemination

The study protocol has been approved by the Health Research Ethics Committee of Stellenbosch University (Ethics Reference No: M20/11/035) and by the Western Cape Department of Health and Wellness via the National Health Research Database (WC_202109_016). All study procedures comply with the Declaration of Helsinki, South African Good Clinical Practice Guidelines and the Medical Research Council’s ethical guidelines. Trial results will be disseminated through peer-reviewed journals, national and international conference presentations and professional associations. A lay summary will be shared with the Community Advisory Board to guide community-level dissemination.

Trial registration number

Pan African Clinical Trial Registry: PACTR202504820339039.

STRENGTHS AND LIMITATIONS OF THIS STUDY.

• The use of a randomised clinical trial design minimises selection bias and strengthens the validity of comparative efficacy findings between thermal ablation and large loop excision of the transformation zone in women living with HIV.

• All participants will have histological outcomes assessed by an independent outcome assessor, ensuring objective and standardised evaluation of treatment efficacy.

• Structured follow-up protocols and participant retention strategies are in place to promote high data completeness and minimise loss to follow-up.

• Despite these efforts, participant attrition over the year follow-up period may affect the completeness of outcome data.

• The findings may be context-specific and may not be directly generalisable to other healthcare settings or populations without further validation.

Background and rationale

The burden of cervical cancer

Ranked as the fourth most frequently diagnosed cancer and fourth most common cause of death in women, cervical cancer resulted in approximately 661 021 diagnosed cases and 348 189 deaths in 2022 worldwide.¹ The Catalan Institute of Oncology/International Agency for Research on Cancer human papillomavirus (HPV) Information Centre estimates for 2023 indicate that in South Africa, 10 702 women are diagnosed with cervical cancer annually, while 5870 women die from the disease.² Cervical cancer remains the number one cause of cancer death in women in South Africa, particularly among women of reproductive age, 15–44 years.^{1 2}

HPV infection and pathological changes in the cervix

Cervical cancer is typically preceded by persistent oncogenic HPV infection, leading to cervical intraepithelial neoplasia (CIN) graded from CIN1 to CIN3 based on dysplasia severity.³ Most low-grade CIN, defined as CIN1, regresses within relatively short periods or does not progress to high-grade lesions. High-grade CIN, comprising CIN2 and CIN3 (also referred to as CIN2+), carries a much higher probability of progressing to invasive cervical cancer.4,7 The cervix, a cylindrical fibromuscular organ connecting the uterine cavity to the vagina, consists of the endocervix (columnar glandular epithelium) and ectocervix (stratified squamous epithelium), with the squamocolumnar junction being a common site for HPV-induced changes.⁸ Other sites of occurrence include the vaginal wall and vulvar epithelium.^{9 10}

HPV DNA prevalence in South Africa

Cervical HPV infection prevalence varies significantly across continents, countries, regions and population subgroups, with studies consistently showing the highest prevalence in sub-Saharan Africa and among women living with human immunodeficiency virus (WLWH).11,13 In South Africa, cervical cancer remains the leading cause of cancer death among women aged 15–44 years, with approximately 25% of these deaths occurring in WLWH.¹⁴ Recent estimates suggest that 3.2% of South African women in the general population are infected with HPV16/18 at any given time.^{14 15} Van Aardt et al conducted a retrospective study involving 1238 women, mean age of 40.94 years (SD 11.99), without cervical cytological abnormalities, revealing a high prevalence of high-risk HPV (hrHPV) infections at 44.92%.¹⁶ Similarly, Mbulawa et al found HPV infection rates of 36.7% (76/207; 95% CI: 30.4% to 43.4%) in HIV-negative women and a substantially higher prevalence of 74.0% (205/277; 95% CI: 68.5% to 78.8%) among WLWH (median age was 37 years (18–66 years) for HIV-negative women; 32 years (18–65 years) for WLWH).¹⁷ Denny et al in a demonstration study with 3062 women aged 30–65 years in South Africa, reported HPV positivity rates of 41.5% among WLWH and 17.4% among HIV-negative women.¹⁸ Furthermore, Dreyer et al documented a 41.2% (95% CI: 36.7% to 45.8%) prevalence of any hrHPV in WLWH compared with 19.6% (95% CI: 16.5% to 22.7%) in HIV-negative women in a South African screening trial involving 1104 women aged 25–65 years.¹⁹ These findings highlight the substantial burden of cervical HPV infection, particularly among South African WLWH, highlighting the urgent need for effective prevention and treatment strategies.

Management of cervical intraepithelial lesions

It is assumed that it takes an average of 10–20 years, in HIV negative women and 5–10 years in WLWH, before a persistent hrHPV infection may ultimately lead to invasive cervical carcinoma.^{5 6} Since malignant transformation has a long latency period, the detection and effective treatment of cervical precancer are crucial for preventing disease progression.²⁰

The approach to managing CIN is based primarily on the patient’s risk for progression to cancer and the availability of effective treatment strategies. Risk factors include age and grade of CIN. Women younger than 25 years have a lower risk of developing cervical cancer than those 25 years and older.^{13 21} CIN grade, CIN1 has a low potential for progression to malignancy and a high likelihood for regression, while CIN2/3 has a greater potential for progression and a lower potential for regression.^{22 23}

Management of CIN involves two main approaches. The first is observational management, which entails regular monitoring using HPV testing, cytology or colposcopy to observe the progression or regression of lesions, particularly for low-grade CIN1, which often regresses spontaneously. The second approach is treatment, which involves either excision or ablation of the cervical transformation zone (TZ). Treatment strategies can be categorised into two main methods: the screen-and-treat approach, where treatment decisions are based solely on a positive primary screening test; and the screen, triage and treat approach, where treatment decisions follow a positive primary screening test with a secondary ‘triage’ test, which may include histological confirmation.

Large loop excision of the transformation zone

In South Africa, the preferred treatment for premalignant cervical lesions is the large loop excision of the transformation zone (LLETZ), also known as loop electrosurgical excision procedure. This procedure is advantageous because it allows for histopathological diagnosis, providing critical information for further management. However, LLETZ requires electricity, sophisticated equipment and trained healthcare personnel, as well as access to histopathology laboratories, which can be challenging in resource-limited settings.

One of the risks associated with the LLETZ procedure is impaired pregnancy outcomes. There is a strong and consistent association between LLETZ and subsequent preterm birth, as summarised in meta‐analyses and observed in several countries.^{24 25} More recent research suggests that the increased risk is particularly associated with the depth of excision, with depths of 10–14 mm and especially >15 mm, posing higher risks. The lack of association in some studies is attributed to smaller excisions in the majority of treated women.²⁶

In addition to treatment-specific concerns, procedural complications such as cervical bleeding requiring suturing, bowel and bladder injury and infection have been documented in the literature.27,30 The necessity for electricity, local anaesthesia and resources to manage rare but serious adverse events like haemorrhage limits the use of LLETZ as a first-line treatment in low- and middle-income countries (LMICs).

Cryotherapy

Cryotherapy is an ablative treatment that destroys abnormal cervical tissue by freezing it with a cryoprobe. It is a relatively simple procedure that is considered cost-effective in many low-resource settings. However, its effectiveness is reduced for large or endocervical lesions. Gas-based cryotherapy, using either nitrous oxide or carbon dioxide, is the standard treatment for most precancerous lesions in LMICs. While the procedure itself is low maintenance, the cost and logistical challenges associated with acquiring, transporting and storing the gas can impact its overall cost-effectiveness. Additionally, the bulky gas tanks are not ideal for mobile health campaigns.

Thermal ablation

Thermal ablation (TA), also known as thermo-coagulation, involves the application of heat to destroy abnormal cervical tissue. In 2019, the WHO endorsed TA devices for treating precancerous cervical lesions eligible for ablation, releasing the ‘WHO Guidelines for the use of TA for cervical precancer lesions’. The WHO’s recommendation recognises that TA devices provide clinical outcomes comparable to cryotherapy and may help LMICs overcome supply chain and access challenges associated with cryotherapy. Moreover, TA offers additional advantages for LMICs, such as minimal electricity requirements for battery-driven devices and potential use of solar power in some models. Additionally, healthcare providers may find TA easier to administer due to its efficiency and simplicity. These attributes make TA a preferred choice in resource-constrained settings where access to advanced medical facilities may be limited.31,33

TA uptake has increased significantly over the last few years. In July 2019, the clinton health access initiative, funded by Unitaid, initiated a multi-country project aimed at enhancing access to cervical precancer screening and treatment. TA devices, along with comprehensive training and support, were rolled out in India, Kenya, Malawi, Nigeria, Rwanda, Senegal, Uganda, Zambia and Zimbabwe to expand access to precancer treatment. Additionally, TA has been introduced in Guatemala, the Philippines, Burkina Faso and the Ivory Coast.

The WHO guidelines for the use of TA for cervical precancer lesions recommend TA as the treatment of choice and LLETZ only when ineligible for ablative treatment for patients with histologically confirmed CIN2+, as well as for patients who screen positive for hrHPV or visual inspection with acetic acid (VIA) or hrHPV followed by VIA.³⁴ Consistent with the above-cited efficacy and feasibility considerations for TA, the WHO technical guidance and specifications of medical devices for screening and treatment of precancerous lesions in the prevention of cervical cancer reiterate that TA has documented efficacy and is recommended for low-resource settings.³⁵

In a meta‐analysis, Dolman et al reported an 87%–95% rate of CIN2+ cure by thermo-coagulation.³⁶ Similarly, in a meta-analysis including 23 studies and 6371 patients, six of which were analysed in LMIC, TA showed a treatment efficacy of 93.8% for CIN2+ lesions, as determined by biopsy. The study concluded that TA appears to be an effective treatment for CIN2+ lesions across a variety of settings, including LMICs, where its other commonly cited advantages include ease of use and simplicity.³⁷ A 2017 retrospective cohort study revealed that the cure rate for thermo-coagulation was 91.6%, and that for LLETZ was 97.1% at the 6 month follow-up, but the difference in cure rate between the LLETZ and cold coagulation was negligible at the 12 month follow-up.³⁸

Treatment failure in WLWH

Treatment failure (TF) or disease recurrence is particularly common in WLWH. Reimers et al reported TF in 55% of WLWH with CIN2+ and concluded that ‘clinicians treating CIN in WLWH should avoid raising expectations of cure and instead focus on the achievable goal of cancer prevention until there are better therapies for this patient population’.³⁹ Similarly, Debeaudrap et al reported a TF prevalence of 21.4% (95% CI: 15.8% to 27.0%) in WLWH, finding that TF was significantly greater in WLWH than in immunocompetent women (OR 2.7, 95% CI: 2.0 to 3.5).⁴⁰

However, a meta-analysis by Atemnkeng et al found that antiretroviral therapy (ART) was associated with a decreased risk of CIN2+ detection during follow-up, post-CIN management, particularly among ART users in high-income and upper-middle-income countries. They also reported a significantly lower risk of CIN2+ detection among WLWH who had undetectable HIV viral loads and those with higher nadir CD4+ cell counts.⁴¹

A point-of-care screen-and-treat demonstration study conducted by Denny et al reported a prevalence of CIN2+ at 12 months following treatment with TA of 23.2% in WLWH and 14.4% in HIV-negative women. The study did not include histological sampling prior to treatment, preventing an assessment of treatment efficacy using this marker. It also reported HPV type-specific clearance rates at 12 months, with 58.1% clearance in WLWH and 68.9% clearance in HIV-negative women following TA treatment.¹⁸

While numerous studies suggest comparable efficacy between excision and ablation, few have specifically analysed TA outcomes based on HIV status. One notable exception is a randomised, non-inferiority trial conducted by Basu et al in Zambia, which examined cervical precancer treatment responses considering baseline HIV status, HPV status and HPV genotype. Among HIV-negative women, the overall treatment success rate at a 12 month follow-up was 85.8% (783 of 913), with no significant difference between the treatment methods (cryotherapy: 83.9%, TA: 86.9%, LLETZ: 86.5%; p=0.5). Conversely, WLWH (n=1223) had a significantly lower overall treatment success rate of 62.1%, regardless of the treatment type (cryotherapy: 60.9%, TA: 62.7%, LLETZ: 62.7%), with no statistically significant difference observed among the treatment methods (p=0.83).⁴²

Additionally, a longitudinal cohort study conducted in Maharashtra, India, found that among HPV-positive women treated for CIN1 with TA, 11.8% progressed to a higher grade of abnormality. Complete regression of the disease, as confirmed by colposcopy and histopathology, was observed in 65.6% of HPV-positive WLWH who had high-grade CIN and were treated with TA.⁴³

A systematic review by Zhang et al on the efficacy, acceptability and safety of ablative versus excisional procedures in the treatment of histologically confirmed CIN2/3 included four studies, comprising three randomised controlled trials (RCTs) and one quasi-RCT. The review concluded that women with histologically confirmed CIN2/3 have a significantly higher risk of persistence or recurrence after ablative treatment compared with excisional procedures. This increased risk is consistent regardless of the women’s HIV status or the follow-up interval. The ablative methods used, however, were cryotherapy and laser vapourisation.⁴⁴

The WHO guidelines on screening and treatment of cervical precancerous lesions for cervical cancer prevention (second edition, Web Annexe A: syntheses of evidence) highlight the need for more research on TF risk in WLWH following TA.⁴⁵ While the study by Basu et al provides some evidence on this topic, the WHO notes that the overall evidence base remains limited. Consequently, the WHO recommends cryotherapy, TA or LLETZ for treating CIN grade 2 or 3, regardless of HIV status, but this recommendation is considered conditional and based on evidence of low to moderate quality.^{34 46 47}

Goal

Global health initiatives, such as the WHO Global Strategy for the Elimination of Cervical Cancer, aim to reduce the burden of cervical cancer worldwide through vaccination, screening and treatment. The overall goal of the proposed research is to provide critical data on the effectiveness of TA in WLWH to help reduce the burden of cervical cancer in this vulnerable population. The evidence generated by this study can inform policymaking and guide the allocation of resources to the most effective and sustainable interventions.

Study aims and objectives

The specific aims of this research are to compare the efficacy of TA versus LLETZ in preventing persistence and recurrence of precancerous cervical lesions in WLWH and to evaluate patient safety and treatment experiences.

Objective 1

To assess the TF of TA versus excision based on cervical cytology, histology and HPV status at 26 week intervals up to 2 years after treatment.

Objective 2

To describe type-specific HPV detection at 26 week intervals up to 2 years after treatment.

Objective 3

To assess patient experiences with side effects and safety when treated with TA versus excision.

Methods and design

Study design and overview

This study is a two-arm, parallel-group, open-label RCT designed to compare the efficacy and safety of TA versus LLETZ for the treatment of precancerous cervical lesions in WLWH.

A minimum of 420 evaluable participants, aged 30–60 years, who have screened positive for cervical disease (in accordance with South African guidelines: two Low-grade Squamous Intraepithelial Lesion (LSIL) results 6 months apart or one High-grade Squamous Intraepithelial Lesion (HSIL)) result will be enrolled.

Participants will be recruited from the Colposcopy Clinic at Tygerberg Hospital, Cape Town, South Africa and randomly assigned (1:1) to receive either TA or LLETZ. They will be followed for 24 months to evaluate primary and secondary outcomes. Study flow is illustrated in figure 1, and assessment procedures are detailed in table 1.

Figure 1. TALL study schematic. LLETZ, large loop excision of the transformation zone; TA, thermal ablation; VL, viral load; HPV, human papillomavirus; Cx, cervix.

Table 1. Study visit schedule and procedures.

Visit	Timepoint	Procedures
Screening and baseline	Day 0	Confirm eligibility criteria Informed consent (including optional specimen donation) Demographics and medical history Blood draw (HIV VL and CD4 count) Speculum exam+cervical samples (HPV testing, cytology, storage) Colposcopy to assess lesion eligibility Randomisation to TA or LLETZ If randomised to TA: cervical biopsies Perform assigned treatment (TA or LLETZ)
Eligibility criteria (Colposcopy)	—	Inclusion: Type 1 TZ with treatable lesion Type 2 TZ with full SCJ coverage by probe Exclusion: Suspicion of invasive/glandular disease Type 3 TZ or unreachable Type 2 SCJ Upper lesion limit not visible
Week 6 follow-up	Week 6±3 days	Telephone call with standardised questionnaire on procedure experience and side effects
Week 26 visit	Week 26±3 days	On-site self-sampling for HPV testing
Week 52 visit	Week 52±3 days	Blood draw (CD4 count) Speculum exam+cervical samples (HPV testing, cytology, storage and biopsy) Colposcopy
Interim treatment visit	Within 10 weeks of receiving Week 52 results	LLETZ treatment if any of the following: ASC-H or HSIL cytology ASCUS/LSIL cytology+any positive HPV NILM cytology+HPV16/18 positive CIN2+ histology
Week 78 visit	Week 78±3 days	On-site self-sampling for HPV testing
Week 104 visit	Week 104±3 days	Blood draw (CD4 count) Speculum exam+cervical samples (HPV testing, cytology, storage and biopsy) Colposcopy
Interim treatment visit	Within 10 weeks of receiving Week 104 results	LLETZ treatment if any of the following: ASC-H or HSIL cytology HPV16/18 positive CIN2+ histology

ASC-H, atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion; ASCUS, atypical squamous cells of undetermined significance; CIN, cervical intraepithelial neoplasia; HSIL, High-grade Squamous Intraepithelial Lesion; LLETZ, large loop excision of the transformation zone; LSIL, Low-grade Squamous Intraepithelial Lesion; NILM, negative for intraepithelial lesion or malignancy; SCJ, squamocolumnar junction; TA, thermal ablation; TZ, transformation zone.

Eligibility criteria

Inclusion criteria—Participants must meet all of the following criteria:

• Female gender.

• Living with HIV.

• Aged between 30 and 60 years.

• Negative pregnancy test.

• No prior treatment for cervical precancer or cancer.

• One of the following cytology results:

  • Two episodes of LSIL at least 6 months apart, or

  • One HSIL.

• On ART for at least 30 days prior to randomisation.

• Able and willing to provide written informed consent.

Exclusion criteria—Participants will be excluded if they meet any of the following criteria:

• Previous hysterectomy.

• Currently pregnant.

• HIV-negative.

• Age younger than 30 or older than 60 years.

• Hesitant or unwilling to undergo screening and treatment.

• Current or previous treatment for gynaecological cancer.

Participant recruitment and consent

The research team, comprising the principal investigator (PI), sub-investigator, medical doctor, field translator (for Afrikaans and isiXhosa or other local languages) and research assistant, will recruit volunteers from the Colposcopy Clinic. Ultimately, the PI is responsible for ensuring that informed consent is appropriately obtained and documented. The potential participant will be briefly introduced to the study and asked whether she will be interested in participating in the study. In the case where the potential participant indicated that she is interested in being enrolled in the study, a formal informed consent process will be done in a private area to ensure confidentiality. The person conducting the informed consent process must discuss all the information in the consent form. The informed consent discussion includes an explanation of all aspects of the informed consent form. The person obtaining informed consent will assess the potential participants’ understanding of the contents and process of providing informed consent. If needed, the understanding of the study will be verified by the individuals mentioned above and proper notes will be made in the source notes.

If the potential participant indicates interest in being enrolled, she will be asked to sign the informed consent form. Initials must not be allowed to serve as a signature. It should be explained to the potential participant that full names (as indicated on the birth certificate or South African Identity document), signatures and dates should be on the document as per International Council for Harmonisation (ICH) clinical guidelines and South African Good Clinical Practice (GCP) Guidelines.

If the potential participant declines to participate in the study, she must be reassured that this will not affect her clinical treatment. The person who provided informed consent will then provide his/her full name, sign and date the informed consent form only after ensuring that the potential participant understands the informed consent process and has signed the form. The time that consent was obtained must be captured on the document to verify that consent was obtained prior to performing any study-related procedures. Inform the potential study participant that they can withdraw at any time during the study and that the withdrawal will not affect their clinical treatment. Copies of consent forms will be made for each volunteer. The informed consent form is available as a online supplemental material file.

The goal is to recruit all study participants within 17 months. To meet this goal, 25 participants must be randomised each month. Investigators are expected to work with other departments within the institution, the Community Advisory Board (CAB) and outside referral centres to ensure that recruitment goals are met. A referral information form may be used to notify other clinics or departments within the institution of the study.

If recruitment is low at any time, the following strategies will be used:

1. Clinical investigator(s) reach out to other members of the department and other clinics to inform physicians and nurses about the study.

2. Clinical investigator(s) will engage the local CAB to help potential participants know about the study.

3. Clinical investigators will contact local clinical sites, including affiliates and Non-Govermental Organizations (NGOs), where pelvic exams and cervical cancer screenings are performed to request referrals.

Randomisation and allocation concealment

Randomisation is a process in which participants are assigned by chance (rather than by choice) to specific groups, typically for clinical research and clinical trials. The randomisation module in the Research Electronic Data Capture (REDCap) tool will be used to implement a defined randomisation model within the project. The randomisation list was generated by an independent statistician, and participants will be randomised in one of two arms at a 1:1 ratio. The randomisation process will be initiated by the site investigator or delegate, who accesses the web-based system after confirming the participants’ eligibility and informed consent. The participants’ unique study identifier and open-label study treatment allocation will then be automatically and electronically delivered to the local site investigator or delegate. Following randomisation, the research staff will inform the study doctor of the participants’ allocation group. Following randomisation, the participant will undergo treatment immediately.

Bias minimisation and blinding procedures

Due to the nature of the interventions, neither investigators or participants can be blinded to them. To reduce potential bias related to outcome measures, all outcome assessors, as far as possible, will be blinded to both the intervention and the care provided. Specimens will be reviewed by a pathologist with no knowledge of treatment assignment or case history. Both liquid-based cytology (LBC) and histology, which may involve subjective reporting, will be evaluated with this approach. HPV testing, being objective, will ensure reliable results. However, colposcopy will likely be performed by the same clinician administering the treatment, meaning the assessor for this measure will not be blinded. Additionally, telephonic interviews, which assess patients’ experiences and side effects, may involve subjective reporting.

Study procedures

Baseline and follow-up assessments

Blood draw

At the baseline visit, all participants will have blood drawn for viral load testing and CD4 cell count. Additional blood samples for CD4 cell count will be collected at weeks 52 and 104. Specifically, two 4 mL EDTA tubes will be collected for HIV viral load analysis and CD4 cell count.

Cervical cytology

Samples will be collected by trained healthcare workers during speculum examination with a cervical collecting brush. Cytology will be used as one of the measures of ‘test of cure’ after treatment of precancerous lesions.

BD Onclarity HPV assay

The BD Onclarity HPV assay is a qualitative in vitro test for the detection of HPV in cervical specimens using an endocervical brush/spatula combination or broom and placed in a BD SurePath vial. The test uses amplification of target DNA by polymerase chain reaction (PCR) and nucleic acid hybridisation for the detection of 14 hrHPV types in a single analysis. The test specifically identifies types 16, 18, 31, 45, 51 and 52 while reporting the other hrHPV types in groups (33/58, 35/39/68 and 56/59/66).

Colposcopy

Colposcopy aims to identify and diagnose potential cervical pathology, such as CIN and invasive cancer. Examinations will be conducted at the screening visit, as well as at weeks 52 and 104. Although digital colposcopic images will not be captured, the clinician will visually assess the cervix under low magnification before and after application of 5% acetic acid. Findings, including the location and extent of lesions and biopsy sites (where applicable), will be documented using annotated drawings in the participant’s source documents. This approach ensures consistency and clinical detail while maintaining a paper-based record of colposcopic findings.

Cervical biopsy

During colposcopy examination, a biopsy for histology will be taken at enrolment (for participants who are randomised into the TA treatment arm), at weeks 52 and 104. The biopsy will be taken using standard forceps (eg, Berger, Tischler or Kevorkian). A biopsy will be taken from the most abnormal area on colposcopy or from a normal area of the cervix if no abnormalities are identified. Post-treatment visit biopsies will be used as one of the measures of ‘test of cure’.

Self-collected samples for HPV testing

Cervicovaginal self-sampling will be performed at weeks 26 and 78. The device that will be used for self-sampling is the Evalyn brush. The Evalyn brush is approximately 20 cm in length and consists of a transparent case with wings. Within the casing is a pink stick with a pink plunger at one end and a white brush at the other. The depth of insertion is controlled by the wings. The brush will be inserted into the vagina and rotated five times. At each rotation, there is an audible click indicating the number of rotations. The device comes with an information leaflet detailing how the device is to be used.

Treatment procedures

Large loop excision of the transformation zone

A LLETZ is an excisional procedure of the cervical transformation zone that uses an electric current. The depth of the excision should be at least 5 mm. The procedure is performed with the patient in the lithotomy position using a wire loop electrode and an electrosurgical unit. Loops are available in a range of sizes and are insulated along the shaft to prevent injury to the patient and thermal damage to the vaginal mucosa.

An insulated speculum is inserted into the vagina to facilitate adequate visualisation of the ectocervix and transformation zone. The speculum is connected to suction during the procedure to evacuate smoke generated as the cervical tissue is excised.

A colposcopy will be performed to assess the cervix and lesion size. Local anaesthetics such as 1% lidocaine with 1:100 000 epinephrine will be used for LLETZ procedures. Excised tissue will be submitted for histology.

Thermal ablation

TA will be performed using the Liger thermal ablator as described in the WHO guidelines for the use of TA for cervical precancer lesions. The device is powered by a small removable 12-volt battery that is incorporated into the handle, which can be recharged over 2–3 hours and holds enough charge to complete at least 20 treatment procedures. Local anaesthetics such as 1% lidocaine with 1:100 000 epinephrine will be used. The thermal ablator probe will be heated to 100°C and applied over the TZ of the cervix for a period of 40 s. If the probe is not large enough to treat the entire transformation zone with one application, overlapping applications are allowed.

Safety and symptom evaluation

Wong-Baker pain rating scale

Immediately after the treatment procedure, women will be interviewed and asked to report the level of pain experienced during TA and LLETZ treatment using the Wong‐Baker FACES pain rating scale. This validated scale consists of an illustrated series of six faces with a range of emotions from happy (0) to crying (10) to indicate the level of pain. Scores are numbered from 0–10 in increments of two.

Six-week post-treatment telephone interview

Participants will be contacted six weeks after the procedure. A standardised questionnaire will be completed via telephone to assess the participants’ experience and possible side effects after the procedure.

Treatment-related adverse events or study-related injuries

In the unlikely event of an adverse event as a result of any study procedure, the participant will be referred to the on-site emergency gynaecology service at Tygerberg Hospital.

Optional procedures

Optional specimen donation

The participants will be informed (included in informed consent form) that to perform the research as discussed, the collection and storage of cervical specimens and health information from people with cervical abnormalities are needed. Following the completion of the clinical/laboratory tests outlined in this protocol, we propose to store residual specimens and/or health information. Globally, other investigators can ask whether these specimens can be used in future cervical cancer research. Participants will be assured that measures will be taken to protect their privacy, that is, their names will be replaced with a unique study number. The specimens will be stored at −80°C at the biorepository.

Retention, discontinuation and withdrawal

Retention strategies

• Scheduled phone calls or text reminders to maintain participant engagement.

• Providing travel reimbursements, small stipends or non-monetary incentives such as educational materials to encourage continued participation.

• Flexible scheduling whenever feasible.

• Identifying logistical, financial or personal challenges and providing necessary assistance, such as arranging transport.

Criteria for discontinuation or removal

• Request by the participant to withdraw.

• Request of the primary care provider if s/he thinks the study is no longer in the best interest of the participant.

• At the discretion of the health research ethics committee (HREC), investigator or other country-specific government agencies, as part of their duties to ensure that research participants are protected.

LTFU criteria

A participant will be considered lost to follow-up (LTFU) if she fails to attend a scheduled follow-up visit within the predefined ±3 week visit window and cannot be reached after at least three documented contact attempts (via telephone, text or other available contact methods) over a 30-day period following the missed visit. All reasonable efforts to re-establish contact will be made and documented in the source records prior to assigning LTFU status.

Early discontinuation evaluations

Participants who withdraw consent should be taken off the study without further evaluations. Otherwise, participants should undergo week 104 evaluations unless it has been <8 weeks since their last cervical biopsy. If withdrawing <8 weeks after the last cervical biopsy, then no further evaluations should be performed.

Missing data management

Multiple imputation (using the statistical programming language R; R Foundation for Statistical Computing, Austria) will be employed to adjust for bias. Multiple imputation techniques will be used to impute missing values for variables of interest. This involves creating multiple complete datasets, each with imputed values and combining results to provide unbiased and reliable estimates.

Study outcomes and endpoints

Primary and secondary endpoints

Primary study endpoint: treatment success is defined as the clearance of high-grade disease and hrHPV. Conversely, TF is defined as the persistence or recurrence of high-grade cervical lesions and/or hrHPV at any follow-up point after treatment, up to 24 months.

Secondary endpoints: participant safety and treatment experience, including the incidence and nature of adverse events reported at 6 weeks post-treatment.

Statistical considerations

Power and sample size

Sample size calculations were performed based on the proportions of participants treated successfully from the ‘Efficacy of point-of-care TA among high-risk human papillomavirus positive women in China’.⁴⁸

The sample size was computed using WinPepi.⁴⁹ The calculations are as follows: assumed proportion successfully treated in standard treatment LLETZ=87%, assumed proportion successfully treated in new treatment TA=85%, difference between proportions of 7% is defined as negligible, 1-sided test, significance level set at 5% and power 80%. Sample size required for non-inferiority of new treatment: n=189 in the new treatment arm and n=189 in the standard treatment arm (n=378). For the study to be considered a superiority study, the minimum important difference one would want to detect to consider one treatment superior to the other in terms of treatment success would be 10%; hence, for non-inferiority, a percentage lower than that would be needed for it to be defined as negligible. If we anticipate a percentage of 10% LTFU using the following formula, the adjusted sample size is: N (new)= N/(1% LTFU) = 378/(1–0.10) = 420 (210 in each treatment arm).

Data analysis plan

The baseline characteristics of the participants will be summarised by study arm and presented as proportions, means with SD or medians with IQRs. Fisher’s exact test, unpaired t-test or rank sum test will be used to compare characteristics in the two study arms.

Treatment efficacy: survival analyses will be performed to assess study outcomes. These analyses will be applied as this study is a comparative, longitudinal study on the efficacy of surgical treatments. Following treatment, efficacy outcomes will be measured every 26 weeks over a two year period. Measurements will be taken from the time of treatment until the time at which the event (the lesion) has cleared. Specifically, we will measure hazard ratios and present data in Kaplan-Meier curves with the associated survival tables. We will use log-rank tests to compare groups in a univariate analysis and Cox regression to test for multivariate analyses. The exposure variable will be the treatment arm and the outcome variable will be clearance as measured by cytology, histology and HPV test. Confounding variables will include age and HIV viral load and CD4 cell count. Event time ratio with 95% CI and p value <0.05 will be used to measure the strength of association and to declare statistically significant predictors, respectively.

Safety: adverse events/safety will be measured based on telephonic interview results at 6 weeks post-treatment. The analyses will concentrate on local (genital) adverse events, even though other adverse events will be recorded. We will describe the number of adverse events as the average number of events per group. Since we have two independent groups and we are reporting the average number of events, we will conduct independent t-tests. Analyses will be more exploratory since the study was powered to assess the primary study endpoint, that is, treatment efficacy and not safety per se. If we do, however, find differences that are significant (higher number of adverse events in one treatment group compared with the other), we will conduct further statistical investigation.

Monitoring and quality control

Data and safety monitoring plan

The PI will be responsible for all the data monitoring and for compliance with all the national and institutional REC policies and procedures for monitoring progress and safety, reporting unanticipated problems or adverse events and assuring actions resulting in suspension of the study are reported. All modifications to the protocol will be submitted for HREC approval. Summaries of all relevant discussions will be promptly disseminated to study personnel via email, and retraining procedures will be implemented as needed.

The treatment options that will be used during this trial have been approved by the South African Health Products Regulatory Authority and have been registered for the treatment of CIN, for which it will be used in this specific project. No investigational products are involved in this trial. The study will evaluate and compare established clinical practice options only. For this reason, no interim analyses will be performed; however, adverse events and serious adverse events will be closely monitored throughout the study.

Each participant will be assigned a unique study ID. Participant information will be stored on a password-protected computer and only those directly involved in the study will have access to it. The participant files will be stored in a locked cabinet.

Data management

Data will be captured into the REDCap database. Confidentiality will always be maintained. The data collected will be held on a password-protected computer and will only be accessible to those directly involved in the study.

All source documents will be checked for quality before the data is entered into the REDCap database. This involves ensuring data integrity and accuracy, handling errors/queries and missing data, checking all the information transcribed from another source, tracking data changes and corrections in accordance with GCP.

Throughout this process, the flagging system will be used. The flagging system is a source of communication between the study nurses, study coordinator, study doctors and the data capturers. The system involved the use of three different colours of stick-on flags, namely:

Orange indicates STOP: this flag is used to indicate that there is missing information on the source document for a specific participant.

Green indicates GO: this flag is used to indicate that the information is complete in the relevant source document and that the information is correct and ready to be checked and captured.

Yellow indicates PLEASE CORRECT: this flag is used to indicate that the file/source documents have gone through the quality control process and that there were some errors requiring correcting or that clarification is needed concerning a certain form before the information can be captured.

Ethics and dissemination

Ethical considerations

This study involves human participants and was approved by an Ethics Committee(s) or Institutional Board(s). The protocol of this study was submitted and approved by the HREC of Stellenbosch University (Ethics Reference No: M20/11/035). The protocol has also been submitted and approved by the Western Cape Department of Health, via the National Health Research Database (NHRD), to conduct research at Tygerberg Hospital (WC_202109_016).

All study procedures will comply with ethical guidelines and principles of the International Declaration of Helsinki, South African Guidelines for Good Clinical Practice and the Medical Research Council Ethical Guidelines for Research. Furthermore, all the participating researchers and investigators are familiarised with the ethical code of conduct and are certified in GCP.

The following cover has been arranged for clinical trials (insurance for research-related adverse events) in terms of the following two policies:

1. No fault Compensation Insurance policy number 73112119A017 underwritten by Lloyds for a limit of US$5 000 000 any one claim and in the aggregate.

2. Professional Liability Insurance policy number 4000/24901 underwritten by Stalker Hutchison Admiral for a limit of ZAR150 000 000. This policy has been extended to include Medical Malpractice.

Protocol amendments

Any significant protocol modifications, including changes to eligibility criteria, outcomes or analyses, will be communicated to all relevant parties through the following procedures:

• All investigators will be promptly informed of any protocol changes via formal communication channels. A revised version of the protocol, including detailed explanations of the modifications, will be distributed to ensure that all investigators are aware of the updates and can implement them accordingly.

• HREC/NHRD: protocol amendments that require ethical review will be submitted to the relevant REC for approval in accordance with institutional and regulatory guidelines. Modifications will be communicated to these bodies as soon as possible and approval will be sought before any changes are implemented.

• Participants will be notified of any changes that impact their eligibility, treatment or ongoing participation in the study. These changes will be communicated through written notifications, supplemented by verbal explanations during study visits to ensure participant understanding and consent to continue under the modified protocol.

• Modifications to the protocol will be updated in the South African National Clinical Trial Registry and the Pan African Clinical Trials Registry in accordance with regulatory requirements. This will ensure that the public and interested stakeholders have access to the most current information regarding the study’s design and objectives.

Dissemination plan

The trial results will be disseminated to the scientific community through presentations at relevant national and international conferences, dissemination through professional associations and via peer-reviewed journals. The results of this trial will also be used to develop and distribute educational materials to healthcare professionals to aid in interpreting and implementing the trial findings in clinical practice. A layman’s summary of trial results will be made available to CAB, which will assist in developing strategies to disseminate research findings back to the community in an accessible and meaningful way.

Patient and public involvement

Patients and members of the public were not involved in the design, recruitment or conduct of the study. However, the CAB will assist in disseminating results to the community in an accessible and meaningful way through lay summaries and feedback strategies.

Study timeline

Recruitment is expected to begin in July 2025 and will continue for approximately 17 months, concluding by November 2026. Each participant will be followed for a period of 24 months, and the final study visits are anticipated to be completed by November 2028.

Discussion

In this paper, we present the research protocol ‘Cervical Precancer TA versus LLETZ Excision Comparative Efficacy Study in WLWH (TALL Study)’. The assessment will focus on TF of TA versus excision in WLWH based on cervical cytology, histology and HPV status at 26-week intervals up to two years after treatment. Additionally, the study aims to document and compare patient experiences, side effects and safety between TA and excision.

Cervical cancer, a leading cause of female mortality, disproportionately affects South African women. Determining the effectiveness of TA, particularly in a population with a substantial HIV burden and hrHPV prevalence, provides valuable insights into its potential as a cost-effective and accessible treatment alternative. This research addresses the urgent need to enhance cervical cancer management by informing evidence-based decisions for cervical cancer screening and treatment guideline implementation. The study’s outcomes could significantly impact public health by introducing a more efficient and resource-friendly treatment option tailored to South Africa’s healthcare landscape.

The findings of this study have the potential to inform the incorporation of TA into the cervical cancer treatment framework in South Africa.