Ovarian cancer risk for women with endometriosis

Researchers from the University of Queensland have carried out a large genetic study to better understand the biological overlap between endometriosis and ovarian cancer.
 
They combined datasets from multiple meta-analyses comparing the genomes of 15,000 people with endometriosis and 25,000 with ovarian cancer.
 
Using a technique called ‘Mendelian Randomisation’, they were able to find overlaps in risk factors between the two conditions and show a causal link between endometriosis and three epithelial ovarian cancer subtypes – clear cell, endometroid, and to a lesser extent, high-grade serous cell cancers.
 
Previous epidemiological studies had shown an association between endometriosis and ovarian cancer, but there was no way to predict which endometriosis patients were most likely to develop ovarian cancer later in life.
 
However, the new study was able to identify 19 locations across the genome that contain genetic markers that increase the carrier’s risk to both diseases.
 
‘Our research shows that individuals carrying certain genetic markers that predispose them to having endometriosis, also have a higher risk of certain epithelial ovarian cancer subtypes,’ lead investigator Dr Sally Mortlock said.
 
Endometriosis is estimated to affect around 12% of women of reproductive age.
 
The chronic condition is characterised by the presence of endometrial lesions outside the uterus, with the ovaries being a common site of disease.
 
Although benign, the authors write that endometriosis shares features with cancer, including metastatic-like behaviour, tissue invasion, proliferation, angiogenesis and decreased apoptosis.
 
Meanwhile, ovarian cancer remains the deadliest type of gynaecological cancer in women.
 
Fewer than 50% of patients survive beyond five years after diagnosis due to the absence of effective early detection strategies – which is why it has been dubbed by experts as a ‘silent killer’.
 
In some good news for patients, Dr Mortlock says that although the diseases are genetically linked, the risk of ovarian cancer for those with endometriosis is not substantially increased.
 
‘Overall, studies have estimated that 1 in 76 women are at risk of developing ovarian cancer in their lifetime,’ she said.
 
‘Having endometriosis increases this slightly to 1 in 55, so the overall risk is still very low.’
 
The latest research also opens up additional possibilities for future screening and targeted novel therapies according to GP Dr Angela Rassi.
 
She told newsGP the take home message for GPs and patients is that both endometriosis and ovarian cancer are serious conditions which need attention.
 
‘Endometriosis is an under-recognised condition with the potential for serious sequelae such as ovarian cancer, chronic pain and infertility, particularly if left untreated,’ Dr Rassi said.
 
‘We need to be taking women’s pain seriously and investigating appropriately to identify women with endometriosis, as this may open the door to potentially life-saving susceptibility testing for ovarian cancer.’
 
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endometriosis genetics ovarian cancer screening women's health