A Nationwide Cohort Study on the risk of non-gynecological cancers in women with surgically verified endometriosis

Causal effects of endometriosis on cancer risk: A Mendelian randomization study

Endometriosis has been reported in epidemiological studies to be associated with certain types of cancer. However, the presence of reverse causality and residual confounding due to common risk factors introduces uncertainty regarding the extent to which endometriosis itself contributes to the development of cancer. We performed the Mendelian randomization (MR) to investigate the causal associations between endometriosis and 34 different types of cancers. The results of the inverse-variance-weighted (IVW) model suggested that genetic predisposition to endometriosis was causally associated with an increased risk for ovarian cancer (OR = 3.2913; p-value = .0320). The genetic liabilities to endometriosis had causal associations with the decreased risk for skin cancer (OR = 0.9973; p-value = .0219), hematological cancer (OR = 0.9953; p-value = .0175) and ER- breast cancer (OR = 0.6960; p-value = .0381). The causal association of the above combinations were robust by test of heterogeneity and pleiotropy. Together, our study suggests that endometriosis had causal effect on cancer risk.

Development of an Italian National Epidemiological Register on Endometriosis Based on Administrative Data

Background/Objectives: Endometriosis is a female chronic inflammatory disease in which endometrial tissue develops outside the uterine cavity. It is a complex pathology, which significantly contributes to morbidity in premenopausal women, leading to chronic pain, infertility, and subfertility negatively impacting physical and emotional well-being and the overall quality of life. The public health burden of endometriosis remains elusive and challenging to determine, and this uncertainty can lead to inadequate healthcare services and treatments. The objective was to estimate the incidence and prevalence of endometriosis in Italy using the hospital discharge records database via a population-based retrospective study, nationwide between 2011 and 2020. Methods: From the National Hospital Discharge Database, we selected all admissions with a diagnosis of endometriosis (ICD-9-CM, codes 617.x), supported by the presence of a procedure code of laparoscopy or any other surgical procedure allowing for direct visualisation of the lesions. The main outcomes measured: incidence and prevalence of endometriosis were estimated for the entire 2011-2020 period and by individual year, analysing the time trend and variability in different geographical areas of Italy. Results: There were a total of 134,667,646 women aged 15-50 years with one or more hospitalisations for endometriosis in all Italian hospitals. The incidence of endometriosis in Italy during this period was 0.839 per 1000 women (CI95% 0.834-0.844), exhibiting a statistically significant decreasing trend over the years. A discernible north-south gradient was observed, with higher rates documented in the northern regions. The prevalence rate stood at 14.0 per 1000 during the same period, and a similar north-south geographical gradient was identifiable in the prevalence rates as well. Conclusions: The utilization of national-level hospital data enables the generation of incidence and prevalence data for endometriosis without variations in methods and definitions, facilitating the evaluation of temporal trends and regional comparisons. Understanding and quantifying this phenomenon is essential for appropriate healthcare planning in various Italian regions.

Genetically identification of endometriosis and cancers risk in women through a two-sample Mendelian randomization study

Endometriosis is a prevalent and chronic inflammatory gynecologic disorder affecting approximately 6-10% of women globally, and has been associated with an increased risk of cancer. Nevertheless, previous studies have been hindered by methodological limitations that compromise the validity and robustness of their findings. In this study we conducted a comprehensive two-sample Mendelian randomization analysis to explore the genetically driven causal relationship between endometriosis and the risk of cancer. We conducted the analysis via the inverse variance weighted method, MR Egger method, and weighted median method utilizing publicly available genome-wide association study summary statistics. Furthermore, we implemented additional sensitivity analyses to assess the robustness and validity of the causal associations identified. We found strong evidence of a significant causal effect of endometriosis on a higher risk of ovarian cancer via inverse-variance weighted method (OR = 1.19, 95% CI 1.11-1.29, p < 0.0001), MR-Egger regression, and weighted median methodologies. Remarkably, our findings revealed a significant association between endometriosis and an increased risk of clear cell ovarian cancer (OR = 2.04, 95% CI 1.66-2.51, p < 0.0001) and endometrioid ovarian cancer (OR = 1.45, 95% CI 1.27-1.65, p < 0.0001). No association between endometriosis and other types of cancer was observed. We uncovered a causal relationship between endometriosis and an elevated risk of ovarian cancer, particularly clear cell ovarian cancer and endometrioid ovarian cancer. No significant associations between endometriosis and other types of cancer could be identified.

Pain nursing for gynecologic cancer patients

Gynecological malignancy remains a prevalent cause of mortality among women. Chronic cancer pain, as a severe complication of malignancy and its therapies, accounts for a substantial burden of physical and psychological distress in affected patients. Accordingly, early identification, assessment, and standardized management of such pain are crucial in the prevention or delay of its progression. In the present review, we provide a comprehensive overview of the pathological factors that contribute to pain in patients with gynecological malignancy while highlighting the underlying mechanisms of pain in this population. In addition, we summarize several treatment modalities targeting pain management in gynecologic cancer patients, including surgery, radiotherapy, and chemotherapy. These interventions are crucial for tumor elimination and patient survival. Chronic cancer pain exerts a significant impact on wellbeing and quality of life for patients with gynecologic cancer. Therefore, our review emphasizes the importance of addressing this pain and its psychological sequelae and advocates for a multidisciplinary approach that encompasses nursing and psychological support. In summary, this review offers valuable insights into the pathological factors underlying pain, reviews pain management modalities, and stresses the critical role of early intervention and comprehensive care in enhancing the quality of life of these patients.

Female Papillary Thyroid Cancer Survivors Are at Increased Risk of Adenomyosis and Endometrial Hyperplasia

PURPOSE

Thyroid cancer (TC) is the most common endocrine cancer worldwide, affecting mainly women of reproductive age. However, no data exist about its association with endometrial or uterine disorders. This study aimed to assess the risk of hyperproliferative pathology of the reproductive system in female ТС survivors.

METHODS

This was a cross-sectional study of female patients aged 20-45 years diagnosed with papillary TC (PTC) from 1994-2018. Age-matched females with normal thyroid structures served as controls.

RESULTS

One hundred and sixteen patients (mean age 36.7±61 years) and 90 age-matched controls were included. PTC survivors demonstrated an increased risk for adenomyosis [odds ratio (OR) 2.5, 95% confidence interval (CI) 1.3-4.8] and endometrial hyperplasia (OR 3.9, 95% CI 1.1-14.3), compared with controls. The risk for adenomyosis was higher after the ten post-operative years (OR 5.3, 95% CI 2.29- 12.05) than during the first 5-10 years (OR 2.3, 95% CI 1.02-5.10) and increased with the number of RAI courses and the degree of TSH suppression. The risk of endometrial hyperplasia was most evident during the first five years post-thyroidectomy (OR 6.0, 95% CI 1.4-25.5), especially in patients with TSH <0.1 mU/L (OR 6.8, 95% CI 1.4-33.28) No difference in uterine leiomyomas or endometrial polyps was found between PTC survivors and controls.

CONCLUSIONS

Female PTC survivors are at increased risk of endometrial hyperplasia and adenomyosis compared with those with normal thyroid structures.

The association between endometriosis and risk of endometrial cancer and breast cancer: a meta-analysis

Purpose

Endometriosis (EMS) is confirmed pathophysiologically to be an estrogen-dependent disease, similar to endometrial hyperplasia/cancer and breast cancer. Epidemiological and biological data on endometriosis might explain links between endometriosis and these cancers. We sought to identify the differences in the risk of endometrial cancer and breast cancer between women with and women without endometriosis.

Methods

We searched PubMed, EMBASE, the Cochrane Library, and four Chinese databases (CNKI, VIP, WanFang, CBM) to identify relevant studies published online between January 2011 and March 2021. In our meta-analysis, we used the Newcastle–Ottawa Scale (NOS) to evaluate the design and quality of all studies, and we calculated the pooled risk ratio (RR) using the random model. The Q test and I2 were used to evaluate the degree of heterogeneity of eligible studies. We used funnel plots and Begg’s and Egger’s tests to assess publication bias.

Results

Of the 1369 articles, we finally included 14 cohort studies and seven case–control studies. Data from large cohort and case–control studies indicate that women with endometriosis had an increased risk of both endometrial cancer [RR, 1.662; 95% CI, (1.148–2.407)] and breast cancer [RR, 1.082; 95% CI, (1.001–1.169)].

Conclusion

Endometriosis can increase the risk of endometrial cancer and breast cancer, and women with endometriosis are recommended to receive routine screening in long-term management.

Incidence of extraovarian clear cell cancers in women with surgically diagnosed endometriosis: A cohort study

BACKGROUND

Endometriosis is associated with increased risk of clear cell ovarian cancer and has even suggested being an etiological factor for this cancer. Association between endometriosis and extraovarian clear cell cancers is unclear. This study aimed to assess the association between surgically diagnosed endometriosis and risk of extraovarian clear cell cancers according to the type of endometriosis (i.e., ovarian, peritoneal, and other endometriosis) and the site of clear cell cancer.

METHODS

In this register-based historic cohort study we identified all women with surgically diagnosed endometriosis from the Finnish Hospital Discharge Registry 1987-2012. Data on extraovarian clear cell cancers of these women were obtained from the Finnish Cancer Registry. The follow-up started January 1st, 2007 or at endometriosis diagnosis (if later), and ended at emigration, death or on the December 31st, 2014. Standardized incidence ratios were calculated for each site of clear cell carcinoma (intestine, kidney, urinary tract, gynecological organs other than ovary), using the Finnish female population as reference.

RESULTS

The endometriosis cohort consisted of 48,996 women, including 22,745 women with ovarian and 19,809 women with peritoneal endometriosis. Altogether 23 extraovarian clear cell cancers were observed during 367,386 person-years of follow-up. The risk of extraovarian clear cell cancer was not increased among all women with surgically diagnosed endometriosis (standardized incidence ratio 0.89, 95% confidence interval 0.56-1.33) nor in different types of endometriosis. The incidence of clear cell cancer in any specific site was not increased either.

CONCLUSIONS

The risk of extraovarian clear cell cancers in women with surgically diagnosed endometriosis is similar to that in the general population in Finland.

Risk of melanoma in women with endometriosis: A Scottish national cohort study

OBJECTIVE

To explore the risk of melanoma in women with endometriosis.

STUDY DESIGN

A retrospective cohort study using Scottish national population-based data was conducted. The study comprised 281,937 women with nearly 5 million person years (4,923,628) of follow up from 1981 to 2010. 17,834 women with a new surgical diagnosis of endometriosis were compared with 83,303 women with no evidence of endometriosis at laparoscopy, 162,966 women who underwent laparoscopic sterilisation and 17,834 age-matched women from the general population to determine the risk of melanoma. Cox proportional hazards regression was used to calculate crude and adjusted Hazards ratios with 95 % Confidence Intervals.

RESULTS

Women with endometriosis had a significantly higher risk of melanoma when compared to women with no evidence of endometriosis at laparoscopy (HR 1.59, 95 % CI 1.19-2.13), women who had undergone laparoscopic sterilisation (HR 1.82, 95 % CI 1.39-2.40) and age-matched women from the general population (HR 1.63, 95 % CI 1.08-2.45).

CONCLUSION

A diagnosis of endometriosis was associated with an increased risk of developing melanoma compared to those without endometriosis. These findings highlight the need for further research to explore shared pathways in the pathogenesis of the two conditions. It is important to acknowledge that the absolute increase in the risk of melanoma in women with endometriosis remains low, which should be considered when counselling women.

Systematic Review and Meta-Analysis of Incidence and Prevalence of Endometriosis

There is still much controversy regarding the epidemiology of endometriosis. The objective of this work is to conduct a systematic review, and if possible, proceed with a meta-analysis of studies that have analyzed the incidence and prevalence of this condition among women in the general population. The inclusion criteria were papers published after 1997 that had reported data of the incidence or prevalence of endometriosis. The PubMed search engine was used to identify papers meeting the inclusion criteria from 1997 to 2019, with an additional manual search for the identification of potentially eligible studies. The search was limited to papers published in English. The risk of bias was assessed according to the Joanna Briggs Institute Critical Appraisal Checklist. As a result, 27 papers, which included a total of 28,660,652 women, were classified according to the type of design and sources of information in five subgroups. Pooled estimates of prevalence for studies with self-reported data were 0.05 (95% CI: 0.03; 0.06), 0.01 for population-based integrated information systems (95% CI: 0.01; 0.02), and 0.04 (95% CI 0.04; 0.05) in studies using other designs. The pooled incidence rate of endometriosis was: 1.36 per 1000 person-years (PY) (95% CI: 1.09; 1.63) for studies based on hospital discharges, 3.53 per 1000 PY (95% CI: 2.06; 4.99) for cohort studies, and 1.89 per 1000 PY (95% CI: 1.42; 2.37) for population-based integrated information systems. Meta-analysis indicated high heterogeneity based on I-squared statistics. This significant variability may not only be due to methodological issues and the specific limitations of the different designs and data analyzed, including case definitions and subject selection strategies, but also to the inherent heterogeneity of endometriosis. Epidemiological studies with appropriate study designs remain necessary to provide a valid estimation of the population burden of endometriosis.

Endometriosis and cancer: a systematic review and meta-analysis

BACKGROUND

Endometriosis is an often chronic, inflammatory gynaecologic condition affecting 190 million women worldwide. Studies have reported an elevated cancer risk among patients with endometriosis. However, prior research has included methodologic issues that impede valid and robust interpretation.

OBJECTIVE AND RATIONALE

We conducted a meta-analysis of studies investigating the association between endometriosis and cancer risk and analysed the results by methodologic characteristics. We discuss the implications of cancer screening in patients and management challenges faced by clinicians.

SEARCH METHODS

We searched PubMed and Embase databases for eligible studies from inception through 24 October 2019. We included cohort and case-control studies examining the association between endometriosis and cancer risk; cross-sectional studies and case reports were excluded. Publications had to present risk/rate/odds estimates with 95% CI. Random effects meta-analysis was used to estimate summary relative risks (SRR) and CIs. Heterogeneity across studies was assessed by the Q test and I2 statistics, and publication bias using Egger's and Begg's tests. Risk of bias and quality of the included studies were assessed using the risk of bias in non-randomized studies of interventions (ROBINS-I) tool.

OUTCOMES

Forty-nine population-based case-control and cohort studies were included. Twenty-six studies were scored as having a 'serious'/'critical' risk of bias, and the remaining 23 'low'/'moderate'. Cancer-specific analyses showed a positive association between endometriosis and ovarian cancer risk (SRR = 1.93, 95% CI = 1.68-2.22; n = 24 studies) that was strongest for clear cell (SRR = 3.44, 95% CI = 2.82-4.42; n = 5 studies) and endometrioid (SRR = 2.33, 95% CI = 1.82-2.98; n = 5 studies) histotypes (Pheterogeneity < 0.0001), although with significant evidence of both heterogeneity across studies and publication bias (Egger's and Begg's P-values < 0.01). A robust association was observed between endometriosis and thyroid cancer (SRR = 1.39, 95% CI =1.24-1.57; n = 5 studies), a very small association with breast cancer (SRR = 1.04, 95% CI =1.00-1.09; n = 20 studies) and no association with colorectal cancer (SRR = 1.00, 95% CI =0.87-1.16; n = 5 studies). The association with endometrial cancer was not statistically significant (SRR = 1.23, 95% CI =0.97-1.57; n = 17 studies) overall and wholly null when restricted to prospective cohort studies (SRR = 0.99, 95% CI =0.72-1.37; n = 5 studies). The association with cutaneous melanoma was also non-significant (SRR = 1.17, 95% CI =0.97-1.41; n = 7 studies) but increased in magnitude and was statistically significant when restricted to studies with low/moderate risk of bias (SRR = 1.71, 95% CI = 1.24-2.36, n = 2 studies). The most robust finding both in terms of statistical significance and magnitude of effect was an inverse association with cervical cancer (SRR = 0.68, 95% CI =0.56-0.82; n = 4 studies); however, this result has a high potential to reflect heightened access to detection of dysplasia for women who reached an endometriosis diagnosis and is thus likely not causal. Several additional cancer types were explored based on <4 studies.

WIDER IMPLICATIONS

Endometriosis was associated with a higher risk of ovarian and thyroid, and minimally (only 4% greater risk) with breast cancer, and with a lower risk of cervical cancer. However, this meta-analysis confirms that: a majority of studies had severe/critical risk of bias; there is impactful heterogeneity across studies-and for ovarian cancer, publication bias; and causal inference requires temporality, which in many studies was not considered. We discuss the implications of these potential associations from the perspectives of patients with endometriosis, clinicians involved in their care, and scientists investigating their long-term health risks.

Long-term Health Consequences of Endometriosis - Pathways and Mediation by Treatment

Purpose of review

The purpose of this review is to discuss the most up to date research on endometriosis and chronic disease risk, highlighting the role treatments for endometriosis may play in these associations.

Recent findings

Previous studies have shown a consistent association between endometriosis and risk for epithelial ovarian cancer but the association with other cancers is less clear. Current research indicates that endometriosis may in be associated with risk of systemic lupus erythematosus, and potentially other autoimmune diseases. Limited evidence is also present for the association between endometriosis and cardiovascular disease and related conditions (e.g,. hypertension, hypercholesterolemia). A potential explanation for a portion of the increased risk of chronic diseases among women with endometriosis may relate to treatments for endometriosis impacting these outcomes.

Summary

Given the prevalence of endometriosis, understanding the relation between endometriosis and other chronic diseases has the potential to impact the health of many women. However, few high-quality studies with limited biases and adequate follow-up currently exist. Future multi-disciplinary research in prospective cohorts, with ample follow-up time, and detailed information on endometriosis characteristics and treatment is critical to advancing our understanding of this disease and its consequences.

A cohort study of 49 933 women with surgically verified endometriosis: Increased incidence of breast cancer below the age of 40

INTRODUCTION

The association between endometriosis and breast cancer is unclear. We assessed the risk of breast cancer in women with surgically verified endometriosis, with special focus on the age at cancer diagnosis, time from endometriosis diagnosis and breast cancer histology.

MATERIAL AND METHODS

All women with first endometriosis-associated diagnoses occurring concomitantly with relevant surgical codes during 1987-2012 were retrieved from the Finnish Hospital Discharge Register in Finland. Breast cancers diagnosed after the endometriosis diagnosis were identified from the Finnish Cancer Registry. The Finnish female population served as the reference. The endometriosis cohort consisted of 49 933 women (23 210 cases of ovarian, 20 187 peritoneal and 2372 deep infiltrating endometriosis). The outcome measure was the standardized incidence ratio (SIR) with 95% confidence interval (95% CI) of breast cancer calculated for the whole cohort and for the subtypes of endometriosis, stratified by the age at breast cancer diagnosis, histology and time from endometriosis diagnosis.

RESULTS

The overall risk of breast cancer (1555 cases) was similar to the reference population (SIR 0.99; 95% CI 0.94-1.03), did not differ in types of endometriosis, and was similar for ductal and lobular breast cancer. However, the SIR of breast cancer was increased in the age group of 20-29 years (SIR 4.44; 95% CI 2.22-7.94) and in the age group of 30-39 years (SIR 1.28; 95% CI 1.03-1.57). The risk of in situ breast cancer (170 cases) was increased in the entire endometriosis cohort (SIR 1.25; 95% CI 1.07-1.44).

CONCLUSIONS

The overall risk of breast cancer in women with surgically verified endometriosis was similar to that of general population. However, the risk of breast cancer at young age was increased. Young women with surgically verified endometriosis represent highly symptomatic patients with more frequent surgeries and additional therapies that might also contribute to the risk of breast cancer.