Swedish-born women more likely to develop ovarian cancer
[PRESS RELEASE, 2 October 2008] The risk of developing endometrial (uterine) and ovarian cancer for Swedish women depends on the country of their birth, according to a study from Karolinska Institutet. The risk is highest for Swedish-born women, and lower for women born in countries like Iran or Turkey.
The incidence of endometrial and ovarian cancer is relatively high in developed countries and relatively low in developing countries, the incidence in Sweden being one of the highest in the world. Scientists at Karolinska Institutet have now shown that these international differences can also be detected on comparing the original nationalities of Swedish residents.
The study was conducted using Karolinska Institutets national migration and health database, which includes over 5 million women, of which more than 700,000 are residents born overseas. The team analysed the incidence of cervical, endometrial and ovarian cancer between 1969 and 2004.
Their results show that women born in Sweden ran a higher risk of endometrial cancer and ovarian cancer than women born abroad, regardless of country. The risk was lower for women born in another country regardless of length of residency. The lowest risk of endometrial and ovarian cancer was observed in women from Iran and Turkey.
"We dont yet know why the risk of endometrial and ovarian cancer differs like this, but it might be due to lifestyle factors such as childbirth, use of the pill, and smoking habits," says associate professor Tahereh Moradi, who led the study.
The study also corroborates previous research into cervical cancer, which has shown that the chances of developing the diseases generally increase with age of initial residency in Sweden. The scientists link these differences in country-related incidence to the human papillom virus, the best known risk factor for cervical cancer.
"A lack of access to smear-test screening for certain groups in Sweden might be a significant factor behind the differences in risk of cervical cancer," says Dr Moradi. "The results support the idea that special screening should be targeted at women coming from high-risk countries at an older age."
Cervical, endometrial and ovarian cancers among immigrants in Sweden: Importance of age at migration and duration of residence
European Journal of Cancer, online 2 October 2008, doi: 10.1016/j.ejca.2008.08.017.