Imagine if, instead of 300 women being diagnosed in Ireland every year, no woman had to endure that heart-sinking conversation with their doctor about cervical cancer. Imagine if there were no deaths from cervical cancer – rather than the 90 woman who die from the disease every year.
This can be a reality within our lifetimes. We have the tools to make it happen: a national screening programme, treatment for cervical precancers and a national HPV vaccination programme open to boys and girls in early adolescence. It is vital that we make elimination a national ambition.
Most cervical cancers and anal cancers, and a third of head and neck cancers, are caused by human papillomaviruses (HPV). HPV is very common. About 80 per cent of sexually active women will have an HPV infection at some stage of their lives. Most women will clear the virus naturally. However, HPV can cause changes in the cells of the cervix. These precancerous abnormalities, if not identified and treated, can progress to cervical cancer over time. That is why cervical screening is so important. By attending screening appointments, women increase their chances of finding problems early, improving the prospects of effective treatment.
Screening
Cervical screening is one of three key elements of a World Health Organisation strategy for elimination of cervical cancer published late last year. It aims to ensure that 70 per cent of women are screened at least once by the age of 35, and again by the age of 45. The aim is to treat 90 per cent of those found to have precancerous cells.
These are global targets designed to raise standards across a diverse range of countries with a variety of health systems and access to technologies. In Ireland we can be more ambitious by using our expertise and infrastructure to move further more quickly.
CervicalCheck, the national cervical screening programme, began in 2008. Despite the negative impact of a failed attempt in 2018 to disclose the results of a retrospective audit to a large group of women who had, unfortunately, developed cervical cancer, some 1.24 million women have been screened. There have been 74,517 cases of high-grade cell changes, 66,432 cases of low-grade cell changes and 1,727 cancers detected.
This represents half of all cervical cancers detected in Ireland over this period. Every year we treat about 6,400 women for high-grade abnormalities. Many of these would develop cervical cancer if they were not identified by screening. This has brought about a measurable reduction in the incidence of cervical cancer in Ireland
In March 2020, CervicalCheck moved to HPV cervical screening. Rather than using cytology-based tests which rely on scientists observing changes in cells under a microscope, the programme now looks for the presence of HPV in a cervical screening sample using a PCR-based test. This checks for the presence of the virus and is less subjective than the previous method.
From the point of view of the women who are tested, the experience is the same. The sample is taken in the same way, but the results are more reliable. For every 1,000 women screened, we know that 20 are likely to have abnormalities. The smear tests used in the past pick up 15 of these. The HPV test, in contrast, will identify 18 of those abnormalities.
Ireland is among the first countries to move to this new way of screening based on HPV testing. While 80 per cent of eligible women participate in screening when invited, there are still pockets of the population where attendance is low, particularly among older women over 50 years of age. It is important that we try to understand why this is.
There is no doubt that the pandemic disrupted services and may have prompted some women to skip their appointment. It is crucial that we get back on track and address barriers to screening where they exist.
Vaccination
HPV vaccination is the other key element of a successful elimination strategy. At its height, HPV vaccine uptake reached 87 per cent in 2014-2015, making Ireland an exemplar country in Europe. A damaging anti-vaccine campaign saw this fall to about 50 per cent in 2016-2017. The Health Service Executive and the HPV Vaccine Alliance came together to restore trust in a safe and effective vaccine. This collective effort was supported by the singular impact of 26-year-old Laura Brennan’s high-profile campaign to raise awareness of the disease before it took her life in 2019. The value of Laura’s selfless advocacy cannot be overstated.
Today, vaccine uptake is still well below where it needs to be. A revitalised campaign to ensure girls and boys have their vaccine when offered – and to reach those who may have been missed during the pandemic – will be essential if Ireland is to drive down rates of disease in the years ahead.
Ireland’s screening and vaccination programmes have worked through challenges in recent years but provide a solid basis for tackling cancers caused by HPV. Advances in medical science and growing political momentum mean this generation could be the last in which sisters, wives, mothers and daughters are lost to cervical cancer.
Cara Martin is Assistant Professor in Molecular Pathology, Tumour Biology and Cancer Screening at TCD and co-founder, lead investigator and programme manager of Cerviva, the Irish cervical screening research consortium.