Researchers find link between cervical cancer and nationality
A new finding by Karolinska Institutet in Sweden has shed light on the connection between cervical cancer and nationality. The study, which included gynaecological screening tests carried out for all women in the Nordic state over a 40-year period, showed that the threat of developing cervical cancer is greater for immigrant women living in Sweden. The results of the study were recently published in the International Journal of Cancer. Nationality is not the only risk factor, however. 'There are other risk factors too, such as smoking, sexual habits and not taking screening tests, which make it interesting to compare cervical cancer rates between different groups of immigrant women in Sweden and native Swedes,' explained Professor Pär Sparén, coordinator of the study. Based on the results of the study, which was carried out from 1968 to 2004, significant differences were found in women from other Nordic states and Central America. The researchers found that the differences are linked to the variation in the worldwide incidence of the Human Papilloma Virus (HPV), which is a key risk factor for cervical cancer. Past research has shown that the HPV link works by triggering changes in the cells of the cervix, which can cause cervical intraepithelial neoplasia to develop, thus resulting in cancer. To date, 250 types of HPV have been identified. Studies have found that 15 of these are classified as high-risk types; 3 as probable high-risk; and 12 as low-risk types. The 750,000-strong sample consisted of women from various countries that are registered on the Karolinska Institutet's national database of women's health. The researchers found 1,991 cases of cervical cancer in the group of immigrants. The figure signifies a 10% jump on the risk of developing cervical cancer. The finding also shows that the proportion of disease cases was lower for women who made Sweden their new home compared with women in their respective countries. When comparing the immigrant groups, the researchers also found that a wide variation exists. For example, women in east Africa were five times less likely to develop cervical cancer than women born in Sweden, the team said. But southern Asian women had a 50% less chance of developing the disease. Danish and Norwegian women were 80% and 70% respectively more likely to get the disease than Swedish women, while for women from Central America, the risk of developing the disease is 150% higher than for Swedish women. The work also showed that the risk of cervical cancer increased with the age of entry into Sweden. The risk dropped during the women's period of residency in their new homeland, the researchers said. 'The findings are significant for the more effective prevention of cervical cancer through for example, targeted screening programmes,' Professor Sparén commented. 'We need to introduce targeted screening for the prevention of cervical cancer amongst high-risk groups, particularly women over 50 during their first 10 years in Sweden.' Funding for the study was provided by the Swedish Council for Working Life and Social Research (FAS) and the National Health Care Sciences Postgraduate School at Karolinska Institutet. The study was a joint project with Mälardalen University in Sweden and Tehran University of Medical Sciences in Iran.
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