New theory could mean the light at the end of the tunnel for people with endometriosis

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Around 1 in 9 Australian women will suffer from endometriosis at some point in their life. With Endometriosis, tissue similar to the lining of the uterus (the endometrium) grows in other parts of the body, often causing severe symptoms that puts life on hold during a woman’s period. Typically treatment focuses on pain management using medication or hormone therapy, and often laparoscopic surgery to remove scarring and adhesions on the reproductive organs, bladder, bowel and other affected organs. There is no currently cure. Now a new theory has been developed by researchers at Canada’s Simon Fraser University (SFU) that suggests a previously overlooked hormone, testosterone, has a critical role in the development of endometriosis. Their research could have direct impacts on diagnosis and treatment of the disease, signalling hope for women worldwide.

What is endometriosis?

The abnormal growth of endometrial tissue causes abnormal bleeding outside of the uterus, which can lead to the formation of adhesions and scar tissue on the reproductive and abdominal organs. These factors can cause severe pain, inflammation and irritation which can also damage fertility. While endometriosis most often affects the reproductive organs it is frequently found in the bowel and bladder and has been found in muscle, joints, the lungs and the brain. 

Endometriosis symptoms depend on where the endometrial tissue is located. Symptoms can include severe pelvic pain, painful periods, heavy or irregular bleeding, painful bowel movements and urination, nausea, and fatigue. Some women experience severe symptoms, while others may not have any symptoms at all. Pain levels aren’t a clear indicator of how extensive the endometriosis is; you could have mild endometriosis and severe pain, or extensive endometriosis and little to no pain.

In an Australian government report, endometriosis is estimated to cost Australian society $9.7 billion annually with two-thirds of these costs attributed to a loss in productivity with the remainder, approximately $2.5 billion being direct healthcare costs.

For many women endometriosis first develops during adolescence, and, as a progressive disease, can worsen until after menopause. For different reasons, many women will suffer for years before they reach a diagnosis and can access treatment. The variability of symptoms, and a societal “normalisation” of painful periods, may contribute to an average 7 to 12-year delay in women seeking help and diagnosis. 

Luci’s story

23 year old Luci is a full time university student, majoring in Chinese studies and marketing. Outside of study, Luci runs a clothing and accessories business, is a part-time model and social media influencer. Luci also has endometriosis.

Luci's experience with severe endometriosis has been both physical and mental: "I’ve developed this fear whenever I get my period. It really holds me back."

“I realised things weren’t normal for me back in high school when my menstrual cycle was very irregular and extremely painful,” Luci said.

“Usually, two days before my period starts I feel really tired and moody. My belly swells up and bloats as hard as a rock, and it would feel like someone was braiding my uterus. When my period starts I have lower back pain and during the first three days I am often bedridden. Standing up makes the pain worse. The best way I can describe the pain is as if my uterus is receiving an intense ‘Chinese burn’. It makes me feel very nauseous and sometimes I do end up throwing up. I have three days of non-stop hot-and-cold flushes - sometimes even a fever. My eyes swell up and I have body aches that feel like electricity is running through my body."

Two years ago Luci sought out medical help when she could no longer bear the pain and irregularity of her periods. “My traditional Chinese family had actually never heard of it before. When I would complain about the pain and how I felt really upset during my cycle I was told that all women go through this every month - just take some painkillers and I’ll be alright,” she said.

“It wasn’t until my condition worsened that I began to think it wasn’t normal. I described to my GP the symptoms I was having and had a pelvic exam. I am still building courage to have a laparoscopy, but I’ve seen several other health professionals - GPs, specialists, dieticians and Chinese herb specialists.”

While Luci’s experiences with health professionals have largely been supportive some have shown a lack of understanding of the severity of the disease. “Honestly, I don’t think I was always taken that seriously. There were a few that told me that I would grow out of it. They made it sound like I was just being dramatic and didn’t take my pain seriously. I was even told that all menstrual pain is the same for everyone and I just have a low tolerance for it,” she said.

“I was put on birth control pills to manage my cycle but my body didn’t react well so that wasn’t helpful at all. Painkillers helped me manage the pain to a degree but the fatigue is overwhelming and I still can’t function like normal. 

“For me the physical pain is bad but with uncontrollable mood swings I tend to be constantly frustrated with myself, and that ends up being reflected towards the people around me. I become super anxious and sensitive. It makes me feel like I’m an unstable person at times. So during the first few days of my cycle I am very antisocial. It's the type of thing that robs your joy of everyday happiness. A typical cycle for me involves a lot of tears, self-loathing, feeling very insecure and just very, very drained. I tell myself that this pain is temporary and it then becomes a mental battle trying to stay positive. I’ve developed this fear whenever I get my period. It really holds me back."

Endometriosis established as a developmental endocrine disorder

Endometriosis has been enigmatic since it was first described. The question of why some women get endometriosis, and others do not, has remained unclear. For sufferers like Luci this new theory about the role of testosterone holds the hope that one day far more effective treatments can be developed.

The new research is based on recent findings that women with endometriosis developed, as foetuses in their mother's wombs, under conditions of relatively low testosterone, compared to women without endometriosis.

According to the researchers' theory, this low testosterone "programs" the developing reproductive system of women to exhibit the unique suite of traits that is linked with endometriosis, including early menarche, short menstrual cycles, high pain sensitivity, high inflammation, and altered levels of the hormones that control ovulation and the menstrual cycle.

The researchers found their theory to be supported by a remarkable range of data in the literature, from genetics and development to endocrinology, morphology, life history, and evolutionary biology, thus providing the first comprehensive explanation for the traits associated with endometriosis.

The theory can explain almost all symptoms of endometriosis as downstream effects of low early-life testosterone. Their findings are presented in two recent papers published in Evolution, Medicine and Public Health, and Evolutionary Applications.

"Low testosterone in early development is the strongest known correlate of endometriosis, and its effects can explain the majority of endometriosis symptoms," said Simon Fraser University biological sciences professor Bernard Crespi, a Canada Research Chair and co-author of the work with graduate student Natalie Dinsdale. "What's more, the new theory has direct implications for endometriosis diagnosis and treatment."

Crespi notes that testosterone has apparently been overlooked in studies of endometriosis because it is usually regarded as a 'male' hormone, even though it is known to have key effects in females as well. It is very common for researchers to focus on oestrogen as a female hormone, and testosterone as a male hormone. In reality, these are both critically important hormones in all humans, and this research highlights the importance of studying the full range of steroids that can impact women's health.

"This work establishes endometriosis as a developmental endocrine disorder, with roots in early life," Crespi said. 

"It also clarifies the relationship of endometriosis with polycystic ovary syndrome, a disorder driven by too high, rather than too low, levels of prenatal testosterone. We show that polycystic ovary syndrome is essentially opposite to endometriosis in its causes, correlates, and major symptoms. As such, this work should help to transform our understanding of both disorders."

Still more patient support is needed

Luci hopes to see more awareness within the medical community and for more research to be done into this disease. “Ultimately I was really happy that I was able to find the cause of my pain,” Luci said.

“But I’m really afraid that endometriosis can lead to problems when trying to conceive. And I do wish there was a cure that doesn’t involve surgery or even removing my uterus.

“I really hope medical professionals are all educated about endometriosis, especially the mental aspects of dealing with this illness, because invisible illnesses are no less real or severe than the visible ones.”