A study in millions of patients confirms the relationship between endometriosis and ovarian cancer
Endometriosis can affect 10% of women of reproductive age. Various studies have pointed to the possibility that this pathology was related to a higher risk of developing ovarian cancer.. Now, this association is confirmed with a large study with real-life data, which has also served to show the different subtypes of ovarian cancer most associated with endometriosis.
The study, presented today, Friday, at the plenary session of the congress of the Spanish Society of Medical Oncology (SEOM), which is being held in Barcelona, was based on data from 128 million people, from 300 hospitals around the world, in mostly from Europe and the United States, although also from Asian, Australian and Brazilian centers.
“Although we started from a first database of 128 million patients, after making different selections we were left with 18 million, and finally we analyzed the characteristics of around one million women with and without endometriosis,” Ainhoa Madariaga details to this medium. , medical oncologist at the Gynecological and Breast Tumors Unit of the 12 de Octubre University Hospital in Madrid, and one of the authors of the work. “Having this large volume of data provides great robustness to our research.”
To carry out the research, a platform developed by the company TriNetX has been used that allows real-life data to be extracted in a structured way from the patients' medical history.. “It is possible thanks to the use of artificial intelligence that is used in various processes that allow, among other things, to balance data and handle a large volume; otherwise it would be impossible.. “It opens the door to conducting more research with real-life information,” adds the oncologist who presented the research at the national meeting.
“Endometriosis is not talked about, in many cases it is kept in a dark room”
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Greater risk of cancer, but without alarm
In 2019, a meta-analysis of different studies investigating the association between endometriosis and ovarian cancer had already been carried out and although its result was positive, the authors themselves warned that there was a high risk of bias.
“Therefore, the first question we asked ourselves was to see if this association was true; what we were able to verify is that women with endometriosis had up to 3.15 times the risk of suffering from ovarian cancer than those who did not suffer from it,” Madariaga points out. In any case, she emphasizes that this should not be a cause for alarm, since it is still a low risk and emphasizes that the vast majority of women with endometriosis will not have cancer.
“Even so, although the risk is low, it is also important to make this disease visible, which greatly affects the quality of life of women and is underdiagnosed. It may also be important to influence this population on healthy lifestyle habits that help prevent ovarian cancer or to have gynecological follow-ups for their condition,” comments the expert.. It should be noted that there is currently no ovarian cancer screening that has been shown to be effective.
Different types of ovarian cancer
Also in this study it was observed whether ovarian cancer in women with endometriosis had any specific characteristics. And so it was possible to verify, for example, that it is usually detected in earlier stages than in the general population, normally in stages I and II.
“We do not have data to explain it, but among the hypotheses we are working on is the fact that women with endometriosis tend to have more gynecological follow-ups, which can help diagnose cancer earlier.. But it is also possible that some treatments used for endometriosis, such as oral contraceptives, are a protective factor, or that the type of disease is different,” says Ainhoa Madariaga.
In fact, the study has also seen that ovarian cancer in women with endometriosis presents with a different biology. The most common are the clear cell and endometrioid subtypes, which tend to be rarer tumors in women without endometriosis.
“These differences had already been described, but thanks to this study we can confirm them and allow us to open lines of research on the rarest subtypes, about which we know more and more.”
Better prognosis
Another piece of information that is also extracted from the research is that the prognosis of women with ovarian cancer who have suffered endometriosis is better than that of those who have not suffered from it.
“At five years, the survival of women with endometriosis who have developed ovarian cancer is higher than those who have not had the disease.”. It may be due to the aforementioned different biology of this cancer, or also because it is usually diagnosed in earlier stages, when there are greater possibilities of cure,” says Madariaga.