Endometriosis affects about 10% of biologically assigned females. In this condition, the tissue similar to the lining of the uterus, also called endometrium, starts growing outside of the uterus. There are three common types of endometriosis defined based on where this tissue grows: ovarian endometriosis – when the tissue grows on the ovaries, superficial – when the tissue is found on the surface of the peritoneal cavity or organs, and deep infiltrating type – when the tissue is deep in the  the peritoneal cavity or organs.

Endometriosis is often associated with (1) pain: during period, sex, urination, defecation or on a daily basis (chronic pelvic pain), (2) infertility, and (3) endometriosis-associated ovarian cancers (EAOC).

Endometriosis itself shares many characteristics with cancer. First, similarly to cancer, endometriotic lesions can establish their own blood and nerve supply. Second, cells within these lesions can grow and multiply, while resisting the body’s natural immune and cell death mechanisms. Finally, we recently observed that endometriotic lesions can share several mutations with ovarian cancer.

Endometriosis and cancer – do not get alarmed yet!

As seen, endometriosis can share a few similarities with cancer and it is also a risk factor for developing two types of ovarian cancer. Endometriosis triples the risk of developing clear cell ovarian cancer and doubles the risk of developing endometrioid ovarian cancer. However, when we look on a global scale, people with endometriosis have 1.9% chance of developing ovarian cancer during their lifetime compared to 1.4% for people without this condition.

Usually only ovarian endometriosis might lead to EAOC. This topic is being actively investigated in our laboratories (Dr. Michael Anglesio’s and Dr. Paul Yong’s laboratories at the University of British Columbia) where we study specific mechanisms and mutations that might be responsible for endometriosis development and its malignant transformation. Right now, there are still more questions than answers about endometriosis and its associated ovarian cancers. However, we do know that most endometriosis patients with EAOC tend to have varying genetic patterns and to be diagnosed younger. Consequently, their EAOC rarely progresses beyond the low stage and is associated with favorable clinical outcomes.

Endometriosis – a difficult diagnosis

Given the clear connection between endometriosis and ovarian cancer, we need to increase endometriosis awareness of both medical personnel and the general public. Today, it takes on average 7 years to get a formal endometriosis diagnosis! For an undiagnosed endometriosis patient, this means 7 years of going from one doctor’s office to another, 7 years of unvalidated pain, 7 years of self-doubt, improper diagnosis, insufficient treatments, as well as 7 years of potential development of malignancy. 

The current gold standard to diagnose endometriosis involves a laparoscopy followed by a histopathological analysis; however, the experts have moved away from performing laparoscopies solely for diagnostic purposes. It is now performed when treatments, such as hormonal therapies, fail, and surgical excision of the lesion is expected to help with the symptoms. Current advances in visualization techniques and medical training have shown that endometriosis, especially ovarian endometriosis, can be diagnosed with ultrasound; transvaginal ultrasound demonstrated particularly high sensitivity (93%) and specificity (96%).

Awareness time!

While it is heartbreaking that people with chronic pain conditions have to advocate for themselves on top of everything they go through daily, it is important that one seeks the help and the level of expertise one requires. Endometriosis is a very common condition that might have several complications including ovarian cancer. If you or people in your life have been denied proper medical attention, please reach out to specialized centers to get the resources, diagnosis, and treatment you deserve.

The Endometriosis Network of Canada is a great resource to find a supportive community near you as well as specialized care. Moreover, EndoAct Canada is an organization dedicated to support people affected by endometriosis as well as to drive the policy change across the country. Finally, March is endometriosis awareness month, and it is a great time to learn more about endometriosis as well as to spread the word about everything you know!

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