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Treating cervical cancer with cryotherapy
10/6/15

The two vaccines currently available for cervical cancer don’t offer sufficient protection against this disease. Especially in developing countries where citizens can't cover the cost of these vaccines and where this type of cancer causes some 250,000 deaths a year. Cryotherapy, which consists of destroying cervical cells, could be a risk-free and affordable solution to fight cervical cancer more effectively.

Not so long ago, cervical cancer was a regular feature in the headlines. First of all, with the announcement of the launch of a vaccine against this disease.  Several months later, many articles appeared attacking or warning against the risks of serious secondary effects of these very vaccines. Since then, the ‘story’ of cervical cancer and its vaccines has been making far less noise, to the point where we might be led to think the problem has been solved and we can now cross this disease off the list of those that no long pose a threat to the population. And yet, this is not the case.
“We’re lucky to have these two vaccines on the market which offer a certain level of protection if they are given to young girls before their first sexual relations. But it’s not enough", explains Michaël Herfs, researcher at GIGA’s Pathological Anatomy and Cytology Unit at the University of Liège.

The vaccines available aren’t a universal panacea!

The vaccines aren’t a satisfactory solution for various reasons. First of all, these vaccines target the HPV 16 and HPV 18 viruses responsible for two-thirds of cases of cervical cancer. But there are approximately 15 HPV viruses that are likely to cause this disease. Therefore, the existing vaccines don’t cover a broad spectrum and only offer 50 to 60 % protection in vaccinated young women. “It’s not because a young woman is vaccinated that she won’t develop cervical cancer. Gynaecological monitoring and frequent screening of the disease are therefore still necessary”, Michaël Herfs explains. Another reason why these particular vaccines aren’t sufficient to fight cervical cancer is that they aren’t effective once the lesion has begun to develop. In other words, young women who haven’t yet had any sexual relations must be vaccinated. incidence of cancers papillomavirusThirdly, the final reason concerns the cost and logistics of the vaccination: three doses, which cost EUR 70 each, are necessary for the vaccine to have the expected effect. “While the cost issue doesn’t concern Belgium, where we benefit from a good social security system, it is very real in developing countries where cervical cancer is considerably more frequent than here”, Michaël Herfs points out. Indeed, while there are approximately 800 cases a year in Belgium (hence, we could prevent a maximum of 400 to 480 cases if we count on the maximum protection offered by these vaccines), this figure is considerably higher in Sub-Saharan Africa and the Caribbean. “In total, there are 500,000 cases of cervical cancer worldwide, 400,000 of which are in developing countries. All in all, there are 250,000 deaths per year. It’s the third deadliest cancer among women”, the researcher emphasises.

A population of cells more vulnerable to HPV

In 2012, Michaël Herfs and his colleagues discovered an as yet unknown population of cells in the cervix (Read the article "The origins of cervical cancer"). They also revealed that the vast majority (>90%) of cervical cancers develop from these cells. Following this discovery, the scientists obviously wanted to understand why this population of cells is more sensitive to HPV viruses and thus more likely to cause cancerous cells.  “There are a multitude of reasons to explain this. Above all, we showed that this population of cells is more easily infected by HPV than other populations of cells present in the cervix for ‘physical’ reasons of accessibility”, Michaël Herfs explains. “The cells composing it express more receptors to which the viruses can bind and, for instance, express less immune inhibitors”, the researcher specifies.

 

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