· Patients who have undergone adequate surgery for endometriosis may relapse in 15% of cases, whereas 80% of relapse cases occur when surgery is partial
· Between 10% and 15% of the population has endometriosis, a percentage that rises to 40%-50% in women with sterility problems
· Women with endometriosis are at a slightly higher risk of developing ovarian cancer (1.3 points) and/or hormone-dependent tumors, such as endometrial cancer or of the uterus lining, and have a greater risk of developing melanoma and Hodgkin’s lymphoma
Despite affecting between 10%-15% of the population, endometriosis, which consists of the existence of mucosa from the endometrium outside the uterus cavity, is still a great unknown among the population, so much so that many women who suffer the condition are not aware of it. "In cases of deep endometriosis, the endometrium can invade the peritoneum of the pelvic area, become attached and produce fibrosis, inflammation and, therefore, pelvic pain," explains Dr. Javier de Santiago, head of the Gynecologic Oncology Service at MD Anderson Cancer Center Madrid – Hospiten, who indicates that it is usually in these cases of intense pain in which the woman finally consults a specialist. Another reason for diagnosis, he explains, is the inability of the woman to become pregnant. "Endometriosis is the cause of sterility in 40%-50% of women," says Dr. de Santiago.
Although the first approach to endometriosis is always medical, with the prescription of oral contraceptives, there may come a time when a surgical approach is necessary and, here, "the first surgery is essential", stresses Dr. de Santiago, who explains that, although 15% of patients relapse after adequate surgery, the percentage of relapse rises to 80% in patients who undergo partial and / or inadequate surgery. "It is very important that the first surgery be performed by a professional expert in endometriosis because, although the patient may be operated on by an expert at a later date, the results will no longer be the same", states the specialist, who always recommends asking for a second opinion in these cases.
As to why the condition occurs, Dr. de Santiago explains that the most widespread theory is that "menstrual blood, in addition to being expelled through the cervix is also expelled backwards through the fallopian tubes, which is known as retrograde menstruation, causing a build-up of tissue to occur in the ovaries, the peritoneum ... ", which means that endometriosis affects women of childbearing age. "If there is no period or hormonal stimulation, endometriosis atrophies and pain disappears," says the doctor. And hence the belief also, he continues, that endometriosis "is cured" with pregnancy. "Small areas of endometriosis build-up can atrophy in the 12-18 months in which a woman has no hormonal activity (pregnancy and breastfeeding), so the pain would be relieved, but nothing else, it is not curative," says Dr. de Santiago.
The association between endometriosis and cancer
There is no scientific evidence proving that endometriosis increases the risk of cancer, although an epidemiological association between endometriosis and ovarian cancer, some hormone-dependent tumors such as endometrial cancer, melanoma and non-Hodgkin's lymphoma can be observed. But, the specialist points out, "it's just an epidemiological association that implies a slight increase in risk, but it does not even allow us to say that endometriosis is a risk factor for this type of tumor."
In particular, continues Dr. de Santiago, "there are two types of ovarian cancer, clear cell and low grade serous, whose risk of development is 1.3 points more in patients with endometriosis, a figure that also implies a low risk". In addition, it is also possible to establish a relationship between endometriosis and the risk of ovarian cancer in those patients with a mutation in the ARID1A gene. "In patients with endometriosis who are also carriers of this mutation, we usually always remove the cysts, since they are more likely to develop ovarian cancer, but not so much because endometriosis is related to ovarian cancer but because ovarian cancer is related to this mutation", clarifies Dr. de Santiago.
In any case, it is important to stress here that the first treatment given to patients with endometriosis is contraceptive, since "research has shown that this therapy prevents the formation of cysts and endometriomata, in addition to reducing the risk of ovarian cancer”, says the specialist.
Likewise, patients with an early diagnosis of endometriosis, a long history of disease and a family history of ovarian cancer are monitored more closely and rigorously by ultrasound. Regular monitoring that means women with endometriosis who develop ovarian cancer will have a better prognosis. "Ovarian tumors are diagnosed late in 70%-75% of cases because it is a cancer of very rapid development, so these patients, under closer control, are also diagnosed earlier and, therefore, have a better prognosis”, says Dr. de Santiago.