EN / DA
Disease and treatment

Vulnerable population groups participate less often in screening for cervical cancer

When cervical cancer screening was introduced in Denmark in the 1960s, about 900 women were diagnosed with the disease each year. Since then, this number has declined to about 380. However, about one fourth of women are not screened in accordance with the current guidelines. In a new study, researchers have investigated the characteristics of the women who do not participate in screening. Low educational level and low income are two factors; mental illness and obesity are others. The researchers believe that more focused interventions are required to increase screening participation in specific population groups.

Some women actively choose to unsubscribe from screening, while others merely passively fail to participate. In Denmark, cervical cancer screening is offered to all women aged 23–64 years. The women who participate in screening have a considerably lower risk of developing cervical cancer, but about one in four women do not participate in screening in accordance with the recommendations of the Danish Health Authority.

“In this study, we used a nationwide Danish pathology registry to identify all women aged 23–49 years who were invited for cervical cancer screening in 2008–2009. We followed them in the registry for up to 4 years after the invitation to see whether they participated in screening. Using other nationwide Danish registries, we were able to examine sociodemographic and health-related characteristics of the large group of women who did not respond to the invitation. Our results showed, for example, that women originating from less developed countries, with a low educational level or with severe mental illness were much more likely to not participate in screening. We need to target these groups with better information and easier options for screening,” explains the first author, Elise Harder, PhD student, Unit of Virus, Lifestyle and Genes, Danish Cancer Society Research Center.

Greater risk of developing cancer

Most previous studies considered all women who were not screened as a homogeneous group, but this new study differentiated between women who actively chose not to participate by unsubscribing from the programme, and women who did not respond to the invitation at all. The researchers obtained the data from the Danish Pathology Databank, a national registry that contains data on all examinations carried out by pathology departments in Denmark, including cervical cancer screening.

“About 470,000 women 23–49 years old were invited for cervical cancer screening during 2008–2009. Of these, more than 10,000 women actively chose not to participate in screening, and a further 63,000 women did not respond to the invitation. The study does not identify why these women did not participate, but clearly women with a low educational level and low income were more likely to be non-participants. Thus, there is a large group that we do not manage to reach with our current screening offer.”

Studies have shown that cervical cancer screening has a strong preventive effect because it detects abnormal cells before they develop into cancer. The researchers therefore think that the sociodemographic inequalities in screening participation threaten one of the key principles of Denmark’s healthcare system: the principle of equal access to healthcare and equal treatment for all residents.

“In principle, everyone has equal access, but the study shows that, although 1 in 10 women with a high educational level did not participate, nearly 1 in 4 with a low educational level were not screened. This also applied to women who originated from less developed countries and women with severe mental illness, such as schizophrenia. These women were much less likely to be screened and thus had a greater risk of developing cancer and ultimately dying from it,” explains a co-author, Louise Thirstrup Thomsen, postdoctoral fellow, Unit of Virus, Lifestyle and Genes, Danish Cancer Society Research Center.

Vulnerable women can achieve equality

The new study does not directly explain why some women do not participate in cervical cancer screening. Nevertheless, previous research has provided some possible explanations.

“It is a combination of several factors. Some women may think that gynaecological examinations cross certain personal boundaries and are uncomfortable. Organizational factors are also important: for example, arranging a suitable appointment time may be difficult, as may giving priority to screening in a busy everyday life."

Although the researchers do not see any easy solutions, they hope that a new screening method, in which women can perform the screening at home, will solve some of the problem. The new method enables women to take a cervical sample at home using a soft brush and send it to a hospital, where it is tested for human papillomavirus, the virus that causes cervical cancer. This new screening option, which was implemented in the Capital Region of Denmark in 2017, avoids the inconvenience of making an appointment and the unpleasantness of a gynaecological examination. If the human papillomavirus test is positive, however, a follow-up examination is needed.

“A previous study in Denmark found that about half the women diagnosed with cervical cancer had not been screened regularly. We must therefore find new ways of reaching women and making screening as easy as possible for them.”

Factors associated with non-participation in cervical cancer screening – a nationwide study of nearly half a million women in Denmark” was published in Preventive Medicine. The Novo Nordisk Foundation awarded a main author, Susanne Krüger Kjær, Professor and Head of Research, Unit of Virus, Lifestyle and Genes, Danish Cancer Society Research Center, a grant in 2014 for the project Improving Survival of Ovarian Cancer. DNA from Routine Cervical Cytology Samples – the Value in Early Detection of Ovarian Cancer.

Elise Harder Christensen
PhD Student
Most of our studies are multidisciplinary and include collaboration with e.g. clinicians, molecular biologists, virologists, and biochemists. One of our focus areas is gynaecological cancers, and we work to prevent these diseases and to improve the survival rate. Through 2 population studies of 11,000 and 42,000 Danish women, respectively, collecting cervical cell samples, blood samples, and data on lifestyle habits, we have contributed to the identification of the strong link between cervical cancer and infection with human papilloma virus - HPV - a knowledge underlying the development of the vaccine against HPV, which presently may prevent 70% of all incidences of cervical cancer. The HPV vaccination is an important research area in the unit, aiming to prevent cervical cancer as well as other HPV related cancers, such as penile cancer, anal cancer, and certain types of head and neck cancer. Characteristically for our unit, we work with molecular biological markers tested on different biological samples, combined with data on life style factors.
Louise Thirstrup Thomsen
Postdoc
Epidemiologist with a background in public health, conducting registry-based and clinical research within the field of HPV-related diseases with a specific focus on screening for cervical cancer.
Susanne Krüger Kjær
Head of Unit
In the unit of Virus, Lifestyle and Genes one of our focus areas is gynaecological cancers, and we work to prevent these diseases and to improve the survival rate. Through 2 population studies of 11,000 and 42,000 Danish women, respectively, collecting cervical cell samples, blood samples, and data on lifestyle habits, we have contributed to the identification of the strong link between cervical cancer and infection with human papilloma virus - HPV - a knowledge underlying the development of the vaccine against HPV, which presently may prevent 70% of all incidences of cervical cancer.