Menstrual and reproductive factors and endometrial cancer risk: Results from a population-based case-control study in urban Shanghai

Fetal loss and long-term maternal morbidity and mortality: A systematic review and meta-analysis

BACKGROUND

Evidence suggests common pathways between pregnancy losses and subsequent long-term maternal morbidity, rendering pregnancy complications an early chronic disease marker. There is a plethora of studies exploring associations between miscarriage and stillbirth with long-term adverse maternal health; however, these data are inconclusive.

METHODS AND FINDINGS

We systematically searched MEDLINE, EMBASE, AMED, BNI, CINAHL, and the Cochrane Library with relevant keywords and MeSH terms from inception to June 2023 (no language restrictions). We included studies exploring associations between stillbirth or miscarriage and incidence of cardiovascular, malignancy, mental health, other morbidities, and all-cause mortality in women without previous pregnancy loss. Studies reporting short-term morbidity (within a year of loss), case reports, letters, and animal studies were excluded. Study selection and data extraction were performed by 2 independent reviewers. Risk of bias was assessed using the Newcastle Ottawa Scale (NOS) and publication bias with funnel plots. Subgroup analysis explored the effect of recurrent losses on adverse outcomes. Statistical analysis was performed using an inverse variance random effects model and results are reported as risk ratios (RRs) with 95% confidence intervals (CIs) and prediction intervals (PIs) by combining the most adjusted RR, odds ratios (ORs) and hazard ratios (HRs) under the rare outcome assumption. We included 56 observational studies, including 45 in meta-analysis. There were 1,119,815 women who experienced pregnancy loss of whom 951,258 had a miscarriage and 168,557 stillbirth, compared with 11,965,574 women without previous loss. Women with a history of stillbirth had a greater risk of ischaemic heart disease (IHD) RR 1.56, 95% CI [1.30, 1.88]; p < 0.001, 95% PI [0.49 to 5.15]), cerebrovascular (RR 1.71, 95% CI [1.44, 2.03], p < 0.001, 95% PI [1.92, 2.42]), and any circulatory/cardiovascular disease (RR 1.86, 95% CI [1.01, 3.45], p = 0.05, 95% PI [0.74, 4.10]) compared with women without pregnancy loss. There was no evidence of increased risk of cardiovascular disease (IHD: RR 1.11, 95% CI [0.98, 1.27], 95% PI [0.46, 2.76] or cerebrovascular: RR 1.01, 95% CI [0.85, 1.21]) in women experiencing a miscarriage. Only women with a previous stillbirth were more likely to develop type 2 diabetes mellitus (T2DM) (RR: 1.16, 95% CI [1.07 to 2.26]; p < 0.001, 95% PI [1.05, 1.35]). Women with a stillbirth history had an increased risk of developing renal morbidities (RR 1.97, 95% CI [1.51, 2.57], p < 0.001, 95% [1.06, 4.72]) compared with controls. Women with a history of stillbirth had lower risk of breast cancer (RR: 0.80, 95% CI [0.67, 0.96], p-0.02, 95% PI [0.72, 0.93]). There was no evidence of altered risk of other malignancies in women experiencing pregnancy loss compared to controls. There was no evidence of long-term mental illness risk in women with previous pregnancy losses (stillbirth: RR 1.90, 95% CI [0.93, 3.88], 95% PI [0.34, 9.51], miscarriage: RR 1.78, 95% CI [0.88, 3.63], 95% PI [1.13, 4.16]). The main limitations include the potential for confounding due to use of aggregated data with variable degrees of adjustment.

CONCLUSIONS

Our results suggest that women with a history of stillbirth have a greater risk of future cardiovascular disease, T2DM, and renal morbidities. Women experiencing miscarriages, single or multiple, do not seem to have an altered risk.

The dose-response relationship of pre-menopausal alcohol consumption with age at menopause: a population study of 280 497 women in Norway

BACKGROUND

Previous research suggests that alcohol consumption is associated with high age at menopause. Yet, knowledge about the dose-response relationship is inconsistent. Thus, we studied the pattern of the association of pre-menopausal alcohol consumption with age at natural menopause.

METHODS

We performed a retrospective population-based study using self-reported data from 280 497 women aged 50-69 years attending the Norwegian breast cancer screening programme (BreastScreen Norway) during 2006-15. Associations of weekly alcohol consumption between the age of 20 and 49 years with age at menopause were estimated as hazard ratios (HRs) using Cox proportional hazard models with restricted cubic splines to allow for non-linear associations. We adjusted for year and place of birth, number of childbirths, educational level, body mass index and smoking habits.

RESULTS

Mean age at natural menopause was 51.20 years (interquartile range: 49-54 years). The adjusted HR of reaching menopause was highest for women with no alcohol consumption (reference) and the HR decreased by alcohol consumption up to 50 grams per week (adjusted HR 0.87; 95% CI: 0.86-0.88). Above 50 grams, there was no further decrease in the HR of reaching menopause (P for non-linearity of <0.001).

CONCLUSIONS

Women who did not consume alcohol were youngest at menopause. The lack of a dose-response association among alcohol consumers implies virtually no relation of alcohol consumption with age at menopause. Our findings may suggest that characteristics of the women who did not consume alcohol, not accounted for in the data analyses, explain their younger age at menopause.

Relationship between vitamin D levels and age of menopause and reproductive lifespan: Analysis based on the National health and nutrition examination survey (NHANES) 2001-2018

OBJECTIVES

To determine the association between serum vitamin D levels and age at menopause and reproductive lifespan in a group of US postmenopausal women.

STUDY DESIGN

Data from 6,326 postmenopausal US women in the National Health and Nutrition Examination Survey (NHANES) database 2001-2018 were obtained. Weighted multinomial logistic regression models were used to obtain odds ratios (OR) and 95% confidence intervals (CI). Statistical analyzes were performed using SAS (version 9.4; SAS Institute), and complex survey designs were considered.

RESULTS

Vitamin D deficiency was associated with a higher likelihood of early menopause (OR = 1.34, 95% CI: 1.15, 1.58; p = 0.008) and lower odds of late menopause (OR = 0.79, 95% CI: 0.52, 0.95) in the unadjusted model but not in the adjusted model. Lower vitamin D levels were associated with a higher risk of a shorter reproductive lifespan. The strongest association was seen in the first tertile of vitamin D deficiency (OR = 1.54; 95% CI: 1:29-1:83). After adjustment, the associations were somewhat weakened but remained statistically significant.

CONCLUSIONS

The results of this study suggest that vitamin D deficiency and inadequacy might be associated with earlier age at menopause. It may also reduce the reproductive lifespan in women. Given the cross-sectional nature of the NHANES dataset, these results should be interpreted with caution due to temporality bias. Menopausal age is a multifactorial phenomenon, and the identification of factors and their interactions should be evaluated in future studies.

Pregnancy Loss in Relation to the Risks of Female-Specific Cancers in a Population-Based Cohort and Mendelian Randomization Study - China, 2004-2017

What is already known about this topic?

Limited evidence exists regarding the relationship between pregnancy loss and female-specific cancers within the Chinese population from prospective cohort studies.

What is added by this report?

Terminations were associated with a 13% lower risk of endometrial cancer, whereas stillbirths were related to an 18% higher risk of cervical cancer. Rural residents with a history of pregnancy loss experienced a 19% and 38% increased risk of breast and cervical cancers, respectively, compared to their urban counterparts. Moreover, a positive graded relationship between live births and pregnancy loss on cervical cancer was observed.

What are the implications for public health practice?

This study has significant implications for identifying women at an increased risk for breast and genital cancers and contributes to the development of effective public health strategies for female cancer prevention. Future research on reproductive history, particularly in rural areas, should be given priority in efforts to improve female cancer screening and early detection.

Endometrial cancer risk with menopausal hormone therapy: Health Insurance Database in South Korea-based cohort study

OBJECTIVE

To determine the risk of endometrial cancer according to the types of menopausal hormones used.

METHODS

This retrospective cohort study recruited postmenopausal women older than 40 years from 2003 to 2011, utilizing data from the Korean national health insurance system from 2002 to 2019. The menopausal hormone therapy (MHT) group consisted of women who had been prescribed MHT for greater than 6 months between 2003 and 2011. The non-MHT group consisted of women who had never used menopausal hormones between 2003 and 2011.

RESULTS

A non-MHT group of 1 000 550 women and a MHT group of 353 025 women were chosen. In comparison to never-users, the risk of endometrial cancer was not higher in women who reported last using tibolone (adjusted hazard ratio [aHR] 1.08, 95% confidence interval [CI] 0.96-1.2), combined estrogen plus progestin by the manufacturer (aHR 0.83, 0.72-0.96), combined estrogen plus progestin by the physician (aHR 0.88, 0.7-1.12), and transdermal estrogen (aHR 1.13, 0.36-3.52).

CONCLUSIONS

Tibolone, combined estrogen plus progestin by the physician, and transdermal estrogen do not affect the risk of endometrial cancer. The combination of estrogen plus progestin by the manufacturer decreases the risk of endometrial cancer.

Abortion and Female Cancer Risks among Women Aged 20 to 45 Years: A 10-Year Longitudinal Population-Based Cohort Study in Taiwan

BACKGROUND

Female cancers, including breast, cervical, uterine, and ovarian cancer, remain among the ten most common cancers among women worldwide, but the relationship between female cancers and abortion from previous studies is inconsistent. This study aimed to investigate risks of incident female cancers among women aged 20 to 45 years who underwent abortion in Taiwan compared with those who did not.

METHOD

A longitudinal observational cohort study was conducted using three nationwide population-based databases in Taiwan, focusing on 20- to 45-year-old women, with 10 years of follow-up. Matched cohorts were identified with propensity score 1-to-3 matching between 269,050 women who underwent abortion and 807,150 who did not. Multivariable Cox proportional hazard modeling was used for analysis after adjusting for covariates including age, average monthly payroll, fertility, diabetes mellitus, polycystic ovarian syndrome, endometrial hyperplasia, endometriosis, hormone-related drugs, and Charlson comorbidity index.

RESULTS

We found lower risk of uterine cancer (hazard ratio [HR]: 0.77, 95% CI: 0.70-0.85) and ovarian cancer (HR: 0.81, 95% CI: 0.75-0.88), but no significant difference in risk of breast cancer or cervical cancer, among matched abortion compared with non-abortion cohorts. Regarding subgroup analysis, cervical cancer risk was higher for parous women who underwent abortion, and uterine cancer risk was lower for nulliparous women who underwent abortion compared with non-abortion groups.

CONCLUSIONS

Abortion was related to lower uterine and ovarian cancer risk but was not associated with risks of incident breast cancer or cervical cancer. Longer follow-up may be necessary to observe risks of female cancers at older ages.

Epidemiological trends and risk factors of gynecological cancers: an update

Gynecological cancers, the most common cancer among women worldwide, disrupt the function of women's reproductive system, significantly impacting the quality of life. The epidemiological patterns of gynecological cancers differ in various regions and alter over time. The main challenge to deal with women's cancers is focusing on potential plans to improve patient outcomes. The epidemiology and general risk elements of gynecological cancers are important in the management of these cancers, so all of the reported risk factors in gynecological cancers have been evaluated in the present review. Due to the role of gynecological cancers in women's health, preventive measures and modifiable lifestyles together with early detection in high-risk groups are effective strategies that can reduce mortality rates. This review summarizes the epidemiology and global risk factors of gynecological cancers alongside others to better management of these malignancies and improve the quality of life in the affected patients.

Development of MRI-based radiomics predictive model for classifying endometrial lesions

An unbiased and accurate diagnosis of benign and malignant endometrial lesions is essential for the gynecologist, as each type might require distinct treatment. Radiomics is a quantitative method that could facilitate deep mining of information and quantification of the heterogeneity in images, thereby aiding clinicians in proper lesion diagnosis. The aim of this study is to develop an appropriate predictive model for the classification of benign and malignant endometrial lesions, and evaluate potential clinical applicability of the model. 139 patients with pathologically-confirmed endometrial lesions from January 2018 to July 2020 in two independent centers (center A and B) were finally analyzed. Center A was used for training set, while center B was used for test set. The lesions were manually drawn on the largest slice based on the lesion area by two radiologists. After feature extraction and feature selection, the possible associations between radiomics features and clinical parameters were assessed by Uni- and multi- variable logistic regression. The receiver operator characteristic (ROC) curve and DeLong validation were employed to evaluate the possible predictive performance of the models. Decision curve analysis (DCA) was used to evaluate the net benefit of the radiomics nomogram. A radiomics prediction model was established from the 15 selected features, and were found to be relatively high discriminative on the basis of the area under the ROC curve (AUC) for both the training and the test cohorts (AUC = 0.90 and 0.85, respectively). The radiomics nomogram also showed good performance of discrimination for both the training and test cohorts (AUC = 0.91 and 0.86, respectively), and the DeLong test shows that AUCs were significantly different between clinical parameters and nomogram. The result of DCA demonstrated the clinical usefulness of this novel nomogram method. The predictive model constructed based on MRI radiomics and clinical parameters indicated a highly diagnostic efficiency, thereby implying its potential clinical usefulness for the precise identification and prediction of endometrial lesions.

The relation of number of childbirths with age at natural menopause: a population study of 310 147 women in Norway

STUDY QUESTION

Does age at natural menopause increase with increasing of number of childbirths?

SUMMARY ANSWER

Age at menopause increased with increasing number of childbirths up to three childbirths; however, we found no further increase in age at menopause beyond three childbirths.

WHAT IS KNOWN ALREADY

Pregnancies interrupt ovulation, and a high number of pregnancies have therefore been assumed to delay menopause. Previous studies have had insufficient statistical power to study women with a high number of childbirths. Thus, the shape of the association of number of childbirths with age at menopause remains unknown.

STUDY DESIGN, SIZE, DURATION

A retrospective population study of 310 147 women in Norway who were 50–69 years old at data collection.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The data were obtained by two self-administered questionnaires completed by women attending BreastScreen Norway, a population-based screening program for breast cancer. The associations of number of childbirths with age at menopause were estimated as hazard ratios by applying Cox proportional hazard models, adjusting for the woman’s year of birth, cigarette smoking, educational level, country of birth, oral contraceptive use and body mass index.

MAIN RESULTS AND THE ROLE OF CHANCE

Women with three childbirths had the highest mean age at menopause (51.36 years; 95% CI: 51.33–51.40 years), and women with no childbirths had the lowest (50.55 years; 95% CI: 50.48–50.62 years). Thus, women with no childbirths had higher hazard ratio of reaching menopause compared to women with three childbirths (reference group) (adjusted hazard ratio, 1.24; 95% CI: 1.22–1.27). Beyond three childbirths, we estimated no further increase in age at menopause. These findings were confirmed in sub-analyses among (i) women who had never used hormonal intrauterine device and/or systemic menopausal hormonal therapy; (ii) women who were born before 1950 and (iii) women who were born in 1950 or after.

LIMITATIONS, REASONS FOR CAUTION

Information about age at menopause was based on self-reports.

WIDER IMPLICATIONS OF THE FINDINGS

If pregnancies truly delay menopause, one would expect that women with the highest number of childbirths had the highest age at menopause. Our results question the assumption that interrupted ovulation during pregnancy delays menopause.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the South-Eastern Norway Regional Health Authority [2016112 to M.S.G.] and by the Norwegian Cancer Society [6863294-2015 to E.K.B.]. The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Polymorphisms of the TNF, LTA, and TNFRSF1B genes are associated with onsets of menarche and menopause in US women of European ancestry

BACKGROUND

The TNF, LTA and TNFRSF1B genes have been implicated in various traits related to menarche and menopause.

AIM

To analyse the TNF, LTA and TNFRSF1B genes for their association with ages at menarche (AM) and natural menopause (ANM).

SUBJECTS AND METHODS

The study sample consisted of 314 unrelated females of European ancestry. Twenty SNPs located in and near the genes were analysed using various statistical methods. In addition, the functional significance of the loci associated with AM and ANM was analysed in silico.

RESULTS

Locus rs2229094 of the LTA gene was associated with AM according to the additive (β = -0.295, p_perm = 0.016) and recessive (β = -0.940, p_perm = 0.016) genetic models. Haplotype GG rs1148459-rs590368 of the TNFRSF1B gene was associated with AM (β = 0.307, p_perm = 0.023). Haplotype GCA rs2844484-rs2229094-rs1799964 was associated with ANM after adjustment for covariates (β = -1.020, p_perm = 0.035). All studied loci were associated with ANM after adjustment for breastfeeding (raw p < 0.05). In addition, eight of the most significant models of interlocus interactions were associated with AM and five with ANM.

CONCLUSION

The results of the present study suggest that the TNF, LTA and TNFRSF1B genes are associated with AM and ANM.

Statistical Meta-Analysis of Risk Factors for Endometrial Cancer and Development of a Risk Prediction Model Using an Artificial Neural Network Algorithm

Simple Summary

A robust and comprehensive meta-analysis, for the first time, identified definitely that BMI is by far the most influential risk factor in endometrial cancer. Risk factors were previously only studied individually and or in smaller meta-analysis studies which grouped some factors together. BMI was shown to be an important risk factor with other factors less so, but no rank order was established. This work also offers, for the first time, a neural network computer model to predict the overall increase or decreased risk of cancer for individual patients, which is 98.6% accurate. This prediction can be used as a tool to determine if a patient should be considered for testing and to predict diagnosis, as well as to suggest prevention measures to patients.

Abstract

Objectives: In this study we wished to determine the rank order of risk factors for endometrial cancer and calculate a pooled risk and percentage risk for each factor using a statistical meta-analysis approach. The next step was to design a neural network computer model to predict the overall increase or decreased risk of cancer for individual patients. This would help to determine whether this prediction could be used as a tool to decide if a patient should be considered for testing and to predict diagnosis, as well as to suggest prevention measures to patients. Design: A meta-analysis of existing data was carried out to calculate relative risk, followed by design and implementation of a risk prediction computational model based on a neural network algorithm. Setting: Meta-analysis data were collated from various settings from around the world. Primary data to test the model were collected from a hospital clinic setting. Participants: Data from 40 patients notes currently suspected of having endometrial cancer and undergoing investigations and treatment were collected to test the software with their cancer diagnosis not revealed to the software developers. Main outcome measures: The forest plots allowed an overall relative risk and percentage risk to be calculated from all the risk data gathered from the studies. A neural network computational model to determine percentage risk for individual patients was developed, implemented, and evaluated. Results: The results show that the greatest percentage increased risk was due to BMI being above 25, with the risk increasing as BMI increases. A BMI of 25 or over gave an increased risk of 2.01%, a BMI of 30 or over gave an increase of 5.24%, and a BMI of 40 or over led to an increase of 6.9%. PCOS was the second highest increased risk at 4.2%. Diabetes, which is incidentally also linked to an increased BMI, gave a significant increased risk along with null parity and noncontinuous HRT of 1.54%, 1.2%, and 0.56% respectively. Decreased risk due to contraception was greatest with IUD (intrauterine device) and IUPD (intrauterine progesterone device) at −1.34% compared to −0.9% with oral. Continuous HRT at −0.75% and parity at −0.9% also decreased the risk. Using open-source patient data to test our computational model to determine risk, our results showed that the model is 98.6% accurate with an algorithm sensitivity 75% on average. Conclusions: In this study, we successfully determined the rank order of risk factors for endometrial cancer and calculated a pooled risk and risk percentage for each factor using a statistical meta-analysis approach. Then, using a computer neural network model system, we were able to model the overall increase or decreased risk of cancer and predict the cancer diagnosis for particular patients to an accuracy of over 98%. The neural network model developed in this study was shown to be a potentially useful tool in determining the percentage risk and predicting the possibility of a given patient developing endometrial cancer. As such, it could be a useful tool for clinicians to use in conjunction with other biomarkers in determining which patients warrant further preventative interventions to avert progressing to endometrial cancer. This result would allow for a reduction in the number of unnecessary invasive tests on patients. The model may also be used to suggest interventions to decrease the risk for a particular patient. The sensitivity of the model limits it at this stage due to the small percentage of positive cases in the datasets; however, since this model utilizes a neural network machine learning algorithm, it can be further improved by providing the system with more and larger datasets to allow further refinement of the neural network.

Distinct clinical and genetic mutation characteristics in sporadic and Lynch syndrome-associated endometrial cancer in a Chinese population

BACKGROUND

The diagnosis of Lynch syndrome-associated endometrial cancer patients is significant for early warning of their relatives. The purpose of this study was to provide diagnostic indicators of Lynch syndrome-associated endometrial cancer by screening the differential clinical and genetic characteristics.

METHODS

Clinical information and hysterectomy specimens were collected from 377 eligible patients with endometrial cancer. The MLH1 methylation level was detected by an EZ DNA Methylation-Gold Kit. According to the above experimental results, the patients were then divided into sporadic endometrial cancer and suspected Lynch syndrome-associated endometrial cancer groups. A total of 62 samples were randomly selected for whole-exome sequencing. IBM SPSS Statistics 21 was used to compare the clinical data between the sporadic and suspected Lynch syndrome-associated endometrial cancer groups, and the relationship between the specific high-frequency-mutation genes and the clinical data.

RESULTS

According to the results of MMR immunohistochemistry and MLH1 methylation, the sporadic endometrial cancer group included 361 patients and the suspected Lynch syndrome-associated endometrial cancer group included 16 patients in this study. In the clinical analysis, the average age of the suspected Lynch syndrome-associated endometrial cancer patients was 45.50 ± 11.50 years, which was significantly younger than the 51.17 ± 10.03 years of the sporadic endometrial cancer patients (P = 0.028). The average BMI of the suspected Lynch syndrome-associated endometrial cancer patients was 23.43 kg/m² (CI: 20, 30), which was lower than the 26.50 kg/m² of the sporadic endometrial cancer patients (P = 0.028). Combined with the WES data, MASP2, NADK and RNF223 were identified as three specific mutation sites related to age, FIGO stage and histology.

CONCLUSIONS

Compared with the suspected endometrial cancer patients, the Lynch syndrome-associated endometrial cancer patients were younger and less obese. Mutations in MASP2, NADK and RNF223 might be regarded as genetic endometrial cancer features related to clinical characteristics.

Pregnancy outcomes and risk of endometrial cancer: A pooled analysis of individual participant data in the Epidemiology of Endometrial Cancer Consortium

A full-term pregnancy is associated with reduced endometrial cancer risk; however, whether the effect of additional pregnancies is independent of age at last pregnancy is unknown. The associations between other pregnancy-related factors and endometrial cancer risk are less clear. We pooled individual participant data from 11 cohort and 19 case-control studies participating in the Epidemiology of Endometrial Cancer Consortium (E2C2) including 16 986 women with endometrial cancer and 39 538 control women. We used one- and two-stage meta-analytic approaches to estimate pooled odds ratios (ORs) for the association between exposures and endometrial cancer risk. Ever having a full-term pregnancy was associated with a 41% reduction in risk of endometrial cancer compared to never having a full-term pregnancy (OR = 0.59, 95% confidence interval [CI] 0.56-0.63). The risk reduction appeared the greatest for the first full-term pregnancy (OR = 0.78, 95% CI 0.72-0.84), with a further ~15% reduction per pregnancy up to eight pregnancies (OR = 0.20, 95% CI 0.14-0.28) that was independent of age at last full-term pregnancy. Incomplete pregnancy was also associated with decreased endometrial cancer risk (7%-9% reduction per pregnancy). Twin births appeared to have the same effect as singleton pregnancies. Our pooled analysis shows that, while the magnitude of the risk reduction is greater for a full-term pregnancy than an incomplete pregnancy, each additional pregnancy is associated with further reduction in endometrial cancer risk, independent of age at last full-term pregnancy. These results suggest that the very high progesterone level in the last trimester of pregnancy is not the sole explanation for the protective effect of pregnancy.

Temporal trends in age at menarche and age at menopause: a population study of 312 656 women in Norway

STUDY QUESTION

Have mean age at menarche or mean age at natural menopause changed from the 1939 birth cohort to the 1964 birth cohort?

SUMMARY ANSWER

We estimated a minor decrease in mean age at menarche and an increase by nearly 3 years in mean age at natural menopause.

WHAT IS KNOWN ALREADY

In the Western world, age at menarche decreased across birth cohorts from the early 1800s until the 1950s. Whether mean age at menarche has continued to decrease in birth cohorts after the 1950s remains uncertain. It is also uncertain whether mean age at natural menopause has changed across birth cohorts.

STUDY DESIGN, SIZE, DURATION

We performed a retrospective population study of 312 656 women who were born in Norway during the years 1936–1964.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The data were obtained by two self-administered questionnaires from women who participated in the Norwegian breast cancer screening program (BreastScreen Norway) during the years 2006–2014. We used flexible parametric survival models with restricted cubic splines to estimate mean age at menarche, mean age at menopause and mean number of years between menarche and menopause according to the women’s year of birth. The women who were still having menstrual periods contributed with follow-up time until the time of data collection, and the women who had reported surgical removal of the uterus and/or both ovaries prior to natural menopause contributed with follow-up time until the time of surgery.

MAIN RESULTS AND THE ROLE OF CHANCE

The mean age at menarche was 13.42 years (95% CI: 13.40–13.44 years) among women born during 1936–1939, and it was 13.24 years (95% CI: 13.22–13.25 years) among women born during 1960–1964. The mean age at natural menopause increased from 50.31 years (95% CI: 50.25–50.37 years) among women born during 1936–1939 to 52.73 years (95% CI: 52.64–52.82 years) among women born during 1960–1964. The mean number of years between menarche and menopause increased from 36.83 years (95% CI: 36.77–36.89 years) to 40.22 years (95% CI: 40.11–40.34 years).

LIMITATIONS, REASONS FOR CAUTION

Information about age at menarche and age at menopause was based on self-reports.

WIDER IMPLICATIONS OF THE FINDINGS

Late menopause is associated with increased risk of breast cancer but also with increased life expectancy. Thus, higher mean age at menopause may partly explain the increase in breast cancer incidence after menopause and the increase in life expectancy in recent time. Also, a longer interval between menarche and menopause could suggest that the number of years of female fecundity has increased.

STUDY FUNDING/COMPETING INTEREST(S)

This work was funded by the South-Eastern Norway Regional Health Authority [grant number 2016112 to M.S.G.] and by the Norwegian Cancer Society [grant number 6863294-2015 to E.K.B.]. The authors declare no conflicts of interest.

Racial/ethnic differences in anthropometric and hormone-related factors and endometrial cancer risk: the Multiethnic Cohort Study

BACKGROUND

Anthropometric and hormone-related factors are established endometrial cancer risk factors; however, little is known about the impact of these factors on endometrial cancer risk in non-White women.

METHODS

Among 110,712 women participating in the Multiethnic Cohort (MEC) Study, 1150 incident invasive endometrial cancers were diagnosed. Hazard ratios (HRs) and 95% confidence intervals (CIs) for associations with endometrial cancer risk for race/ethnicity and for risk factors across racial/ethnic groups were calculated.

RESULTS

Having a higher body mass index (BMI) at baseline or age 21 years was strongly associated with increased risk (p_int race/ethnicity ≥ 0.36). Parity (vs nulliparity) was inversely associated with risk in all the groups except African Americans (p_int 0.006). Current use of postmenopausal hormones at baseline (PMH-E; vs never use) was associated with increased risk in Whites and Japanese Americans (p_int 0.002). Relative to Whites, endometrial cancer risk was lower in Japanese Americans and Latinas and non-significantly higher in Native Hawaiians. Risk in African Americans did not differ from that in Whites.

CONCLUSIONS

Racial/ethnic differences in endometrial cancer risk were not fully explained by anthropometric or hormone-related risk factors. Further studies are needed to identify reasons for the observed racial/ethnic differences in endometrial cancer risk.

Endometrial cancer-is our knowledge changing?

In developed countries, endometrial cancer (EC) is the most frequent gynecologic malignancy in postmenopausal women. At the same time, EC has become one of the most common cancers in numerous developing countries, probably influenced by global epidemic of obesity. The majority of patients have low-grade endometrioid cancer with a high 5-year survival rate, but with high-risk EC, the survival rates are still rather low. However, despite intensive research in last decades, our knowledge of the mechanisms, risk factors, diagnosis and treatment have not significantly improved. The standard treatment of all types of EC is still a traditional combination of surgery, irradiation and/or chemotherapy, despite the fact that each of these options is not without having some negative side effects. Despite the fact that on the molecular level, EC is relatively well-studied, but the efforts to transform these findings into either diagnosis or therapies of EC remain elusive. In addition, some research into risk factors involved in the development or progression of EC seems to be more a fishing expedition than a well thought-out approach. The purpose of this review is to summarize the most recent developments in the search for biomarkers and prognostic markers and to discuss the progress in EC treatment.

Using Circadian Rhythm Patterns of Continuous Core Body Temperature to Improve Fertility and Pregnancy Planning

Objective

Review relationships among circadian clocks, core body temperature (CBT), and fertility in women.

Methods

Scoping literature review.

Results

Circadian clocks are a ubiquitous adaptation to the most predictable environmental events - the daily cycles of light and dark. Core body temperature (CBT) also follows a circadian rhythm. Additionally, CBT is tightly controlled by a combination of neuronal circuits that begin in the hypothalamus and involve many other portions of the brain as well as a wide range of peripheral mechanisms. In women with normal reproductive function, the diurnal temperature pattern for CBT is strongly influenced by the menstrual cycle of reproductive hormones, primarily estradiol and progesterone, which modulate the activity of hypothalamic neural circuits involved in body temperature control, resulting in an infradian CBT rhythm.

Conclusions

Analysis of CBT via continuous recording reveals patterns in the interactions of circadian and infradian CBT rhythms capable of accurately predicting the fertility window and hormonal patterns suggesting oligo-ovulation and subfertility. New wearable technologies can facilitate employment of hormone-associated changes in CBT for pregnancy planning and offer clinical insight to infertility and menopause.

Risk factors for endometrial carcinoma among postmenopausal women in Sri Lanka: a case control study

Background

Endometrial carcinoma burden is on the rise globally. The objective of this study was to determine the risk factors for endometrial carcinoma among postmenopausal women in Western province in Sri Lanka.

Methods

A case control study was conducted recruiting 83 incident cases of endometrial carcinoma and 332 unmatched hospital controls from all the secondary and tertiary care hospitals in the province using consecutive sampling technique. A case was defined as a postmenopausal woman who had been residing in the province for at least a period of 1 year, diagnosed to have endometrial carcinoma with histological confirmation within 3 months of the initiation of data collection of the study. Data were collected using validated interviewer administered questionnaire. Risk factor were identified through multiple logistic regression and results were expressed as adjusted odds ratios (AOR) and 95% confidence intervals (CI).

Results

The independent risk factors of endometrial carcinoma are having family history of any type of cancer among first degree relative (AOR = 12.6; 95% CI:5.14–30.9), generalized obesity (BMI ≥25 kg/m²) (AOR = 11.85; 95% CI:5.12–27.4), never conceived (AOR = 3.84; 95% CI:1.37–10.7), age at menarche ≤11 years (AOR = 4.07; 95% CI:1.16–14.2), age > 55 years (AOR = 4.69; 95% CI:2.16–10.2), monthly family income of ≤20,000 Rupees (AOR = 2.65; 95% CI:1.31–5.39), sub-optimal consumption of deep fried food (AOR = 0.17; 95% CI:0.06–0.46), and low level household activities (AOR = 2.82; 95% CI:1.34–5.92).

Conclusions

There were eight independent risk factors of endometrial carcinoma specific for Sri Lankan postmenopausal women identified. Some modifiable risk factors such as generalized obesity, sub-optimal dietary practices and low level physical activities need to be addressed at primary prevention level.

An Israeli Gynecologic Oncology Group study of statin use and endometrial cancer prognosis

OBJECTIVE

To assess whether statin use by endometrial cancer patients was associated with a survival advantage.

METHODS

A retrospective chart review study, by the Israeli Gynecologic Oncology Group, of consecutive endometrial cancer patients who underwent surgery in one of 11 medical centers between 2002 and 2014. Clinical and pathological reports, and measures of survival were compared between statin users and nonusers. Kaplan-Meier and Cox proportional hazard models were used to assess the effect of using statins on survival measures.

RESULTS

Over a mean follow-up period of 6.2 years (range, 1-12 years) for 2017 endometrial cancer patients with complete data, 663 (32.8%) used statins prior to diagnosis and 1354 (67.1%) did not. No statistically significant differences between the groups were observed for most demographic and clinical characteristics. There was no difference between statin users and nonusers in 5-year recurrence-free survival (82% vs 83%; P=0.508), disease-specific survival (86% vs 84%; P=0.549), or overall survival (77% vs 75%; P=0.901).

CONCLUSIONS

In this large cohort of patients with endometrial cancer, no significant associations were found between use of statins and endometrial cancer survival.

Age at Menopause and Risk of Developing Endometrial Cancer: A Meta-Analysis

Object

The association of age at menopause with endometrial cancer remains controversial. Therefore, we quantitatively summarized the evidence from observational studies with a meta-analysis.

Methods

We searched PubMed, Web of Science, Embase, Medline, Chinese National Knowledge Infrastructure (CNKI), and Wan Fang Med online up to March 2019, and all eligible case-control and cohort studies were included in the study. Pooled relative risks (RRs) with 95% confidence intervals (CIs) were calculated using the random-effects model. The dose-response relationship was assessed by restricted cubic spline model. The heterogeneity among studies was evaluated by I². Metaregression was used to explore the potential sources of between-study heterogeneity. Egger's test was used to estimate publication bias.

Results

Eighteen articles including 957242 subjects with 4781 cases were included in the meta-analysis. The pooled RR (95%CI) of endometrial cancer for the highest versus the lowest age at menopause was 1.89 (95%CI: 1.58-2.26). For dose-response analysis, a nonlinear relationship was found between age at menopause and endometrial cancer, and the positive association became statistically significant when age at menopause was greater than 46.5 years old.

Conclusions

This meta-analysis suggested that age at menopause was positively associated with endometrial cancer. For women whose menopausal age over 46.5 years old, the risk of endometrial cancer increased with the age at menopause.

Impaired redox regulation of estrogen metabolizing proteins is important determinant of human breast cancers

Estrogen evidently involves critically in the pathogenesis of gynaecological-cancers. Reports reveal that interference in estrogen-signalling can influence cell-cycle associated regulatory-processes in female reproductive-organs. The major determinants that influence E2-signallings are estrogen-receptor (ER), estrogen-sulfotransferase (SULT1E1), sulfatase (STS), and a formylglycine-generating-enzyme (FGE) which regulates STS activity. The purpose of this mini review was to critically analyze the correlation between oxidative-threats and redox-regulation in the process of estrogen signalling. It is extensively investigated and reported that oxidative-stress is linked to cancer. But no definite mechanism has been explored till date. The adverse effects of oxidative-threat/free-radicals (like genotoxic-effects, gene-regulation, and mitochondrial impairment) have been linked to several diseases like diabetes/cardiovascular-syndrome/stroke and cancer. However, a significant correlation between oxidative-stress and gynaecological-cancers are repeatedly reported without pointing a definite mechanism. For the first time in our study we have investigated the relationship between oxidative stress and the regulation of estrogen via estrogen metabolizing proteins. Reports reveal that ER, SULT1E1, STS and FGE are target-molecules of oxidative-stress and may function differently in oxidizing and reducing environment. In addition, estrogen itself can induce oxidative-stress. This fact necessitates identifying the critical connecting events between oxidative-stress and regulation of estrogen-associated-molecules (ER, SULT1E1, STS, and FGE) that favors tumorigenesis/carcinogenesis. The current review focus is on unique redox-regulation of estrogen and its regulatory-molecules via oxidative-stress. This mechanistic-layout may identify new therapeutic-targets and open further scopes to treat gynecological-cancers more effectively.

Diet, menopause and the risk of ovarian, endometrial and breast cancer

Menopause, the permanent cessation of the menstrual cycle, marks the end of a woman's reproductive lifespan. In addition to changes in sex hormone levels associated with menopause, its timing is another predictor of future health outcomes such as duration of the presence of vasomotor symptoms (VMS) and the risk of hormone-related cancers. With ageing of the population, it is estimated that worldwide 1·2 billion women will be menopausal by the year 2030. Previously the effects of reproductive factors (e.g. parity, age at menarche, pregnancy) and socio-demographic factors on intermediate and long-term health outcomes of menopause have been widely documented. However, little is known about whether diet could have an impact on these. Therefore, we review current evidence on the associations of diet with menopause, presence of VMS and the risk of hormone-related cancers such as ovarian, endometrial and breast cancer. Dietary factors could influence the lifespan of the ovaries and sex-hormones levels, hence the timing of natural menopause. Few studies reported an association between diet, in particular soya consumption, and a reduced risk of VMS. Sustained oestrogen exposure has been associated with a higher risk of hormone-related cancers and thus high-fat and meat diets have been linked with an increased risk of these cancers. However, to better understand the mechanistic pathways involved and to make stronger conclusions for these relationships, further studies investigating the associations of dietary intakes and dietary patterns with menopause, presence of VMS and the risk of hormone-related cancers are required.

Age at First Birth and the Risk of Endometrial Cancer Incidence: A Pooled Analysis of Two Prospective Cohort Studies among Japanese Women

Background: Age at first birth has been increasing among women in developed countries. Meanwhile, endometrial cancer has also been increasing worldwide, being one of the most common female hormone-related cancers. The purpose of this study was to examine the association between age at first birth and the risk of endometrial cancer among Japanese women, and to examine the hypothesis that the recent increase in endometrial cancer incidence can be partly explained by the trend for increasing age at first birth.

Methods: We conducted a pooled analysis of two prospective studies among residents in Miyagi Prefecture in rural northern in Japan. The Miyagi Cohort Study started in 1990 and included 21,455 parous women. The Ohsaki Cohort Study started in 1994 and included 17,287 parous women. The subjects responded to a self-administrated questionnaire including reproductive factors such as age at first birth. Incident cases of cancer were identified through linkage to the Miyagi Prefectural Cancer Registry, which covers the study area.

Results: In a consortium of two prospective studies with 598,933 person-years, we identified 105 incident case of endometrial cancer. Compared with women aged 22 years or less at first birth, multivariate hazard ratios (HRs) and 95% confidence intervals (CIs) for the risk of endometrial cancer were 0.79 (0.49-1.26) for women aged 23 to 25 years at first birth, and 0.53 (0.28-1.00) for those aged 26 years and older (p-trend<0.05).

Conclusion: This pooled analysis of two prospective studies does not support the hypothesis that the recent increase in the incidence of endometrial cancer can be partly explained by the increase in the age at first birth.

Hormone Replacement Therapy: Would it be Possible to Replicate a Functional Ovary?

Background: Throughout history, menopause has been regarded as a transition in a woman’s life. With the increase in life expectancy, women now spend more than a third of their lives in menopause. During these years, women may experience intolerable symptoms both physically and mentally, leading them to seek clinical advice. It is imperative for healthcare providers to improve the quality of life by reducing bothersome menopausal symptoms and preventing disorders such as osteoporosis and atherosclerosis. The current treatment in the form of hormone replacement therapy (HRT) is sometimes inadequate with several limitations and adverse effects. Objective and rationale: The current review aims to discuss the need, efficacy, and limitations of current HRT; the role of other ovarian hormones, and where we stand in comparison with ovary-in situ; and finally, explore towards the preparation of an HRT model by regeneration of ovaries tissues through stem cells which can replicate a functional ovary. Search methods: Four electronic databases (MEDLINE, Embase, Web of Science and CINAHL) were searched from database inception until 26 April 2018, using a combination of relevant controlled vocabulary terms and free-text terms related to ‘menopause’, ‘hormone replacement therapy’, ‘ovary regeneration’, ‘stem cells’ and ‘ovarian transplantation’. Outcomes: We present a synthesis of the existing data on the efficacy and limitations of HRT. HRT is far from adequate in postmenopausal women with symptoms of hormone deprivation as it fails to deliver all hormones secreted by naïve ovarian tissue. Moreover, the pharmacokinetics of synthetic hormones makes them substantially different from natural ones. Not only does the number and type of hormones given in HRT matter, but the route of delivering and their release in circulation are also imperative. The hormones are delivered either orally or topically in a non-physiological uniform manner, which brings along with it several side effects. These identify the need for a hormone delivery system which replicates, integrates and reacts as per the requirement of the female body. Wider implications: The review outlines the strengths and weaknesses of HRT and highlights the potential areas for future research. There is a tremendous potential for research in this field to understand the collective roles of the various ovarian hormones and to devise an auto-regulated hormone delivery system which replicates the normal physiology. Its clinical applications can prove to be transformative for postmenopausal women helping them to lead a healthy and productive life.

Lifetime number of years of menstruation as a risk index for postmenopausal endometrial cancer in the Norwegian Women and Cancer Study

INTRODUCTION

Lifetime number of years of menstruation (LNYM) reflects a woman's cumulative exposure to endogenous estrogen and can be used as a measure of the combined effect of reproductive factors related to endometrial cancer (EC) risk.

MATERIAL AND METHODS

We aimed to study the association between LNYM and EC risk among postmenopausal women and calculate the population attributable fraction of EC for different LNYM categories. Our study sample consisted of 117 589 women from the Norwegian Women and Cancer (NOWAC) Study. All women were aged 30-70 years at enrollment and completed a baseline questionnaire between 1991 and 2006. Women were followed up for EC to December 2014 through linkages to national registries. We used Cox proportional hazards models to estimate hazard ratios with 95% confidence intervals (95% CIs), adjusted for potential confounders.

RESULTS

In all, 720 women developed EC. We found a statistically significant, positive dose-response relationship between LNYM and EC, with a 9.1% higher risk for each additional year of LNYM (P for trend < .001). Using the LNYM category ≥40 as a reference, the hazard ratios for LNYM <25, 25-29, 30-34, 35-39 were 0.17 (95% CI 0.22-0.27), 0.25 (95% CI 0.17-0.36), 0.43 (95% CI 0.32-0.58), and 0.68 (95% CI 0.51-0.92), respectively. The association between LNYM and EC was independent of incomplete pregnancies, menopausal hormone therapy, diabetes, and body mass index. When considering the population attributable fraction, 67% of EC was estimated to be attributable to LNYM ≥25 years.

CONCLUSIONS

Our study supports that increasing LNYM is an important and independent predictor of EC risk.

Menopause and postmenopausal hormone therapy and risk of hearing loss

OBJECTIVE

Menopause may be a risk factor for hearing loss, and postmenopausal hormone therapy (HT) has been proposed to slow hearing decline; however, there are no large prospective studies. We prospectively examined the independent relations between menopause and postmenopausal HT and risk of self-reported hearing loss.

METHODS

Prospective cohort study among 80,972 women in the Nurses' Health Study II, baseline age 27 to 44 years, followed from 1991 to 2013. Baseline and updated information was obtained from detailed validated biennial questionnaires. Cox proportional-hazards regression models were used to examine independent associations between menopausal status and postmenopausal HT and risk of hearing loss.

RESULTS

After 1,410,928 person-years of follow-up, 18,558 cases of hearing loss were reported. There was no significant overall association between menopausal status, natural or surgical, and risk of hearing loss. Older age at natural menopause was associated with higher risk. The multivariable-adjusted relative risk of hearing loss among women who underwent natural menopause at age 50+ years compared with those aged less than 50 years was 1.10 (95% confidence interval [CI] 1.03, 1.17). Among postmenopausal women, oral HT (estrogen therapy or estrogen plus progestogen therapy) was associated with higher risk of hearing loss, and longer duration of use was associated with higher risk (P trend < 0.001). Compared with women who never used HT, the multivariable-adjusted relative risk of hearing loss among women who used oral HT for 5 to 9.9 years was 1.15 (95% CI 1.06, 1.24) and for 10+ years was 1.21 (95% CI 1.07, 1.37).

CONCLUSIONS

Older age at menopause and longer duration of postmenopausal HT are associated with higher risk of hearing loss.

Current strategies in the diagnosis of endometrial cancer

PURPOSE

Endometrial cancer is the most common gynecological malignancy in developed countries. There are no uniform recommendations for endometrial cancer screening in the general population. Therefore, it is of paramount importance that the primary physician profoundly understands, and is familiar with the methods for prevention and early detection of endometrial cancer. The aim of this review is to provide the primary physician with a toolbox to reach these goals.

METHODS

We performed a systemic review to summarize the current strategies to diagnose and prevent endometrial cancer. Many published articles from the last years were identified and included.

RESULTS

A systematic review that summarizes the important subjects in the diagnosis and prevention of endometrial cancer.

CONCLUSION

Maintaining a high index of suspicion and obtaining endometrial biopsies from all suspected patients is the key for achieving a timely diagnosis.

Reproductive factors and incidence of endometrial cancer in U.S. black women

PURPOSE

Previous studies have shown that reproductive history is a strong determinant of endometrial cancer risk among white women. Less is known about how reproductive history affects endometrial cancer risk among black women, whose incidence and mortality differ from white women. We investigated the associations of age at menarche, parity, timing of births, and menopausal age with endometrial cancer in the Black Women's Health Study, a prospective cohort study.

METHODS

Every 2 years from 1995 to 2013, 47,555 participants with intact uteri at baseline in 1995 completed questionnaires on reproductive and medical history, and lifestyle factors. Self-reported cases of endometrial cancer were confirmed by medical record, cancer registry, or death certificate when available. Cox proportional hazards regression was used to estimate multivariable incidence rate ratios (IRR) and 95% confidence intervals (CI).

RESULTS

During 689,501 person-years of follow-up, we identified 300 incident cases of endometrial cancer. The strongest associations with endometrial cancer were found for early age at menarche (<11 vs. 12-13 years: IRR 1.82, 95% CI 1.31, 2.52), and later age at first birth (≥30 vs. <20 years: IRR 0.26, 95% CI 0.13, 0.50). Parous women were less likely than nulliparous women to develop endometrial cancer (IRR 0.77, 95% CI 0.57, 1.05), but there was little evidence of a dose-response relationship for number of births.

CONCLUSION

Associations between reproductive factors and endometrial cancer among black women were generally consistent with those in studies of white women.

Changing trends in reproductive/lifestyle factors in UK women: descriptive study within the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS)

OBJECTIVE

There has been considerable interest in the impact of reproductive factors on health but there are little data on how these have varied over time. We explore trends in reproductive/lifestyle factors of postmenopausal British women by analysing self-reported data from participants of the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS).

DESIGN

Prospective birth cohort analysis.

SETTING

Population cohort invited between 2001 and 2005 from age-sex registers of 27 Primary Care Trusts in England, Wales and Northern Ireland and recruited through 13 National Health Service Trusts.

PARTICIPANTS

202 638 postmenopausal women aged 50-74 years at randomisation to UKCTOCS between April 2001 and October 2005.

INTERVENTIONS

Women were stratified into the following six birth cohorts (1925-1929, 1930-1934, 1935-1939, 1940-1944, 1945-1949, 1950-1955) based on year of birth. Self-reported data on reproductive factors provided at recruitment were explored using tabular and graphical summaries to examine for differences between the birth cohorts.

OUTCOME MEASURES

Trends in mean age at menarche and menopause, use of oral contraceptives, change in family size, infertility treatments, tubal ligation and hysterectomy rates.

RESULTS

Women born between 1935 and 1955 made up 86% of the cohort. Median age at menarche decreased from 13.4 for women born between 1925 and 1929 to 12.8 for women born between 1950 and 1955. Increased use of the oral contraceptives, infertility treatments and smaller family size was observed in the younger birth cohorts. Tubal ligation rates increased for those born between 1925 and 1945, but this increase did not persist in subsequent cohorts. Hysterectomy rates (17-20%) did not change over time.

CONCLUSIONS

The trends seen in this large cohort are likely to reflect the reproductive history of the UK female postmenopausal population of similar age. Since these are risk factors for hormone-related cancers, these trends are important in understanding the changing incidence of these cancers.

TRIAL REGISTRATION NUMBER

International Standard Randomised Controlled Trial Number: 22488978.

Analysis of serum level of HE4 and CA125 considering selected risk factors among patients with endometrioid endometrial cancer

The aim of the study

To assess the difference of serum level of HE4 and CA125 among patients with endometrioid endometrial cancer, considering the presence or absence of selected risk factors.

Material and methods

A retrospective study of 46 patients, whose serum level of HE4 and CA125 level was documented, admitted to our Clinic because of endometrioid endometrial cancer. The statistical difference of both markers was analyzed considering certain risk factors.

Results

In the examined group of patients there was no significant statistical difference of HE4 and CA125 levels among patients with and without the following risk factors: older age, menopausal status, overweight and obesity, hypertension, diabetes, early menarche, and family history of certain cancers. Similar results were obtained within the subgroup of patients with stage I endometrial cancer. Both HE4 and CA125 were significantly higher in premenopausal patients than in those after menopause in the more advanced stages of the disease. The same results were obtained within group of patients with advanced histological grading G2 and G3. In this group, higher levels of CA125 were observed among patients without hypertension. Among patients with histological grade G1 the serum level of HE4 was higher in the group of patients older than 60 years than it was in younger patients.

Conclusions

In the examined group of patients serum levels of tumour markers may not be affected by the selected risk factors. Higher HE4 and CA125 levels among premenopausal patients may be an alarming sign of advanced stages and classes of histological grading.

Epidemiology of Endometrial Carcinoma: Etiologic Importance of Hormonal and Metabolic Influences

Endometrial carcinoma is the most common gynecologic cancer in developed nations, and the annual incidence is projected to increase, secondary to the high prevalence of obesity, a strong endometrial carcinoma risk factor. Although endometrial carcinomas are etiologically, biologically, and clinically diverse, hormonal and metabolic mechanisms are particularly strongly implicated in the pathogenesis of endometrioid carcinoma, the numerically predominant subtype. The centrality of hormonal and metabolic disturbances in the pathogenesis of endometrial carcinoma, combined with its slow development from well-characterized precursors in most cases, offers a substantial opportunity to reduce endometrial carcinoma mortality through early detection, lifestyle modification, and chemoprevention. In this chapter, we review the epidemiology of endometrial carcinoma, emphasizing theories that link risk factors for these tumors to hormonal and metabolic mechanisms. Future translational research opportunities related to prevention are discussed.

Joint Effect of Genotypic and Phenotypic Features of Reproductive Factors on Endometrial Cancer Risk

Prolonged estrogen exposure is believed to be the major cause of endometrial cancer. As possible markers of estrogen exposure, various menstrual and reproductive features, e.g., ages at menarche and menopause, are found to be associated with endometrial cancer risk. In order to assess their combined effects on endometrial cancer, we created the total number of menstrual cycles (TNMC) that a woman experienced during her life or up to the time of study and two genetic risk scores, GRS1 for age at menarche and GRS2 for age at menopause. Comparing 482 endometrial cancer patients with 571 population controls, we found TNMC was associated with endometrial cancer risk and that the association remained statistically significant after adjustment for obesity and other potential confounders. Risk increased by about 2.5% for every additional 10 menstrual-cycles. The study also showed that high GRS1 was associated with increased risk. This relationship, however, was attenuated after adjustment for obesity. Our study further indicated women with high TNMC and GRS1 had twice the risk of endometrial cancer compared to those low in both indices. Our results provided additional support to the involvement of estrogen exposure in endometrial cancer risk with regard to genetic background and lifestyle features.

Age at menarche and endometrial cancer risk: a dose-response meta-analysis of prospective studies

Evidence between age at menarche and endometrial cancer risk have been controversial. Therefore, we conducted a meta-analysis of prospective studies to analyze the aforementioned association. Relevant studies were identified by searching PubMed and EMBASE databases until the end of June 2015. A random-effects model was used to estimate summary relative risks (RRs) and 95% confidence intervals (CIs) for associations between menarcheal age and endometrial cancer risk. Our meta-analysis included eight prospective studies involving 4553 subjects with endometrial cancer. The summarized RRs of endometrial cancer for menarcheal age were 0.68 (95%CI = 0.58-0.81, I(2) = 41.9%, P = 0.099, n = 8) when comparing women with oldest category of menarcheal age with women with youngest category of menarcheal age. Notably, there was an 4% reduction in risk for per 2 years delay in menarcheal age (summarized RR = 0.96; 95%CI = 0.94-0.98, I(2) = 45.7%, P = 0.101, n = 6). Additionally, significant inverse associations were consistent within all stratified analyses. There was no evidence of publication bias or significant heterogeneity between subgroups detected by meta-regression analyses. Our findings support the hypothesis that late menarcheal age is inversely associated with endometrial cancer risk. Further larger prospective or pooled studies are warranted to fully adjust for potential confounders and distinguish whether the associations differ by histological subtypes of endometrial cancer.

Risk factors for endometrial cancer among women with a BRCA1 or BRCA2 mutation: a case control study

BRCA mutation carriers may use tamoxifen for breast cancer prevention or treatment. Hormone replacement therapy is often prescribed after surgical menopause and oral contraceptives are recommended for ovarian cancer prevention. The objective of this study was to assess the impact of these medications and other risk factors on endometrial cancer risk in BRCA carriers. Women with a BRCA1 or BRCA2 mutation were identified from a registry of mutation carriers. Cases were 83 women who had a diagnosis of endometrial cancer. Controls were 1027 matched women who did not develop endometrial cancer and who had an intact uterus. All women completed a baseline questionnaire, which included questions about ages at menarche and menopause, oral contraceptive use, hormone replacement therapy use, hysterectomy, oophorectomy, breast cancer history and tamoxifen use. We estimated the odds ratio associated with each risk factor in a multivariate analysis. No differences were found between cases and controls in terms of age at menarche, BMI, smoking, or oral contraceptive use. In a multivariate analysis, for women taking estrogen-only hormone replacement therapy, the odds ratio was 0.23 (95% CI 0.03-1.78, p = 0.16), and for women taking progesterone-only hormone replacement therapy the odds ratio was 6.91 (95% CI 0.99-98.1, p = 0.05). The adjusted odds ratio for endometrial cancer associated with a history of tamoxifen use was 3.50 (95% CI 1.51-8.10, p = 0.003). The observed increased risk of endometrial cancer associated with progesterone-only therapy merits further study.

Ovulation Prevalence in Women with Spontaneous Normal-Length Menstrual Cycles - A Population-Based Cohort from HUNT3, Norway

BACKGROUND

Ovulatory menstrual cycles are essential for women's fertility and needed to prevent bone loss. There is a medical/cultural expectation that clinically normal menstrual cycles are inevitably ovulatory. Currently within the general population it is unknown the proportion of regular, normal-length menstrual cycles that are ovulatory. Thus, the objective of this study was to determine the population point prevalence of ovulation in premenopausal, normally menstruating women. The null hypothesis was that such cycles are ovulatory.

METHODS

This is a single-cycle, cross-sectional, population-based study-a sub-study of the HUNT3 health study in the semi-rural county (Nord Trøndelag) in mid-Norway. Participants included >3,700 spontaneously (no hormonal contraception) menstruating women, primarily Caucasian, ages 20-49.9 from that county. Participation rate was 51.9%. All reported the date previous flow started. A single, random serum progesterone level was considered ovulatory if ≥9.54 nmol/L on cycle days 14 to -3 days before usual cycle length (CL).

RESULTS

Ovulation was assessed in 3,168 women mean age 41.7 (interquartile range, [IQR] 36.8 to 45.5), cycle length 28 days (d) (IQR 28 to 28) and body mass index (BMI) 26.3 kg/m2 (95% CI 26.1 to 26.4). Parity was 95.6%, 30% smoked, 61.3% exercised regularly and 18% were obese. 1,545 women with a serum progesterone level on cycle days 14 to -3 were presumed to be in the luteal phase. Of these, 63.3% of women had an ovulatory cycle (n = 978) and 37% (n = 567) were anovulatory. Women with/ without ovulation did not differ in age, BMI, cycle day, menarche age, cigarette use, physical activity, % obesity or self-reported health. There were minimal differences in parity (96.7% vs. 94.5%, P = 0.04) and major differences in progesterone level (24.5 vs. 3.8 nmol/L, P = 0.001).

CONCLUSION

Anovulation in a random population occurs in over a third of clinically normal menstrual cycles.

Female Hormonal Factors and the Risk of Endometrial Cancer in Lynch Syndrome

IMPORTANCE

Apart from hysterectomy, there is no consensus recommendation for reducing endometrial cancer risk for women with a mismatch repair gene mutation (Lynch syndrome).

OBJECTIVE

To investigate the association between hormonal factors and endometrial cancer risk in Lynch syndrome.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort study included 1128 women with a mismatch repair gene mutation identified from the Colon Cancer Family Registry. Data were analyzed with a weighted cohort approach. Participants were recruited between 1997 and 2012 from centers across the United States, Australia, Canada, and New Zealand.

EXPOSURES

Age at menarche, first and last live birth, and menopause; number of live births; hormonal contraceptive use; and postmenopausal hormone use.

MAIN OUTCOMES AND MEASURES

Self-reported diagnosis of endometrial cancer.

RESULTS

Endometrial cancer was diagnosed in 133 women (incidence rate per 100 person-years, 0.29; 95% CI, 0.24 to 0.34). Endometrial cancer was diagnosed in 11% (n = 70) of women with age at menarche greater than or equal to 13 years compared with 12.6% (n = 57) of women with age at menarche less than 13 years (incidence rate per 100 person-years, 0.27 vs 0.31; rate difference, -0.04 [95% CI, -0.15 to 0.05]; hazard ratio per year, 0.85 [95% CI, 0.73 to 0.99]; P = .04). Endometrial cancer was diagnosed in 10.8% (n = 88) of parous women compared with 14.4% (n = 40) of nulliparous women (incidence rate per 100 person-years, 0.25 vs 0.43; rate difference, -0.18 [95% CI, -0.32 to -0.04]; hazard ratio, 0.21 [95% CI, 0.10 to 0.42]; P < .001). Endometrial cancer was diagnosed in 8.7% (n = 70) of women who used hormonal contraceptives greater than or equal to 1 year compared with 19.2% (n = 57) of women who used contraceptives less than 1 year (incidence rate per 100 person-years, 0.22 vs 0.45; rate difference, -0.23 [95% CI, -0.36 to -0.11]; hazard ratio, 0.39 [95% CI, 0.23 to 0.64]; P < .001). There was no statistically significant association between endometrial cancer and age at first and last live birth, age at menopause, and postmenopausal hormone use.

CONCLUSIONS AND RELEVANCE

For women with a mismatch repair gene mutation, some endogenous and exogenous hormonal factors were associated with a lower risk of endometrial cancer. These directions and strengths of associations were similar to those for the general population. If replicated, these findings suggest that women with a mismatch repair gene mutation may be counseled like the general population in regard to hormonal influences on endometrial cancer risk.

Genetics of endometrial cancer

Women who report a history of endometrial cancer in a first-degree relative are at increased risk of endometrial cancer, with a hazard ratio of 1.5 to 2.0. Only a minority of patients with familial endometrial cancer have a recognized cancer syndrome. Lynch syndrome is the most common genetic syndrome associated with endometrial cancer and a marked increased risk of colon cancer. Cowden syndrome is a rare condition resulting from a mutation in the tumor suppressor gene phosphatase and tensin homolog. The risk for endometrial cancer is about five times higher in women with Cowden syndrome than in the general population. Recently, a novel germline mutation in the POLD1 gene that encodes the catalytic subunit of DNA polymerase δ was described in several families with multiple cases of endometrial cancer. This mutation is also associated with colorectal cancer. The association between BRCA1 mutations and endometrial cancer has been investigated in several studies; it appears that the risk of endometrial cancer is restricted to women with a history of tamoxifen exposure. In recent years, research has focused on genetic polymorphisms that are associated with endometrial cancer risk. Although many polymorphisms have been identified, their clinical significance is unclear and they have not been adapted for clinical practice.

Clinical and pathological characterization of endometrial cancer in young women: identification of a cohort without classical risk factors

OBJECTIVE

Endometrial cancer (EC) is the most common gynecologic malignancy with known risk factors including excess estrogen and hereditary syndromes. The objective of this study was to determine the proportion of young women with EC that could be attributed to these factors and if, as we suspected, there is a third population of young women in which neither factor is identifiable. We were interested in comparing clinicopathologic characteristics and outcomes across subgroups in order to better inform treatment recommendations.

METHODS

We performed a retrospective chart review of women age 15-49 diagnosed with EC or complex atypical hyperplasia. Demographic, clinicopathologic, treatment, fertility, and outcome parameters were analyzed.

RESULTS

Of 719 women identified, 327 were fully evaluable. 57.5% fit the "High Estrogen" risk criteria. 8.25% met criteria for suspected Lynch syndrome. 34.25% classified as "Neither" had no classical risk factors identified. There were no statistical differences in age, gravidity, tumor grade, treatment selection and response to hormonal therapy. Age of menarche, stage, histology, and synchronous ovarian cancer differed significantly. Prevalence of synchronous ovarian cancer was 21.0% of "Neither", 23.1% of "Lynch", and 6.6% of "High Estrogen". For women who attempted pregnancy, 2/27 of "High Estrogen", 0/3 of "Lynch", and 2/16 of "Neither" achieved a live birth.

CONCLUSIONS

This study confirmed that a third population of young women with EC exist that lack classical risk factors and have distinct clinicopathologic parameters. No difference in success of conservative treatment or live births was noted in the small cohort in whom this treatment approach was attempted.

Reproductive Factors and the Risk of Endometrial Cancer

Abstract

Endometrial cancer is the most common malignancy of women in developed countries, and its incidence is 10 times higher than in developing countries. Endometrial cancer is most common in the sixth and the seventh decades of life; thus, postmenopausal women have a higher risk of developing the disease compared with premenopausal women. The increased incidence and prevalence of endometrial cancer can be explained by the increase in life expectancy, increased caloric intake, increased obesity rates, and other changes in lifestyle and reproductive factors. Among the reproductive factors, the risk of endometrial cancer is positively correlated with a younger age at menarche and late age at menopause, infertility, null parity, age of the first child, and long-term use of unopposed estrogens for hormone replacement therapy. Protection against endometrial cancer has been detected with increase parity, the use of combined oral contraceptives, and increased age of women at last delivery. The relationship between endometrial cancer risk and miscarriage, abortion, ovulation induction drugs and in vitro fertilization is still controversial.

Genome-wide association studies of age at menarche and age at natural menopause

Genome-wide association studies (GWAS) have been successful in uncovering genetic determinants of age at menarche and age at natural menopause. To date, more than 30 novel genetic loci have been identified in GWAS for age at menarche and 17 for age at natural menopause. These findings have stimulated a plethora of follow-up studies particularly with respect to the functional characterization of these novel loci and how these results can be translated into risk prediction. However, the genetic loci identified so far account for only a small fraction of the overall heritability. This review provides an overview of the current state of our knowledge of the genetic basis of menarche and menopause timing. It emphasizes recent GWAS results and outlines strategies for discovering the missing heritability and strategies to further our understanding of the underlying molecular mechanisms of the observed genetic associations.

Race/ethnic disparities in reproductive age: an examination of ovarian reserve estimates across four race/ethnic groups of healthy, regularly cycling women

OBJECTIVE

To determine whether reproductive age, as indexed by a validated marker of ovarian reserve (antimüllerian hormone [AMH]), varies among women of different race/ethnic backgrounds.

DESIGN

Cross-sectional study.

SETTING

Community-based sample.

PATIENT(S)

Multiethnic sample of 947 (277 white, 237 African American, 220 Latina, and 213 Chinese) healthy and regularly cycling premenopausal women, ages 25-45.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

AMH level.

RESULT(S)

A multivariate model was fit examining race/ethnicity, covariates, nonlinear terms for age (age(2), age(3)), and body mass index (BMI(2), BMI(3)), and two-way interactions between race/ethnicity and each of the other predictor variables in relation to AMH. After backward elimination, significant effects included race/ethnicity (F = 8.45), age (F = 349.94), race/ethnicity-by-linear age interaction (F = 4.67), age(2) (F = 31.61), and BMI (F = 10.69). Inspection of the significant race/ethnicity-by-linear age interaction showed AMH levels were consistently lower among Latina women compared with white women across all ages, whereas AMH levels were lower among African American and Chinese women compared with the white women at younger and middle ages, respectively. The AMH levels were higher among African American compared with Latina and Chinese women at older ages.

CONCLUSION(S)

Although the results must be considered preliminary, the findings are twofold: African American women may have lower AMH levels at younger ages but experience less of a reduction in AMH with advancing age, and Latina and Chinese women compared with white women may have lower AMH levels, marking a lower ovarian reserve and a possibly increased risk for earlier menopause.

Polymorphisms in inflammation pathway genes and endometrial cancer risk

BACKGROUND

Experimental and epidemiologic evidence have suggested that chronic inflammation may play a critical role in endometrial carcinogenesis.

METHODS

To investigate this hypothesis, a two-stage study was carried out to evaluate single-nucleotide polymorphisms (SNP) in inflammatory pathway genes in association with endometrial cancer risk. In stage I, 64 candidate pathway genes were identified and 4,542 directly genotyped or imputed SNPs were analyzed among 832 endometrial cancer cases and 2,049 controls, using data from the Shanghai Endometrial Cancer Genetics Study. Linkage disequilibrium of stage I SNPs significantly associated with endometrial cancer (P < 0.05) indicated that the majority of associations could be linked to one of 24 distinct loci. One SNP from each of the 24 loci was then selected for follow-up genotyping. Of these, 21 SNPs were successfully designed and genotyped in stage II, which consisted of 10 additional studies including 6,604 endometrial cancer cases and 8,511 controls.

RESULTS

Five of the 21 SNPs had significant allelic odds ratios (ORs) and 95% confidence intervals (CI) as follows: FABP1, 0.92 (0.85-0.99); CXCL3, 1.16 (1.05-1.29); IL6, 1.08 (1.00-1.17); MSR1, 0.90 (0.82-0.98); and MMP9, 0.91 (0.87-0.97). Two of these polymorphisms were independently significant in the replication sample (rs352038 in CXCL3 and rs3918249 in MMP9). The association for the MMP9 polymorphism remained significant after Bonferroni correction and showed a significant association with endometrial cancer in both Asian- and European-ancestry samples.

CONCLUSIONS

These findings lend support to the hypothesis that genetic polymorphisms in genes involved in the inflammatory pathway may contribute to genetic susceptibility to endometrial cancer. Impact statement: This study adds to the growing evidence that inflammation plays an important role in endometrial carcinogenesis.

Non-contraceptive benefits of oral hormonal contraceptives

It is becoming evident that oral hormonal contraceptives-besides being well established contraceptives-seem to become important medications for many functional or organic disturbances. So far, clinical effectiveness has been shown for treatment as well as prevention of menstrual bleeding disorders and menstrual-related pain symptoms. Also this is true for premenstrual syndrome (PMS) and premenstrual disphoric disorder (PMDD). Particular oral contraceptives (OCs) containing anti-androgenic progestogens were shown to be effective medications for treatment of androgenisation symptoms (seborrhea, acne, hirsutism, alopecia). Through perfect suppression of the hypothalamic-pituitary-ovarian axis OCs have proven to be effective in elimination of persistent follicular cysts. Endometriosis/adenomyosis related pain symptoms are well handled similar to other drugs like Gonadotropine Releasing Hormone agonists but are less expensive, with less side effects, and possibility to be used for longer periods of time. This is also true for myoma. Pelvic inflammatory disease, rheumatoid arthritis, menstrual migraine, and onset of multiple sclerosis are prevented or delayed. Bone density is preserved and asthma symptoms improved. Endometrial hyperplasia and benign breast disease can be controlled. There is definitely a significant impact on risk reduction regarding endometrial, ovarian, and colon cancers. In conclusion, it needs to be recognized that oral combined hormonal contraceptives (estrogen/ progestogen combination) are - besides being reliable forms of contraception - are cost-effective medications for many medical disorders in women. Therefore, these contraceptives drugs are important for female and global health and should be used in clinical practice.

Capacity of endometrial thickness measurement to diagnose endometrial carcinoma in asymptomatic postmenopausal women: a systematic review and meta-analysis

OBJECTIVES

Measurement of endometrial thickness is an important tool in the assessment of women with postmenopausal bleeding, but the role of endometrial thickness measurement by ultrasound in asymptomatic women is unclear. The aims of this study were to determine: (1) the normal endometrial thickness measured by ultrasonography, (2) the prevalence of serious endometrial pathology and (3) the sensitivity and specificity of endometrial thickness measurement by transvaginal ultrasonography (TVS) for diagnosing premalignant and malignant endometrial disease in asymptomatic postmenopausal women.

METHODS

A MEDLINE and EMBASE search (from inception to January 2011) was performed. Articles reporting on endometrial thickness measurement in the diagnosis of endometrial carcinoma and atypical hyperplasia in asymptomatic postmenopausal women not using hormone replacement therapy (HRT) were selected. Endometrial thickness and the prevalence of endometrial (pre)malignancies were recorded. If possible, 2 × 2 tables were extracted.

RESULTS

Thirty-two studies reporting on 11100 women were included. The estimated mean endometrial thickness was 2.9 mm (95% CI, 2.6-3.3 mm). The pooled estimated prevalences of endometrial carcinoma and atypical endometrial hyperplasia were 0.62% (95% CI, 0.42-0.82%) and 0.59% (95% CI, 0.22-0.96%), respectively. Summary estimates for sensitivity and specificity of TVS endometrial thickness measurement in the prediction of endometrial carcinoma were 0.83 (95% CI, 0.19-1.00) and 0.72 (95% CI, 0.23-0.95) for a 5-mm cut-off and 0.33 (95% CI, 0.04-0.85) and 0.94 (95% CI, 0.92-0.96) for a 6-mm cut-off.

CONCLUSIONS

The results from this systematic review do not justify the use of endometrial thickness as a screening test for endometrial carcinoma and atypical endometrial hyperplasia in asymptomatic postmenopausal women not using HRT.

Prediction models in women with postmenopausal bleeding: a systematic review

Postmenopausal bleeding is associated with an elevated risk of having endometrial cancer. The aim of this review is to give an overview of existing prediction models on endometrial cancer in women with postmenopausal bleeding. In a systematic search of the literature, we identified nine prognostic studies, of which we assessed the quality, the different phases of development and their performance. From these data, we identified the most important predictor variables. None of the detected models completed external validation or impact analysis. Models including power Doppler showed best performance in internal validation, but Doppler in general gynecological practice is not easily accessible. We can conclude that we have indications that the first step in the approach of women with postmenopausal bleeding should be to distinguish between women with low risk versus high risk of having endometrial carcinoma and the next step would be to refer patients for further (invasive) testing.

Age at last birth in relation to risk of endometrial cancer: pooled analysis in the epidemiology of endometrial cancer consortium

Childbearing at an older age has been associated with a lower risk of endometrial cancer, but whether the association is independent of the number of births or other factors remains unclear. Individual-level data from 4 cohort and 13 case-control studies in the Epidemiology of Endometrial Cancer Consortium were pooled. A total of 8,671 cases of endometrial cancer and 16,562 controls were included in the analysis. After adjustment for known risk factors, endometrial cancer risk declined with increasing age at last birth (P(trend) < 0.0001). The pooled odds ratio per 5-year increase in age at last birth was 0.87 (95% confidence interval: 0.85, 0.90). Women who last gave birth at 40 years of age or older had a 44% decreased risk compared with women who had their last birth under the age of 25 years (95% confidence interval: 47, 66). The protective association was similar across the different age-at-diagnosis groups and for the 2 major tumor histologic subtypes (type I and type II). No effect modification was observed by body mass index, parity, or exogenous hormone use. In this large pooled analysis, late age at last birth was independently associated with a reduced risk of endometrial cancer, and the reduced risk persisted for many years.