Thermal ablation offers new hope for cervical cancer prevention

November 11, 2019 by Gail Gustavson

Imagine you need treatment for cervical precancer.

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As part of PATH’s study on thermal ablation, clinic staff practice using a thermocoagulator device to treat cervical precancer. Tegucigalpa, Honduras. Photo credit: PATH/Rose Slavkovsky

You are a busy woman living in the metropolitan city of Tegucigalpa, Honduras. You have three young children, a full-time job, and you just received a call from your health care provider informing you that you need treatment for cervical precancer. The provider explains that, during your recent screening, they detected precancerous lesions on your cervix. Left untreated, the lesions could progress to cervical cancer. With some difficulty, you take a day off work, arrange for extra childcare, and catch a bus to the nearest health center—more than 45 minutes away. You arrive at the clinic, sign in, and wait. Over an hour later, the nurse informs you that they are not able to treat you today because the equipment is not working. She requests that you come back in one month. You return home untreated. And wait a month to repeat the journey again.

This story is all too common in low-resource settings. Far too often, women show up for treatment of cervical precancer and are turned away—either due to malfunctioning equipment, or a lack of the gas needed to perform cryotherapy. Sometimes these women are not able to come back for treatment until the lesion has progressed to cancer.

Why thermal ablation?

As we have written elsewhere, the standard of care for cervical precancer treatment in many low-resource settings is cryotherapy, a procedure that applies a cooled probe to the cervix to freeze precancerous cells. This method, however, has significant logistical drawbacks. For example, the large gas tanks required to cool the probe are costly and difficult to procure and transport.

To overcome these barriers to treatment, public health professionals are turning to an alternative method that has been used in the United Kingdom, North Ireland, and Scotland since the 1980’s: thermal ablation. This procedure uses a heated probe tip to the cervix in order to destroy the precancerous cells—a treatment that may sound painful, but generally causes minimal discomfort. The development of portable and low-cost thermal ablation devices in recent years—combined with the growing realization that cryotherapy isn't doing enough to prevent cervical cancer-related mortality—has led many low- and middle-income countries (LMICs) to consider thermal ablation for the first time.

Research shows that cure rates with thermal ablation are as good as or better than those achieved by conventional cryotherapy. Thermal ablation is also logistically feasible—treatment time is shorter than cryotherapy and the new devices are easy to transport, inexpensive, and battery-operated. In September 2019, the World Health Organization (WHO) published new guidelines recommending thermal ablation for treatment of cervical precancer.

While there is growing enthusiasm for thermal ablation, knowledge on patient acceptability in LMICs remains limited. To help inform decision-makers on this emerging technology, PATH carried out a study in Honduras in collaboration with local partners ASHONPLAFA and the Secretary of Health.

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This is an earlier prototype of the thermocoagulator used in the study. Photo credit: PATH/Patrick McKern

100% of study participants would recommend thermal ablation to a friend

Beginning in May 2018, the study team enrolled 319 women—all between the ages of 30 and 49—across four government health facilities in the metropolitan region of Tegucigalpa. Women were invited to participate if they received positive results from two screening tests— both HPV-DNA and visual inspection with acetic acid (VIA)—and had cervical lesions that were eligible for ablative treatment. Once consented and enrolled, each woman was treated. Each treatment cycle takes less than one minute. After treatment, women were asked about their experience with the procedure, including whether they experienced pain and whether they would recommend this procedure to a friend or relative. Women were also followed up with one month after the procedure to evaluate short-term safety outcomes.

As the recently published study results conclude, thermal ablation was well tolerated by study participants, and all women would recommend this procedure to a friend or relative. Furthermore, the procedure was found to be safe, with only mild side effects, none of which required medical care.

Study results on the level of cure of thermal ablation are forthcoming.

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Study staff in Tegucigalpa review data from the thermal ablation study. Photo credit: PATH/Francesca Holme

Another ally in the fight for elimination of cervical cancer

In 2018, the WHO Director General called for the global elimination of cervical cancer as a public health issue. Ambitious targets for achieving this goal include treatment of 90% of women with detected cervical precancer—a target now within reach thanks to new treatment alternatives such as thermal ablation.

While the vaccine to prevent HPV infection is an essential element in the elimination goal, another important and sometimes overlooked ingredient is affordable and feasible screening and treatment options—such as thermal ablation—for women who were not included in vaccine campaigns or could not afford the vaccine.

Based on the positive the thermal ablation study results showing that the method is safe and well-accepted among women, the Honduras Secretary of Health has incorporated thermal ablation in their national guidelines as an alternative to cryotherapy. With the regular use of thermal ablation at several health centers now underway, the Secretary of Health expects to see higher rates of treatment in the country. Providers, patients, and administrators are enthusiastic about the promise of thermal ablation and hope that it will ultimately enable the public health system to treat each woman in need, without delay. We hope that these results will inform decision-makers in other countries when investing in treatment options on their path to eliminate cervical cancer.