Endometriosis is a common disease amongst women and is thought to occur in between 7 and 10% of the female population. And whilst it is known that the vast majority of these women will never go on to develop any form of cancer, the work that has been done recently in demonstrating a link between endometriosis and particular types of ovarian cancer could provide an easier way to provide the necessary screening for a disease which is notoriously difficult to diagnose.
A team of researchers from Ovarian Cancer Association Consortium (OCAC) have recently revisited a set of thirteen independent pieces of research into the link between endometriosis and ovarian and cancer and have now confirmed that women with self-reported history of endometriosis have significantly increased risk of developing clear cell carcinoma.
Clear cell carcinoma is a cancer in which malignant cells form in the tissue covering the ovary. About 6% of common epithelial tumours are known to be clear cell and of those 6%, 50% are known to be associated with endometriosis. The majority of patients with this type of cancer are between 40 and 80 years of age.
The researchers also showed that there was a clear link between endometriosis and what is called low-grade serous ovarian carcinomas which are slow growing cancers; they showed that endometriosis doubled the risk for women developing the disease. However, they also showed that there was no association between endometriosis and high-grade serous carcinomas which are much faster to develop and more aggressive, or other subtypes of ovarian cancer in the study.
In the UK women have a 2% chance of developing ovarian cancer during their lifetime, this translates roughly into one woman in every 50 developing the disease. Of these figures around nine out of every ten cases will be of the Epithelial Ovarian Cancer type and only 6% of these cases will be of the Clear Cell Carcinoma type (roughly half of one woman in every 50).