Lyon, France -- Doctors in Sweden have shown for the first time that although endometriosis is associated with an increased risk of various cancers, this risk does not depend on the number of times women with the condition have given birth.
Dr Anna-Sofia Melin, told the 23rd annual meeting of the European Society of Human Reproduction and Embryology today (Monday 2 July): Several epidemiological studies have shown an increased cancer risk among women with endometriosis, especially ovarian cancer. Infertility and never having given birth (nulliparity) are also known risk factors for different types of cancer, such as breast and endometrial cancer. However, as far as we know, this is the first study to investigate cancer risk among women with endometriosis that also stratifies for parity.
Dr Melin, a specialist doctor in the department of obstetrics and gynaecology at the Karolinska University Hospital in Stockholm, Sweden, and epidemiologists at the Karolinska Institute looked at data from 63,630 women who had been discharged from hospital with a diagnosis of endometriosis between 1969 and 2002. They were identified and followed up via the National Swedish Inpatient Register, the National Swedish Cancer Register and the Swedish Multi-Generation Register.
The researchers identified 3,822 cases of cancer amongst the women with endometriosis. While they found no overall increased risk of cancer, they did find that the women had an elevated risk of certain types of cancer, but that there was no significant difference in risk between women who had never given birth and those who had.
We found that, contrary to what one might expect, endometriosis and nulliparity did not combine to give a higher risk of cancer, said Dr Melin.
The researchers found that endometriosis increased the risk of developing ovarian cancer by more than a third (37%) above the risk for the normal population of women without endometriosis. There we
Contact: Emma Mason
European Society for Human Reproduction and Embryology