Endometriosis is a chronic condition that can affect girls of adolescent age and women up until menopause.
In this condition, endometrial tissue, which is normally present only inside the uterus, grows in other parts of the body — for instance, on the ovaries and fallopian tubes, on or inside the bladder, or on the kidneys.
Although there are no clear statistics indicating how many people live with endometriosis, this condition seems to be very widespread.
Estimates from the Office on Women’s Health suggest that more than 11% of biologically female people aged 15–44 in the United States may have this chronic condition.
Despite the numbers, research on endometriosis is still limited — currently, researchers do not know what causes this condition.
As for treatment, more often than not, doctors will advise people with endometriosis to have the extra endometrial tissue removed through regular surgical interventions, as the tissue tends to grow back.
The main reason why it is unclear how many people actually have endometriosis is that doctors often find the condition difficult to diagnose. Symptomatic diagnoses can lead to wrong conclusions, since doctors may mistake the symptoms of endometriosis for those of other conditions, such as pelvic inflammatory disease.
One way of spotting endometriosis-associated cysts is by performing an ultrasound, but this technique is not foolproof either.
The only way to diagnose the condition beyond a doubt is by conducting a laparoscopy — a minimally invasive surgery in which the surgeon introduces a laparoscope (a thin instrument with a micro light and a camera) that allows them to see inside the abdomen.
During this procedure, the physician can also collect tissue samples that they can send to a laboratory for analysis.
Working to eliminate inaccuracies
In a new study, researchers from institutions in Estonia and Finland — including the University of Tartu and the University of Helsinki, respectively — have aimed to find out how to make the diagnosis of endometriosis more precise.
“Today, the disease is mainly diagnosed surgically. In general, patients have to undergo a laparoscopic procedure in which lesions are surgically removed from the abdominal cavity. Small pieces of this tissue are taken for histological analysis that helps to confirm the diagnosis,” notes first study author Merli Saare, Ph.D.
In their study — the findings of which appear in the journal Biology of Reproduction — the researchers explain that studying gene expression in endometrial tissue is important in determining the correct biomarkers associated with endometriosis.
Moreover, identifying endometriosis-related biomarkers can help doctors better understand any changes in this chronic condition and their possible biological causes, which may allow them to address these changes more appropriately.
However, the team notes that gene expression in endometrial tissue is dependent on hormonal activity, which changes with a person’s menstrual cycle stages. If doctors collect sample tissue at the “wrong” phase of the cycle, this may render inaccurate or even false results.
Inching closer to finding ‘causal changes’
In the current study, the researchers analyzed endometrium samples from about 80 women. They compared each woman’s estimate about the phase of the menstrual cycle when a doctor had collected the tissue with the results from minute molecular analysis.
The researchers found that, more often than not, the information provided by the women was inaccurate, as the molecular profile established in the lab indicated different phases of the cycle.
“Our study helps to precisely determine the phase of the biopsy samples taken from the endometrium,” says Saare, adding that “This way, we can avoid examining the endometrium in different phases of the cycle,” which may be unhelpful.
While the current findings may not have yielded groundbreaking information, the study authors believe that, small as it may be, this step forward helps bring us closer to a better understanding of the causes and factors that shape the development of endometriosis.
“All small steps and discoveries take us closer. If our studies become more precise and we are able to eliminate side factors, it is much easier to find causal changes of the disease.”
Merli Saare, Ph.D.