Evidence-Based Medicine: Pandora's Box of Medical and Surgical Treatment of Endometriosis

Biomarkers of endometriosis

Endometriosis represents a diverse disease characterized by three distinct phenotypes: superficial peritoneal lesions, ovarian endometriomas, and deep infiltrating endometriosis. The most widely accepted pathophysiological hypothesis for endometriosis is rooted in retrograde menstruation, a phenomenon observed in most patients. Endometriosis is closely linked to infertility, but having endometriosis does not necessarily imply infertility. The disease can impact fertility through various mechanisms affecting the pelvic cavity, ovaries, and the uterus itself. MicroRNAs (miRNAs) indeed represent a fascinating and essential component of the regulatory machinery within cells. Discovered in the early 1990s, miRNAs have since been identified as critical players in gene expression control. Unfortunately, ovarian endometrioma is a common gynecologic disorder for which specific serum markers are currently lacking. Some have examined urocortin for its ability to differentiate endometriomas from other benign ovarian cysts. Another potential marker, Cancer Antigen 125 (CA-125) is a well-established indicator for epithelial cell ovarian cancer and its levels can be elevated in conditions such as endometriosis. CA-125 is derived from coelomic epithelia, including the endometrium, fallopian tube, ovary, and peritoneum. In this review we examine the pathophysiologic basis for endometriosis and highlight potential markers to more fully characterize the underlying biochemical processes linked to this multifaceted disease state.

Hysterectomy Rate Following Endometrial Ablation in Ontario: A Cohort Analysis of 76,446 Patients

Background

Endometrial Ablation (EA) is an alternative to hysterectomy for the management of abnormal uterine bleeding (AUB); however, it does not eliminate the need for future surgical re-intervention.

Objectives

The primary objective of this study was to establish long-term clinical outcomes including the risk of hysterectomy in women who had undergone a primary EA.

Materials and Methods

This is a retrospective population-based cohort study utilising administrative data from the Canadian province of Ontario. This study assesses patients undergoing surgery in a publicly funded health care system.

Main outcome measures

We assessed women in Ontario undergoing a primary EA over a 15-year period. The primary outcome was hysterectomy within 5 years of primary EA. Secondary outcomes included myomectomy and repeat EA. All outcomes were also reported for 1, 3, 5, 10 and 15 years of follow-up. Logistic regression was used to establish predictors of hysterectomy within 5 years of primary EA.

Results

A total of 76,446 primary EAs were evaluated from 2002-2017, with 16,480 (21.56%) undergoing a subsequent surgical intervention. The average age of primary EA was 43.8 (+/- 6.3) years. Within 5 years, the evaluable cohort was 52,464, with 8,635 (16.46%) of women having proceeded to hysterectomy, 664 (1.27%) to myomectomy, and 2,468 (2.8%) to repeat ablation. By 15-years follow-up, the evaluable cohort was 1,788, with 28.75% had undergone a hysterectomy, 2.01% a myomectomy, and 5.20% a repeat EA. On logistic regression analysis, advancing age at time of EA was associated with significantly decreased odds of hysterectomy (OR=0.94, 95% CI 0.935-0.944, p<.0001) as was increasing surgical experience (OR=0.997, 95% CI 0.994-1.000, p=.022). Conversely, complex diagnosis (OR=1.102, 95% CI 1.042-1.164, p<.0001) and previous abdominal surgery (OR=1.288, 95% CI 1.222-1.357, p<0.0001) were associated with increased risk of subsequent hysterectomy.

Conclusion

Primary EA is associated with a high risk of progression to subsequent hysterectomy or other surgical intervention, without evidence of plateau of risk with long term follow-up.

What is new?

This study has the longest follow-up assessing hysterectomy outcomes in women undergoing a primary EA, with 28.75% of women having undergone a hysterectomy within 15 years of their EA.

The 10 "Cardinal Sins" in the Clinical Diagnosis and Treatment of Endometriosis: A Bayesian Approach

Evidence-based data for endometriosis management are limited. Experiments are excluded without adequate animal models. Data are limited to symptomatic women and occasional observations. Hormonal medical therapy cannot be blinded if recognised by the patient. Randomised controlled trials are not realistic for surgery, since endometriosis is a variable disease with low numbers. Each diagnosis and treatment is an experiment with an outcome, and experience is the means by which Bayesian updating, according to the past, takes place. If the experiences of many are similar, this holds more value than an opinion. The combined experience of a group of endometriosis surgeons was used to discuss problems in managing endometriosis. Considering endometriosis as several genetically/epigenetically different diseases is important for medical therapy. Imaging cannot exclude endometriosis, and diagnostic accuracy is limited for superficial lesions, deep lesions, and cystic corpora lutea. Surgery should not be avoided for emotional reasons. Shifting infertility treatment to IVF without considering fertility surgery is questionable. The concept of complete excision should be reconsidered. Surgeons should introduce quality control, and teaching should move to explain why this occurs. The perception of information has a personal bias. These are the major problems involved in managing endometriosis, as identified by the combined experience of the authors, who are endometriosis surgeons.

Surgical management of endometriosis-associated pain

Endometriosis and pelvic pain are associated. However, only half of the subtle and typical, and not all cystic and deep lesions are painful. The mechanism of the pain is explained by cyclical trauma and repair, an inflammatory reaction, activation of nociceptors up to 2.7 cm distance, painful adhesions and neural infiltration. The relationship between the severity of lesions and pain is variable. Diagnosis of the many causes requires laparoscopy and expertise. Imaging cannot exclude endometriosis. Surgical removal is the treatment of choice. Medical therapy without a diagnosis risks missing pathology and chronification of pain if not 100% effective. Indications and techniques of surgery are described as expert opinion since randomised controlled trials were not performed for ethical reasons, since not suited for multimorbidity while a control group is poorly accepted. Subtle endometriosis needs destruction since some cause pain or progress to more severe disease. Typical lesions need excision or vaporisation since depth can be misjudged by inspection. Painful cystic ovarian endometriosis needs adhesiolysis and either destruction of the lining or excision of the cyst wall, taking care to avoid ovarian damage. Cysts larger than 6cm need a 2 step technique or an ovariectomy. Excision of deep endometriosis is difficult and complication prone surgery involving bladder, ureter, and bowel surgery varying from excision and suturing, disc excision with a circular stapler and resection anastomosis. Completeness of excision, prevention of postoperative adhesions and recurrences of endometriosis, and the indication to explore large somatic nerves will be discussed.

Gene Expression Signature of Endometrial Samples from Women with and without Endometriosis

STUDY OBJECTIVE

To develop a prototype of a complex gene expression biomarker for the diagnosis of endometriosis on the basis of differences between the molecular signatures of the endometrium from women with and without endometriosis.

DESIGN

Prospective observational cohort study. Evidence obtained from a well-designed, controlled trial without randomization.

SETTING

Department of reproductive medicine and surgery, A.I. Evdokimov Moscow State University of Medicine and Dentistry.

PATIENTS

A total of 33 women (aged 32-38 years) were included in this study. Patients with and without endometriosis were divided into 2 separate groups. The group composed of patients with endometriosis included 19 living patients with endometriosis who underwent laparoscopic excision of endometriosis. The control group included 6 living patients who underwent laparoscopic excision of incompetent uterine scar after cesarean section, with both surgically and histologically confirmed absence of endometriosis and adenomyosis. An additional control/verification group included various previously RNA-sequencing-profiled tissue samples (endocervix, ovarian surface epithelium) of 8 randomly selected healthy female cadaveric donors aged 32 to 38 years. The exclusion criteria for all patients were hormone therapy and any intrauterine device use for more than 1 year preceding surgery, as well as absence of other diseases of the uterus, fallopian tubes, and ovaries.

INTERVENTIONS

Laparoscopic excision of endometriotic foci and hysteroscopy with endometrial sampling were performed. The cadaveric tissue samples included endocervix and ovarian surface epithelium. Endometrial sampling was obtained from the women in the control group. RNA sequencing was performed using Illumina HiSeq 3000 equipment (Illumina, Inc., San Diego, CA) for single-end sequencing. Unique bioinformatics algorithms were developed and validated using experimental and public gene expression datasets.

MEASUREMENTS AND MAIN RESULTS

We generated a characteristic signature of 5 genes downregulated in the endometrium and endometriotic tissue of the patients with endometriosis, selected after comparison with the endometrium of the women without endometriosis. This gene signature showed a capacity for nearly perfect separation of all 52 analyzed tissue samples of the patients with endometriosis (endometrial as well as endometriotic samples) from the 14 tissue samples of both living and cadaveric donors without endometriosis (area under the curve = 0.982, Matthews correlation coefficient = 0.832).

CONCLUSION

The gene signature of the endometrium identified in this study may potentially serve as a nonsurgical diagnostic method for endometriosis detection. Our data also suggest that the statistical method of 5-fold cross-validation of differential gene expression analysis can be used to generate robust gene signatures using real-world clinical data.

Pathogenesis Based Diagnosis and Treatment of Endometriosis

Understanding the pathophysiology of endometriosis is changing our diagnosis and treatment. Endometriosis lesions are clones of specific cells, with variable characteristics as aromatase activity and progesterone resistance. Therefore the GE theory postulates GE incidents to start endometriosis, which thus is different from implanted endometrium. The subsequent growth in the specific environment of the peritoneal cavity is associated with angiogenesis, inflammation, immunologic changes and bleeding in the lesions causing fibrosis. Fibrosis will stop the growth and lesions look burnt out. The pain caused by endometriosis lesions is variable: some lesions are not painful while other lesions cause neuroinflammation at distance up to 28 mm. Diagnosis of endometriosis is made by laparoscopy, following an experience guided clinical decision, based on history, symptoms, clinical exam and imaging. Biochemical markers are not useful. For deep endometriosis, imaging is important before surgery, notwithstanding rather poor predictive values when confidence limits, the prevalence of the disease and the absence of stratification of lesions by size, localization and depth of infiltration, are considered. Surgery of endometriosis is based on recognition and excision. Since the surrounding fibrosis belongs to the body with limited infiltration by endometriosis, a rim of fibrosis can be left without safety margins. For deep endometriosis, this results in a conservative excision eventually with discoid excision or short bowel resections. For cystic ovarian endometriosis superficial destruction, if complete, should be sufficient. Understanding pathophysiology is important for the discussion of early intervention during adolescence. Considering neuroinflammation at distance, the indication to explore large somatic nerves should be reconsidered. Also, medical therapy of endometriosis has to be reconsidered since the variability of lesions results in a variable response, some lesions not requiring estrogens for growth and some being progesterone resistant. If the onset of endometriosis is driven by oxidative stress from retrograde menstruation and the peritoneal microbiome, medical therapy could prevent new lesions and becomes indicated after surgery.