October 6 to 8, 2016, general practitioners and specialists head to the Entretiens de Bichat medical conference in Paris, France, to take stock of developments in the profession.

One subject on the agenda this year is endometriosis -- which occurs when tissue that normally grows inside the uterus grow outside it. Participants in a round-table event include Dr Pietro Santulli, gynecology surgeon at Cochin hospital in Paris and researcher at France's Inserm public research institution. While various treatments currently exist for the condition, Dr Santulli highlights the importance of weighing up all the benefits and risks before opting for surgery.

Endometriosis is often diagnosed late, sometimes after 10 years. Why is that so?

We can diagnose the most severe forms with MRI scans or pelvic ultrasounds, but endometriosis is a diverse condition with indistinct symptoms. Lesions can be found in the pelvic area (Fallopian tubes, uterus, ovaries), as well as in the urinary system (bladder, urethra), the digestive system (appendix, small intestine), the rectum, the diaphragm and the thorax. Certain women experience pain, others don't, some are fertile, others are not. There are sometimes superficial lesions, which can cause infertility and pain, but these play hide-and-seek. They are only visible by coloscopy and are difficult to treat. We often discover them when a patient is faced with unexplained infertility, in fact. One of the most common lesions is ovarian endometriosis, when cysts are present on the ovaries.

How could diagnosis be improved?

General practitioners and gynecologists should be made aware of signs of the condition, which usually appears in adolescence with period pain. The problem is that 70% of women have pains but they don't all have endometriosis. Patients should be questioned about associated signs, such as a mother or sister who has intense pain or endometriosis, a low BMI, the intensity of pain during her period, as well as pain outside of the menstrual cycle or bowel problems. Moreover, pain that resists treatment with classic anti-inflammatory drugs can be a warning sign.

What medical treatments are available to patients?

If classic anti-inflammatories don't work, we opt for long-term treatment with the contraceptive pill, taken continuously to stop menstruation, reducing inflammation and symptoms. Although this solution gives good results, it unfortunately doesn't help women who want to conceive a child. Studies are currently underway to develop other types of anti-inflammatory drugs.

In what case is surgery recommended? What are the benefits and risks involved?

Surgery can be used to remove lesions and relieve the pain of endometriosis, but the risk of recurrence is high for severe cases, at between 5% and 20%. We suspect that pieces of endometrium [Ed. the tissue lining the inner cavity of the uterus] can continue to move around in the region during menstruation, causing cysts to form on the ovaries or nodules to form in the intestine. Removing part of a young woman's intestine exposes her to between 10% and 15% risk of handicapping complications (abscess, fistula, problems with the urinary system, etc.). Sometimes, removing a cyst from an ovary can damage the ovary's function. Surgery is recommended to bring relief to patients in too much pain in spite of drug-based treatments. There needs to be a good team of multidisciplinary surgeons.

What can be done to help women suffering from endometriosis to conceive?

When a woman wants to have a child and that desire becomes her priority, assisted reproductive technology (in vitro fertilization) -- which has few complications -- can be envisaged. Lots of women with endometriosis can have children naturally. Studies show that despite having cysts on their ovaries, women have a 42% chance of conceiving, compared to 60-70% for the general population. We are currently carrying out research in the field of endometriosis of the uterus (adenomyosis) to develop specific treatments to help women have children via in vitro fertilization.