KRAS mutations and endometriosis burden of disease

Real world perspectives on endometriosis disease phenotyping through surgery, omics, health data, and artificial intelligence

Endometriosis is an enigmatic disease whose diagnosis and management are being transformed through innovative surgical, molecular, and computational technologies. Integrating single-cell and other omic disease data with clinical and surgical metadata can identify multiple disease subtypes with translation to novel diagnostics and therapeutics. Herein, we present real-world perspectives on endometriosis and the importance of multidisciplinary collaboration in informing molecular, epidemiologic, and cell-specific data in the clinical and surgical contexts.

Somatic PTEN and ARID1A loss and endometriosis disease burden: a longitudinal study

STUDY QUESTION

Is there an association between the somatic loss of PTEN (phosphatase and tensin homolog) and ARID1A (AT-rich interaction domain 1A) and endometriosis disease severity and worse clinical outcomes?

SUMMARY ANSWER

Somatic PTEN loss in endometriosis epithelium was associated with greater disease burden and subsequent surgical complexity.

WHAT IS KNOWN ALREADY

Somatic cancer-driver mutations including those involving the PTEN and ARID1A genes exist in endometriosis without cancer; however, their clinical impact remains unclear.

STUDY DESIGN, SIZE, DURATION

This prospective longitudinal study involved endometriosis tissue and clinical data from 126 participants who underwent surgery at a tertiary center for endometriosis (2013-2017), with a follow-up period of 5-9 years.

PARTICIPANTS/MATERIALS, SETTING, METHODS

PTEN and ARID1A loss was assessed using established immunohistochemistry (IHC) methods as proxies for somatic loss by two independent raters. PTEN and ARID1A status for each participant was defined as loss (loss in at least one sample for a participant) or retained (no loss in all samples for a participant). Primary analyses examined associations between PTEN and ARID1A loss and disease burden based on anatomic subtype (superficial peritoneal endometriosis (SUP), deep endometriosis (DE), ovarian endometrioma (OMA)) and rASRM stage (I-IV). Secondary analyses explored associations of PTEN and ARID1A loss with demographics, surgical difficulty, and pain scores (baseline and follow-up). Additionally, using previously published data on KRAS codon 12 mutations for this cohort, we investigated associations between variables in the primary and secondary analyses and acquiring two or more somatic events (PTEN loss, ARID1A loss, or KRAS mutation) in this cohort. The risk of reoperation over the 5-9 years was also examined.

MAIN RESULTS AND THE ROLE OF CHANCE

PTEN loss (68.3%; 86 participants) exceeded ARID1A loss (24.6%; 31 participants). Inter-rater reliability was substantial for PTEN (k = 0.69; 95% CI: 0.62-0.77) and ARID1A (k = 0.64; 95% CI: 0.51-0.77). PTEN loss was significantly associated with more severe anatomic subtypes (P < 0.001; participants with SUP only = 46.4%; participants with DE only or OMA only = 72.7%; participants with mixed subtypes = 85.1%), and higher stages (P = 0.024; Stage I = 47.8%; Stage II = 73.7%; Stage III = 80.8%; Stage IV = 81.0%). Results were similar for ARID1A loss, albeit with smaller sample size limiting power. PTEN loss was further associated with non-White ethnicities (P = 0.017) and greater surgical difficulty (more frequent need for ureterolysis) (P = 0.02). There were no differences in pain scores (baseline or follow-up) based on PTEN or ARID1A status. Reoperation was uncommon (13.5% of the cohort), and patterns in reoperation rates based on the presence of somatic alterations did not reach statistical significance.

LIMITATIONS, REASONS FOR CAUTION

Sequencing was not performed to determine the type of PTEN and ARID1A somatic mutations resulting in loss of expression.

WIDER IMPLICATIONS OF THE FINDINGS

These results demonstrate a link between PTEN somatic loss and greater endometriosis disease burden. These findings underscore the potential relevance of PTEN loss and other somatic driver mutations in a future molecular classification of endometriosis.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by Canadian Institutes of Health Research (CIHR) project grant (MOP-142273 and PJT-156084). P.J.Y. was supported by a Health Professional Investigator award from Michael Smith Health Research BC, Canada, and a Canada Research Chair (Tier 2) in Endometriosis and Pelvic Pain. M.S.A. was supported by a Michael Smith Health Research BC Scholar award, and CIHR project grants (369990, 462997, and 456767). The sponsors did not play any role in the study design; in the collection, analysis, and interpretation of data; in the writing of the report; and in the decision to submit the article for publication. C.A. declares receiving payment from Pfizer for a symposium; being on advisory boards for AbbVie and Pfizer; being President and past President of the Canadian Society for the Advancement of Gynecologic Excellence (CanSAGE), co-lead of EndoAct Canada, and a board member of IPPS. M.A.B. has received consulting fees from AbbVie and Pfizer and grants from Ferring outside the scope of this work. D.G.H. is the founder of Canxeia Health but has no current affiliation. M.K. has received consulting fees from Helix Biopharma outside the scope of this work. M.S.A. received reimbursement of travel and registration fees to attend and present at the 2023 and 2024 annual meetings for the Society for Reproductive Investigation (SRI). P.J.Y. declares receiving: payment for a lecture from the International Society for the Study of Women's Sexual Health (ISSWSH); honoraria from the CIHR; support to attend meetings from CanSAGE, ISSWSH, the International Pelvic Pain Society, the World Endometriosis Society (WES), the Society for the Study of Reproduction, and the Vulvodynia Summit; and discounted devices from Ohnut Wearable for a clinical trial. P.J.Y. is a data safety monitoring board member of a clinical trial funded by CIHR; and a strategic advisory board member for the Women's Health Research Institute. P.J.Y. served as a board of directors member for CanSAGE and ISSWSH; was a junior board of directors member for WES; is a current board of directors member for WES; and was a committee chair for the Society of Obstetricians and Gynaecologists of Canada. A subset of these results was presented by the first author at the 71st Society for Reproductive Investigation Annual Scientific Meeting on 15 March 2024. Other authors have nothing to declare.

TRIAL REGISTRATION NUMBER

N/A.

Understanding Deep Endometriosis: From Molecular to Neuropsychiatry Dimension

Endometriosis is a widely spread disease that affects about 8% of the world's female population. This condition may be described as a spread of endometrial tissue apart from the uterine cavity, but this process's pathomechanism is still unsure. Apart from classic endometriosis symptoms, which are pelvic pain, infertility, and bleeding problems, there are neuropsychiatric comorbidities that are usually difficult to diagnose. In our review, we attempted to summarize some of them. Conditions like migraine, anxiety, and depression occur more often in women with endometriosis and have a significant impact on life quality and pain perception. Interestingly, 77% of endometriosis patients with depression also have anxiety. Neuroimaging gives an image of the so-called endometriosis brain, which means alternations in pain processing and cognition, self-regulation, and reward. Genetic factors, including mutations in KRAS, PTEN, and ARID1A, influence cellular proliferation, differentiation, and chromatin remodeling, potentially exacerbating lesion severity and complicating treatment. In this review, we focused on the aspects of sciatic and obturator nerve endometriosis, the emotional well-being of endometriosis-affected patients, and the potential influence of endometriosis on dementia, also focusing on prolonged diagnosis. Addressing endometriosis requires a multidisciplinary approach, encompassing molecular insights, innovative therapies, and attention to its psychological and systemic effects.

Nociplastic Pain in Endometriosis: A Scoping Review

Endometriosis is an inflammatory chronic condition associated with nociceptive, neuropathic, and nociplastic pain. Central sensitization (CS) is the primary nociplastic pain mechanism. However, there are currently no standardized methods for detecting CS or nociplastic pain. This review aims to identify available tools for characterizing CS/nociplastic pain in endometriosis-related chronic pelvic pain. Following the PRISMA-P protocol, MEDLINE, Embase, Scopus, and PsychINFO databases were searched on 23 April 2024, for the terms "endometriosis", "central sensitization", "nociplastic pain", "widespread pain", and "assessment tools". Publications were selected if they mentioned tool(s) for detecting nociplastic pain or CS in endometriosis patients. Information was extracted on study demographics, assessment types, and the tools used for detection. Of the 379 citations retrieved, 30 papers met the inclusion criteria. When working to identify CS and nociplastic pain, fourteen studies exclusively used patient-reported questionnaires, six used quantitative sensory testing (QST), two used clinical assessments, and eight used multiple approaches combining patient-reported questionnaires and clinical assessment. This review illustrates the diversity of tools currently used to identify CS and nociplastic pain in endometriosis patients. Further research is needed to evaluate their validity and to standardize methods in order to improve the accuracy of nociplastic pain identification and guide treatment.

Why do oestrogens matter: systematic review and meta-analysis assessing GnRH antagonists, considering add-back therapy, for endometriosis-associated pain

Gonadotrophin-releasing hormone (GnRH) antagonists have been demonstrated to reduce endometriosis-associated pain. Because of the hypo-oestrogenic state they induce, however, higher dosages of GnRH antagonists are not recommended for used long term. This unwanted effect may be eliminated by so-called add-back therapy (ABT). This review was conducted to assess the safety and efficacy of GnRH antagonists, with or without add-back hormonal replacement therapy. Out of the 345 studies selected through the initial search, seven randomized controlled trials were included, comparing different oral GnRH antagonists at varying dosages, from a minimum of 50 mg to a maximum of 200 mg once or twice daily. Women treated with the lowest dose of GnRH antagonists had significantly greater mean pain score reductions from baseline throughout treatment compared with those treated with placebo (odds ratio [OR] -13.12, 95% CI -17.35 to -8.89 and OR -3.08, 95% CI -4.39 to -1.76 for dysmenorrhoea and non-menstrual pelvic pain, respectively). Compatible with the dose-response effect, a positive correlation was found between response rates and adverse event rates. While GnRH antagonists offer an advantage in terms of pain reduction for endometriosis, the more recent literature suggests using GnRH antagonists with ABT, which, while mitigating the hypo-oestrogenic effects of GnRH antagonists, maintain their efficacy, while allowing their long-term use.

Is retrograde menstruation a universal, recurrent, physiological phenomenon? A systematic review of the evidence in humans and non-human primates

STUDY QUESTION

What are the quantitative, qualitative, and temporal patterns of retrograde mentruation?

SUMMARY ANSWER

The extreme quantitative and qualitative heterogeneity of the available studies prevents the definitive conclusion that retrograde menstruation is a universal and consistent phenomenon during the reproductive period.

WHAT IS KNOWN ALREADY

Retrograde menstruation has been defined as a universal, physiological phenomenon that occurs similarly in about 90% of menstruators during the reproductive period. However, uncertainties still exist in terms of the event frequency, total amount, and cellular composition of retrograde menstruation and the differences between individuals with versus those without endometriosis.

STUDY DESIGN SIZE DURATION

Two systematic reviews were performed, one for human studies, and one for non-human primate studies. We retrieved studies from the PubMed and Embase databases published between 1 January 1980 and 1 November 2023. Studies published in the English language were included and identified using a combination of MeSH terms. References from relevant publications were systematically screened and further articles were identified using PubMed's 'similar articles' and 'cited by' functions.

PARTICIPANTS/MATERIALS SETTING METHODS

Results were reported in accordance with the PRISMA guidelines. Studies that did not report original data or provided a review of the field were excluded. Bias analysis was completed for each included human study by using the Newcastle-Ottawa scoring system.

MAIN RESULTS AND THE ROLE OF CHANCE

Fifteen studies were finally included in the human systematic review, mostly with limited sample sizes. The macroscopic visualization of blood in PF during menses was reported with a frequency ranging from 9% to 100%. A prevalence of endometrial cells detected in peritoneal fluid ranging from 8% to 75% was reported in the various studies. Controversial findings were reported in relation to patients with endometriosis. Retrograde menstruation has been evaluated cross-sectionally on single occasions, and no information is available on the course of the phenomenon within an entire cycle and between subsequent cycles. Two studies were included in the non-human primate systematic review; one of them showed that retrograde menstruation was observed more frequently in baboons with naturally occurring endometriosis (83%) than in those with a normal pelvis (51%).

LIMITATIONS REASONS FOR CAUTION

In humans, peritoneal fluid has often been collected at different cycle phases and not systematically during menstruation. The indication for laparoscopy was not always clear for all participants. A wide variety of methods were used to detect endometrial cells, including cytological staining, cell block analysis, immunocytochemistry, and various methods of cell culture.

WIDER IMPLICATION OF THE FINDINGS

The idea that almost all women experience retrograde menstruation regularly and similarly during their reproductive life is currently unsubstantiated. It is an academic notion accepted uncritically. Development of endometriosis may derive from differences in the frequency or severity of the event.

STUDY FUNDING/COMPETING INTERESTS

The review was partially funded by Italian Ministry of Health-Current Research IRCCS. P.Vi. serves as co-editor in Chief of Journal of Endometriosis and Uterine Disorders. E.S. serves as Editor in Chief of Human Reproduction Open and discloses research grants from Ferring, Ibsa, Gedeon Richter, and Theramex, and honoraria from Ibsa and Gedeon Richter. P.Ve. serves as Associate Editor for Human Reproduction Open; is a member of the Editorial Board of the Journal of Obstetrics and Gynaecology Canada, of the Italian Journal of Obstetrics and Gynaecology, and of the International Editorial Board of Acta Obstetricia et Gynecologica Scandinavica; has received royalties from Wolters Kluwer for chapters on endometriosis management in the clinical decision support resource UpToDate; and maintains both a public and private gynecological practice. All other authors declare they have no conflict of interest.

REGISTRATION NUMBER

N/A.

Transgenic mice applications in the study of endometriosis pathogenesis

Endometriosis (EM), characterized by ectopic growth of endometrial tissues and recurrent pelvic pain, is a common disease with severe negative impacts on the life quality of patients. Conventional uterine tissue transplantation-based models have been broadly used to investigate the pathogenic mechanism(s) of EM. Transgenic mice with whole body or uterine/pelvic tissue-specific labelling by the expression of GFP, β-gal or other light-emitting or chromogenic markers enable investigators to analyze the contribution to endometriotic lesions by the donor or recipient side after uterine tissue transplantation. Moreover, when coupled to uterine tissue transplantation, transgenic mice with a specific EM-related gene knocked out or overexpressed make it possible to determine the gene's in vivo role(s) for EM pathogenesis. Furthermore, observations on the rise of de novo endometriotic lesions as well as structural/functional changes in the eutopic endometrium or pelvic tissues after gene manipulation will directly relate the cognate gene to the onset of EM. A major advantage of transgenic EM models is their efficiency for analyzing gene interactions with hormonal, dietetic and/or environmental factors. This review summarizes the features/sources/backgrounds of transgenic mice and their applications to EM studies concerning hormonal regulation, angiogenesis and inflammation. Findings from these studies, the advantages/disadvantages of transgenic EM models, and future expectations are also discussed.

Genetic Links between Endometriosis and Endometriosis-Associated Ovarian Cancer-A Narrative Review (Endometriosis-Associated Cancer)

Endometriosis is a frequent, estrogen-dependent, chronic disease, characterized by the presence of endometrial glands and stroma outside of the uterine cavity. Although it is not considered a precursor of cancer, endometriosis is associated with ovarian cancer. In this review, we summarized the evidence that clear-cell and endometrioid ovarian carcinomas (endometriosis-associated ovarian carcinoma-EAOC) may arise in endometriosis. The most frequent genomic alterations in these carcinomas are mutations in the AT-rich interaction domain containing protein 1A (ARID1A) gene, a subunit of the SWI/SNF chromatin remodeling complex, and alterations in phosphatidylinositol 3-kinase (PI3K) which frequently coexist. Recent studies have also suggested the simultaneous role of the PTEN tumor-suppressor gene in the early malignant transformation of endometriosis and the contribution of deficient MMR (mismatch repair) protein status in the pathogenesis of EAOC. In addition to activating and inactivating mutations in cancer driver genes, the complex pathogenesis of EAOC involves multiple other mechanisms such as the modulation of cancer driver genes via the transcriptional and post-translational (miRNA) modulation of cancer driver genes and the interplay with the inflammatory tissue microenvironment. This knowledge is being translated into the clinical management of endometriosis and EAOC. This includes the identification of the new biomarkers predictive of the risk of endometriosis and cancer, and it will shape the precision oncology treatment of EAOC.

Nerve Bundle Density and Expression of NGF and IL-1β Are Intra-Individually Heterogenous in Subtypes of Endometriosis

Endometriosis is a gynecological disorder associated with local inflammation and neuroproliferation. Increased nerve bundle density has been attributed to increased expression of nerve growth factor (NGF) and interleukin-1β (IL-1β). Immunohistochemical analysis was carried out on 12 patients presenting with all three anatomic subtypes of endometriosis (deep, superficial peritoneal, endometrioma) at surgery, with at least two surgically excised subtypes available for analysis. Immunolocalization for nerve bundle density around endometriosis using protein gene product 9.5 (PGP9.5), as well as NGF and IL-1β histoscores in endometriosis epithelium/stroma, was performed to evaluate differences in scores between lesions and anatomic subtypes per patient. Intra-individual heterogeneity in scores across lesions was assessed using the coefficient of variation (CV). The degree of score variability between subtypes was evaluated using the percentage difference between mean scores from one subtype to another subtype for each marker. PGP9.5 nerve bundle density was heterogenous across multiple subtypes of endometriosis, ranging from 50.0% to 173.2%, where most patients (8/12) showed CV ≥ 100%. The percentage difference in scores showed that PGP9.5 nerve bundle density and NGF and IL-1β expression were heterogenous between anatomic subtypes within the same patient. Based on these observations of intra-individual heterogeneity, we conclude that markers of neuroproliferation in endometriosis should be stratified by anatomic subtype in future studies of clinical correlation.

Association between KRAS and PIK3CA Mutations and Progesterone Resistance in Endometriotic Epithelial Cell Line

Although endometriosis is a benign disease, it is associated with cancer-related gene mutations, such as KRAS or PIK3CA. Endometriosis is associated with elevated levels of inflammatory factors that cause severe pain. In a previous study, we demonstrated that KRAS or PIK3CA mutations are associated with the activation of cell proliferation, migration, and invasion in a patient-derived immortalized endometriotic cell line, HMOsisEC10. In this study, we investigated the effects of these mutations on progesterone resistance. Since the HMOsisEC10 had suppressed progesterone receptor (PR) expression, we transduced PR-B to HMOsisEc10 cell lines including KRAS mutant and PIK3CA mutant cell lines. We conducted a migration assay, invasion assay, and MTT assay using dienogest and medroxyprogestrone acetate. All cell lines showed progesterone sensitivity with or without mutations. Regarding inflammatory factors, real-time quantitative RT-PCR revealed that the KRAS mutation cell line exhibited no suppression of Cox-2 and mPGES-1 on progesterone treatment, whereas IL-6, MCP-1, VEGF, and CYP19A1 were significantly suppressed by progesterone in both mutated cell lines. Our results suggest that KRAS mutation and PIK3CA mutation in endometriotic cells may not be associated with progesterone resistance in terms of aggressiveness. However, KRAS mutations may be associated with progesterone resistance in the context of pain.

Proposal for targeted, neo-evolutionary-oriented secondary prevention of early-onset endometriosis and adenomyosis. Part II: medical interventions

According to consistent epidemiological data, the slope of the incidence curve of endometriosis rises rapidly and sharply around the age of 25 years. The delay in diagnosis is generally reported to be between 5 and 8 years in adult women, but it appears to be over 10 years in adolescents. If this is true, the actual onset of endometriosis in many young women would be chronologically placed in the early postmenarchal years. Ovulation and menstruation are inflammatory events that, when occurring repeatedly for years, may theoretically favour the early development of endometriosis and adenomyosis. Moreover, repeated acute dysmenorrhoea episodes after menarche may not only be an indicator of ensuing endometriosis or adenomyosis, but may also promote the transition from acute to chronic pelvic pain through central sensitization mechanisms, as well as the onset of chronic overlapping pain conditions. Therefore, secondary prevention aimed at reducing suffering, limiting lesion progression, and preserving future reproductive potential should be focused on the age group that could benefit most from the intervention, i.e. severely symptomatic adolescents. Early-onset endometriosis and adenomyosis should be promptly suspected even when physical and ultrasound findings are negative, and long-term ovulatory suppression may be established until conception seeking. As nowadays this could mean using hormonal therapies for several years, drug safety evaluation is crucial. In adolescents without recognized major contraindications to oestrogens, the use of very low-dose combined oral contraceptives is associated with a marginal increase in the individual absolute risk of thromboembolic events. Oral contraceptives containing oestradiol instead of ethinyl oestradiol may further limit such risk. Oral, subcutaneous, and intramuscular progestogens do not increase the thromboembolic risk, but may interfere with attainment of peak bone mass in young women. Levonorgestrel-releasing intra-uterine devices may be a safe alternative for adolescents, as amenorrhoea is frequently induced without suppression of the ovarian activity. With regard to oncological risk, the net effect of long-term oestrogen-progestogen combinations use is a small reduction in overall cancer risk. Whether surgery should be considered the first-line approach in young women with chronic pelvic pain symptoms seems questionable. Especially when large endometriomas or infiltrating lesions are not detected at pelvic imaging, laparoscopy should be reserved to adolescents who refuse hormonal treatments or in whom first-line medications are not effective, not tolerated, or contraindicated. Diagnostic and therapeutic algorithms, including self-reported outcome measures, for young individuals with a clinical suspicion of early-onset endometriosis or adenomyosis are proposed.

Standardized protocol for quantification of nerve bundle density as a biomarker for endometriosis

Introduction

We propose a standardized protocol for measurement of nerve bundle density in endometriosis as a potential biomarker, including in deep endometriosis (DE), ovarian endometriomas (OMA) and superficial peritoneal endometriosis (SUP).

Methods

This was a prospective cohort of surgically excised endometriosis samples from Dec 1st 2013 and Dec 31st 2017 at a tertiary referral center for endometriosis in Vancouver, BC, Canada. Surgical data were available from linked patient registry. Protein gene product 9.5 (PGP9.5) was used to identify nerve bundles on immunohistochemistry. PGP9.5 nerve bundles were counted visually. To calculate nerve bundle density, PGP9.5 nerve bundle count was divided by the tissue surface area (total on the slide). All samples were assessed using NHS Elements software for semi-automated measurement of the tissue surface area. For a subset of samples, high power fields (HPFs) were also counted as manual measurement of the tissue surface area. Intraclass correlation was used to assess intra observer and inter observer reliability. Generalized linear mixed model (GLMM) with random intercepts only was conducted to assess differences in PGP9.5 nerve bundle density by endometriosis type (DE, OMA, SUP).

Results

In total, 236 tissue samples out of 121 participants were available for analysis in the current study. Semi-automated surface area measurement could be performed in 94.5% of the samples and showed good correlation with manually counted HPFs (Spearman's rho = 0.781, p < 0.001). To assess intra observer reliability, 11 samples were assessed twice by the same observer; to assess inter observer reliability, 11 random samples were blindly assessed by two observers. Intra observer reliability and inter observer reliability for nerve bundle density were excellent: 0.979 and 0.985, respectively. PGP9.5 nerve bundle density varied among samples and no nerve bundles could be found in 24.6% of the samples. GLMM showed a significant difference in PGP9.5 nerve bundle density between the different endometriosis types (X2 = 87.6, P < 0.001 after adjusting for hormonal therapy, with higher density in DE and SUP in comparison to OMA).

Conclusion

A standardized protocol is presented to measure PGP9.5 nerve bundle density in endometriosis, which may serve as a biomarker reflecting local neurogenesis in the endometriosis microenvironment.