Cervical cancer almost eradicated in Norway by the year 2039
Research findings
|Updated
Cervical cancer could be almost eradicated in Norway by the year 2039 thanks to an effective vaccine and the world's highest vaccination coverage, according to a new study.
Cervical cancer could be almost eradicated in Norway within the year 2039 thanks to an effective vaccine and the world's highest vaccination coverage, according to a study published in 2021.
Cervical cancer is a serious disease, with more than 300,000 women worldwide dying from the disease each year.
The human papillomavirus (HPV) virus is a common virus that can cause cancer in rare cases. Cervical cancer is caused by persistent HPV infection and can be prevented with HPV vaccination and cervical screening.
Less than four cases per year in 2039
A study published in 2021 shows that cervical cancer could be almost eradicated in Norway by 2039. In scientific terms, this is referred to as elimination, meaning there are fewer than four cases of cervical cancer per 100,000 women per year.
"Norway is on track to virtually eradicate cervical cancer by 2039," says Lill Trogstad, medical doctor and researcher at the Norwegian Institute of Public health.
Together with other researchers, she has calculated the time to elimination of cervical cancer in Norway with current vaccination and screening strategies. The results have been published in an article in the journal Preventive Medicine.
The study is a collaboration between researchers from Harvard University, the University of Oslo, the Norwegian Institute of Public Health, the Cancer Registry of Norway, and the Cancer Society in New South Wales, Australia.
- Allison Portnoy, Kine Pedersen, Lill Trogstad, Bo T. Hansen, Berit Feiring, Ida Laake, Megan A. Smith, Stephen Sy, Mari Nygård, Jane J. Kim, Emily A. Burger (2021) Impact and cost-effectiveness of strategies to accelerate cervical cancer elimination: A model-based analysis (sciencedirect.com)
Immunisation programme and transition to HPV testing yield results
“The study shows that the elimination of cervical cancer in Norway would not be possible without an HPV vaccination programme for girls,” says Trogstad.
The transition to HPV testing rather than cell samples in the cervical screening programme and vaccination of multiple cohorts of women are the key measures to accelerate the timeframe to eliminate cervical cancer in Norway.
“If vaccination of only girls in the 7th grade and cervical screening with cell samples had continued, the goal of elimination would not have been achieved until 2056,” explains Trogstad.
Changes in the HPV vaccination programme have accelerated the timeframe to elimination by 8 years. The shift in cervical screening from cell samples to HPV testing will further accelerate the timeframe by an additional 9 years. Suddenly, the goal becomes 17 years closer in time.
The table below summarises the various strategies implemented and their impact on accelerating the timeframe to elimination of cervical cancer in Norway.
|
HPV vaccination and cervical screening strategies in Norway |
Timeframe |
Number of years accelerated |
Estimated year of elimination |
|
Cervical screening with cell sample |
1992 - |
- |
Not achievable |
|
Vaccine for girls in 7th grade (from 2009) |
2009 - |
- |
2056 |
|
Catch-up vaccination for women up to 26 years (2016-2019) |
2016 - 2019 |
5 |
2051 |
|
Switching of vaccine from Gardasil to Cervarix (from 2017) |
2017 - |
2 |
2049 |
|
Vaccine for boys in 7th grade (from 2018) |
2018 - |
1 |
2048 |
|
Change in primary cervical screening from cell samples to HPV testing (from 2020) |
2020 - |
9 |
2039 |
|
Total effect |
|
17 |
2039 |
Norway has a high vaccination coverage
Norway tops the statistics on HPV vaccination with a vaccination coverage of 91 per cent. In comparison, Iceland has 85 per cent, Sweden 80 per cent, Denmark 62 per cent and Finland 60 per cent.
Currently, Norwegian girls and boys are vaccinated with Cervarix. There has been a debate whether they should instead receive the Gardasil 9 vaccine, which contains several more types of HPV than Cervarix. The potential impact of switching from Cervarix to Gardasil 9 has therefore been calculated.
“Switching to Gardasil 9 will not result in a faster elimination of cervical cancer in Norway than continuing with Cervarix. This may be because Cervarix provides overall good protection even against HPV types that are not included in the vaccine, known as cross-protection,” explains Trogstad.
Reference:
Allison Portnoy, Kine Pedersen, Lill Trogstad, Bo T. Hansen, Berit Feiring, Ida Laake, Megan A. Smith, Stephen Sy, Mari Nygård, Jane J. Kim, Emily A. Burger (2021) Impact and cost-effectiveness of strategies to accelerate cervical cancer elimination: A model-based analysis (sciencedirect.com)
(This news article was originally published in Norwegian in March 2021).
