Risk of cancer in women receiving hormone replacement therapy

Supportive care of female hormones in brain health: what and how?

Female hormones, functioning as neuroactive steroids, are utilized beyond menopausal hormone therapy. The rapid onset of allopregnanolone analogs, such as brexanolone and zuranolone, in treating depression, and the effectiveness of megestrol acetate in addressing appetite and weight gain, prompted the Food and Drug Administration to authorize the use of progesterone for treating postpartum depression and cancer-related cachexia. Progesterone has also been found to alleviate neuropathic pain in animal studies. These off-label applications offer a promising option for patients with advanced cancer who often experience various mood disorders such as depression, persistent pain, social isolation, and physical complications like cachexia. These patients have shown low tolerance to opioids and mood-regulating medications. However, the potential risks and uncertainties associated with hormone therapy treatment modalities can be daunting for both patients and medical professionals. This review aims to offer a comprehensive understanding of the non-reproductive functions and mechanisms of female hormones in brain health.

The risk of ovarian cancer in hormone replacement therapy users: a systematic review and meta-analysis

Background

With the increasing use of hormone replacement therapy (HRT), there is a need to understand its impact on the occurrence of female malignant tumors. This systematic review and meta-analysis aimed to assess the risk of ovarian cancer associated with HRT and its related risk factors.

Methods

PUBMED, OVID, Embase, Cochrane, and Web of Science were searched from 1980 to April 2022 to identify studies on the risk of ovarian cancer and hormone replacement therapy. The random-effects model was used to estimate the pooled risk of HRT in ovarian cancer, both in cohort studies and case-control studies. Additionally, the analysis examined the outcomes associated with different types of estrogen plus progesterone regimens. Meta-regression and sensitive analysis were performed to evaluate the heterogeneity.

Results

21 cohort studies (involving 15,313 cases and 4,564,785 participants) and 30 case-control studies (including 18,738 cases and 57,747 controls) were analyzed. The pooled risks of ovarian cancer for HRT users were 1.20 (95% confidence interval [CI] 1.01-1.44) from cohort studies and 1.13 (95%CI 1.04-1.22) from case-control studies. However, after restricting the study period to recent decades, the significant results indicating a higher risk disappeared in cohort studies conducted after 2010 and in case-control studies conducted after 2006. Furthermore, the continuous use of estrogen-progesterone replacement therapy (EPRT) was associated with a risk comparable to that of sequential use. Subgroup analysis showed that both estrogen replacement treatment (ERT) and EPRT had minor risks; The risk further increased with prolonged exposure time, particularly for durations exceeding 10 years. Additionally, serous ovarian cancer appeared to be more susceptible than other pathological types.

Conclusion

The risk of ovarian cancer associated with HRT has been decreasing over time. However, ERT may increase this risk, particularly when used for an extended period. It is recommended that long-time users consider continuous EPRT as a safer alternative.

Systematic review registration

www.crd.york.ac.uk/prospero/, identifier CRD42022321279.

25-hydroxycholesterol promotes proliferation and metastasis of lung adenocarcinoma cells by regulating ERβ/TNFRSF17 axis

Lung adenocarcinoma is the main type of lung cancer in women. Our previous findings have evidenced that 25-hydroxycholesterol (25-HC) promotes migration and invasion of lung adenocarcinoma cells (LAC), during which LXR as a 25-HC receptor plays an important role. Estrogen receptor beta (ERβ) is a receptor of 27-hydroxycholesterol that is structurally analogous to 25-HC, but its role in the functional actions of 25-HC remained largely unknown. In this study, we demonstrated that 25-HC treatment triggered ERβ expression in LAC. Knockdown of ERβ inhibited 25-HC-mediated proliferation, migration and invasion, and reduced 25-HC-induced LAC metastasis in vivo. Further investigation revealed that ERβ knockdown restrained the expression of TNFRSF17 (BCMA). In vivo experiments also confirmed that ERβ knockdown blocked 25-HC-induced TNFRSF17 expression. TNFRSF17 knockdown also restrained 25-HC-induced proliferation, migration and invasion. Bioinformatic analysis showed that the levels of ERβ and TNFRSF17 were elevated in lung adenocarcinoma, and were closely related to tumor stages and nodal metastasis status. These results suggested that 25-HC promoted the proliferation and metastasis of LAC by regulating ERβ/TNFRSF17 axis.

Association with menopausal hormone therapy and asymptomatic gallstones in US women in the third National Health and Nutrition Examination Study

15% of US adults have gallstones, most of which are clinically "silent". Several studies show that menopausal hormone therapy (MHT) increases symptomatic gallstones and cholecystectomy risk. MHT use may be contraindicated in women with gallstones and population studies may be biased by "confounding by contraindication" while the true association between MHT and gallstones remains underestimated. We sought to examine whether MHT use was associated with asymptomatic gallstones using instrumental variable (IV) analysis to account for confounding by contraindication. We used 2018 postmenopausal women from the Third National Health and Nutrition Examination Survey to estimate associations of MHT use with asymptomatic gallstones. A traditional logistic regression analysis was compared to instrumental variable (IV) analysis to account for confounding by contraindication. 12% of women with asymptomatic gallstones and 25% of women without gallstones were current MHT users (P < 0.001). The traditional analysis suggested a decreased odds of asymptomatic gallstones in current versus never users (OR 0.58, 95% CI 0.37, 0.89), but increased odds (OR 1.51, 95% CI 0.44, 5.16) in the IV analysis. The traditional analysis consistently underestimated the odds of asymptomatic gallstones with MHT use compared to the IV analysis. Accounting for confounding by contraindication, we found a suggestive, though imprecise, positive association between MHT use and asymptomatic gallstones among postmenopausal women. Failure to consider contraindication can produce incorrect results.

Sex Differences in Lung Cancer

Sex disparities in the incidence and mortality of lung cancer have been observed since cancer statistics have been recorded. Social and economic differences contribute to sex disparities in lung cancer incidence and mortality, but evidence suggests that there are also underlying biological differences that contribute to the disparity. This review summarizes biological differences which could contribute to the sex disparity. Sex hormones and other biologically active molecules, tumor cell genetic differences, and differences in the immune system and its response to lung cancer are highlighted. How some of these differences contribute to disparities in the response to therapies, including cytotoxic, targeted, and immuno-therapies, is also discussed. We end the study with a discussion of our perceived future directions to identify the key biological differences which could contribute to sex disparities in lung cancer and how these differences could be therapeutically leveraged to personalize lung cancer treatment to the individual sexes.

The association between hormone therapy and the risk of lung cancer in postmenopausal women: a 16-year nationwide population-based study

OBJECTIVE

Although an association between hormone therapy (HT) and the risk of developing lung cancer has been reported, the results on the topic are inconsistent. Our study objective was to investigate whether postmenopausal women who undergo HT exhibit a risk of developing lung cancer.

METHODS

In this matched cohort study, we obtained the data of 38,104 postmenopausal women older than 45 years who were treated using HT between 2000 and 2015 from Taiwan's National Health Insurance Research Database, and 152,416 matched participants who were not treated using HT were enrolled as controls at a 1:4 ratio.

RESULTS

We used a Cox proportional hazards regression model to identify the risk of developing lung cancer during 16 years of follow-up, and the results indicate no significant difference in the proportion of postmenopausal women treated using HT ( P = 0.129) who developed lung cancer and that of those not treated using HT (0.866% [330 of 38,104] vs 0.950% [1,449 of 152,416]). After adjustment for age and other variables, the adjusted hazard ratio was 0.886 (95% CI, 0.666-1.305, P = 0.433), indicating no association between HT and lung cancer development in postmenopausal women. In a subgroup analysis, the risk of lung cancer was significantly lower in the women who were treated using HT when the HT cumulative dosage was ≥401 mg or when the therapy duration was ≥5 years compared with in those not treated using HT; the adjusted hazard ratios were 0.633 (95% CI, 0.475-0.930; P < 0.001) and 0.532 (95% CI, 0.330-0.934; P < 0.001), respectively, after adjustment.

CONCLUSIONS

Our results indicate that HT is not associated with the risk of lung cancer development in postmenopausal women; furthermore, a higher cumulative dosage and the long-term effects of HT reduce the risk of developing lung cancer.

Exogenous Hormone Factors in Relation to the Risk of Malignant Melanoma in Women: A Systematic Review and Meta-Analysis

The influence of exogenous female hormones on the risk of developing malignant melanoma in women remains controversial. The aim of our review and meta-analysis is to summarize the evidence and derive a more accurate estimation of the association between oral contraceptives (OCs) or menopausal hormone therapy (MHT) and the risk of developing malignant melanoma in women. PubMed, Web of Science, and Scopus database were searched for studies published up until October 2021. The PRISMA statement and MOOSE guidelines were followed. Studies were pooled using a random effects model. Heterogeneity was explored with the chi-square-based Cochran’s Q statistic and the I2 statistic. Publication bias was assessed with Begg’s test and Egger’s test. Forty-six studies met the eligibility criteria. The pooled analysis (26 studies) on OC use and the risk of developing cutaneous malignant melanoma (CMM) showed no significant association, but demonstrated significant association for cohort studies (OR 1.08, 95% CI 1.01–1.16; I2 = 0.00%, p = 0.544). The pooled analysis (16 studies) showed a significantly increased risk of CMM in association with MHT (OR 1.15, 95% CI 1.08–1.23; I2 = 25.32%, p = 0.169). Stratifying the results by study design showed that a significant increased risk of CMM was associated with MHT in the cohort studies (OR 1.12; 95% CI 1.04–1.19; I2 = 0%, p = 0.467). No significant publication bias could be detected. Further studies are needed to investigate the potential association with formulation, duration of use, and dosage of use, and to better understand the role of possible confounders.

Management of postmenopausal women: Collège National des Gynécologues et Obstétriciens Français (CNGOF) and Groupe d'Etude sur la Ménopause et le Vieillissement (GEMVi) Clinical Practice Guidelines

AIM

The aim of these recommendations is to set forth an individualized approach to the management of early postmenopausal women (i.e., within the first 10 years after natural menopause) covering all aspects of lifestyle and therapeutic management, with or without menopause hormone therapy (MHT).

MATERIALS AND METHODS

Literature review and consensus of French expert opinion. Recommendations were graded according to the HAS methodology and levels of evidence derived from the international literature, except when there was no good-quality evidence.

SUMMARY RECOMMENDATIONS

The beginning of menopause is an ideal time for each woman to evaluate her health status by assessing her bone, cardiovascular, and cancer-related risk factors that may be amplified by postmenopausal estrogen deficiency and by reviewing her lifestyle habits. Improving lifestyle, including nutrition and physical activity, and avoiding risk factors (notably smoking), should be recommended to all women. MHT remains the most effective treatment for vasomotor symptoms but it could be also recommended as first-line treatment for the prevention of osteoporosis in early postmenopausal women at low to moderate risk for fracture. The risks of MHT differ depending on its type, dose, duration of use, route of administration, timing of initiation, and whether a progestogen is used. There is reasonable evidence that using transdermal estradiol in association with micronized progesterone or dydrogesterone may limit both the venous thromboembolic risk associated with oral estrogens and the risk of breast cancer associated with synthetic progestins. Treatment should be individualized to each woman, by using the best available evidence to maximize benefits and minimize risks, with periodic reevaluation of its benefit-risk balance. For bothersome genitourinary syndrome of menopause (GSM) symptoms, vaginal treatment with lubricants and moisturizers is recommended as first-line treatment together with low-dose vaginal estrogen therapy, depending on the clinical course. No recommendation of an optimal duration of MHT can be made, but it must take into consideration the initial indication for MHT as well as each woman's benefit-risk balance. Management of gynecological side-effects of MHT is also examined. These recommendations are endorsed by the Groupe d'Etude sur la Ménopause et le Vieillissement hormonal (GEMVI) and the Collège National des Gynécologues-Obstétriciens Français (CNGOF).

Dietary fibre intake is associated with reduced risk of lung cancer: a Japan public health centre-based prospective study (JPHC)

BACKGROUND

Several epidemiological studies have been conducted to draw consistent conclusions regarding the effect of dietary fibre on lung diseases and lung cancer. However, the effect of dietary fibre on the incidence of lung cancer remains unclear in an Asian population.

METHODS

We investigated the association between the intake of total dietary fibre and dietary fibre from different food sources and lung cancer incidence in a Japan public health centre-based prospective study (JPHC). A total of 73 405 participants (33 012 men and 40 393 women) aged 45-74 years were eligible for our study. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

During a median follow-up of 18.0 years, 1546 (1042 men and 504 women) newly diagnosed cases of lung cancer were ascertained. In the multivariable models, total dietary fibre intake was inversely associated with lung cancer risk in men, the HRs Q5 vs Q1 (95% CI) were 0.77 (0.62 to 0.94), P-trend = 0.020. Dietary fibre intake from vegetables was protectively associated with lung cancer risk in men [HR Q5 vs Q1 (95% CI): 0.80 (0.64 to 0.99), P-trend = 0.053]. However, no such association was observed in women.

CONCLUSIONS

In men, a high intake of total dietary fibre may have preventive benefits for lung cancer incidence: dietary fibre intake from vegetables was associated with a lower incidence of lung cancer. However, similar associations did not appear in women. Further investigations are required to confirm the association between dietary fibre and lung cancer risk in women.

Menopausal hormone therapy and risk of biliary tract cancers

BACKGROUND AND AIMS

Gallbladder cancer (GBC) has a female predominance, whereas the other biliary tract cancers (BTCs) have a male predominance, suggesting that sex hormones may be involved in carcinogenesis. We sought to evaluate the association between menopausal hormone therapy (MHT) and the risk of BTC in women.

APPROACH AND RESULTS

This nested case-control study was conducted in the UK Clinical Practice Research Datalink. Cases diagnosed between 1990 and 2017 with incident primary cancers of the gallbladder (GBC), cholangiocarcinoma (CCA), ampulla of Vater (AVC), and mixed type were matched to 5 controls on birth year, diagnosis year, and years in the general practice using incidence density sampling. Conditional logistic regression was used to calculate ORs and 95% CIs for associations between MHT use and BTC type. The sample consisted of 1,682 BTC cases (483 GBC, 870 CCA, 105 AVC, and 224 mixed) and 8,419 matched controls with a mean age of 73 (SD, 11) years. Combined formulations (estrogen-progesterone) were associated with an increased GBC risk (OR, 1.97; 95% CI, 1.08, 3.59). Orally administered MHT was associated with an increased GBC risk (OR, 2.28; 95% CI, 1.24, 4.17). Estrogen-only formulations (OR, 0.59; 95% CI, 0.34, 0.93) and cream or suppository administrations (OR, 0.57; 95% CI, 0.34, 0.95) were associated with decreased CCA risk. The number of prescriptions, dose, duration of use, and time since last use were not associated with GBC or CCA risk. MHT use was not associated with risk of AVC or mixed cancer.

CONCLUSIONS

Combination MHT formulations and oral administrations were associated with increased GBC risk, whereas estrogen-only formulations were associated with a lower CCA risk. MHT formulation and administration should be carefully considered when prescribing.

Hormone Therapy in Menopause: Concepts, Controversies, and Approach to Treatment

Hormone therapy (HT) is an effective treatment for menopausal symptoms, including vasomotor symptoms and genitourinary syndrome of menopause. Randomized trials also demonstrate positive effects on bone health, and age-stratified analyses indicate more favorable effects on coronary heart disease and all-cause mortality in younger women (close proximity to menopause) than in women more than a decade past menopause. In the absence of contraindications or other major comorbidities, recently menopausal women with moderate or severe symptoms are appropriate candidates for HT. The Women's Health Initiative (WHI) hormone therapy trials-estrogen and progestin trial and the estrogen-alone trial-clarified the benefits and risks of HT, including how the results differed by age. A key lesson from the WHI trials, which was unfortunately lost in the posttrial cacophony, was that the risk:benefit ratio and safety profile of HT differed markedly by clinical characteristics of the participants, especially age, time since menopause, and comorbidity status. In the present review of the WHI and other recent HT trials, we aim to provide readers with an improved understanding of the importance of the timing of HT initiation, type and route of administration, and of patient-specific considerations that should be weighed when prescribing HT.

The emerging role of estrogen related receptorα in complications of non-small cell lung cancers

Approximately 85% of lung cancer cases are recognized as non-small cell lung cancer (NSCLC) with a perilous (13–17%) 5-year survival in Europe and the USA. Although tobacco smoking has consistently emerged as the leading cause of NSCLC complications, its consequences are distinctly manifest with respect to sex bias, due to differential gene and sex hormone expression. Estrogen related receptor α (ERRα), a member of the nuclear orphan receptor superfamily is normally expressed in the lungs, and activates various nuclear genes without binding to the ligands, such as estrogens. In NSCLC ERRα expression is significantly higher compared with healthy individuals. It is well established ERα and ERβ‚ have 93% and 60% identity in the DNA and ligand binding domains, respectively. ERα and ERRα have 69% (70% with ERRα-1) and 34% (35% with ERRα-1) identity, respectively; ERRα and ERRβ‚ have 92 and 61% identity, respectively. However, whether there is distinctive ERRα interaction with mammalian estrogens or concurrent involvement in non-ER signalling pathway activation is not known. Relevant to NSCLC, ERRα promotes proliferation, invasion and migration by silencing the tumor suppressor proteins p53 and pRB, and accelerates G₂-M transition during cell division. Epithelial to mesenchymal transition (EMT) and activation of Slug (an EMT associated transcription factor) are the prominent mechanisms by which ERRα activates NSCLC metastasis. Based on these observations, the present article focuses on the feasibility of antiERRα therapy alone and in combination with antiER as a therapeutic strategy for NSCLC complications.

Plausible Role of Estrogens in Pathogenesis, Progression and Therapy of Lung Cancer

Malignant neoplasms are among the most common diseases and are responsible for the majority of deaths in the developed world. In contrast to men, available data show a clear upward trend in the incidence of lung cancer in women, making it almost as prevalent as breast cancer. Women might be more susceptible to the carcinogenic effect of tobacco smoke than men. Furthermore, available data indicate a much more frequent mutation of the tumor suppressor gene-p53 in non-small cell lung cancer (NSCLC) female patients compared to males. Another important factor, however, might lie in the female sex hormones, whose mitogenic or carcinogenic effect is well known. Epidemiologic data show a correlation between hormone replacement therapy (HRT) or oral contraceptives (OCs), and increased mortality rates due to the increased incidence of malignant tumors, including lung cancer. Interestingly, two types of estrogen receptors have been detected in lung cancer cells: ERα and ERβ. The presence of ERα has been detected in tissues and non-small-cell lung carcinoma (NSCLC) cell lines. In contrast, overexpression of ERβ is a prognostic marker in NSCLC. Herein, we summarize the current knowledge on the role of estrogens in the etiopathogenesis of lung cancer, as well as biological, hormonal and genetic sex-related differences in this neoplasm.

Hormone replacement therapy and cervical cancer: a systematic review of the literature

Gynecological tumor treatment, including cervical cancer (CC) treatment, often leads to iatrogenic premature menopause. This highlights the critical importance of investigating indications for hormone replacement therapy (HRT), as most patients, thanks to the improvement in diagnosis and treatment, have to deal with the sequelae of their cancer treatments for many years. This systematic review aims to provide an overview of the current knowledge regarding the risks of HRT and CC. In particular, we aim to investigate whether the use of HRT can increase CC incidence, and evaluate its risk in CC survivors. A systematic review, in agreement with PRISMA guidelines, of the English literature present in PubMed and SCOPUS has been performed. A total of 2805 articles have been screened, of which 10 were considered eligible. Several studies reported a significantly reduced risk of developing cervical squamous cell carcinoma in postmenopausal women treated with HRT, while a weak increase in the incidence of adenocarcinoma has been shown. No evidence reports a harmful effect of HRT on CC oncological outcome, while several benefits, in terms of reduced metabolic risk and increased quality of life, have been described, thus concluding that HRT should be offered to young CC survivors for the management of early menopause.

Effects of Exogenous Hormones and Reproductive Factors on Female Melanoma: A Meta-Analysis

Epidemiological findings on the effects of hormones on melanoma risk have been inconsistent. We therefore conducted a meta-analysis to examine the relationship between exogenous hormonal and reproductive factors and the risk of melanoma in women. We performed a search of PubMed, Web of Science, and the China National Knowledge Infrastructure (CNKI) database through April 2020 for relevant studies. Based on heterogeneity, we performed the meta-analysis of the risk estimates using either fixed effect or random effect models. We identified 38 studies that met the analytical criteria, involving 3,571,910 participants. The results showed that long-term use of oral contraceptives (OC) may increase the risk of melanoma in women (≥5 years [pooled RR=1.18; 95% CI: 1.07-1.31; I²=0%] and ≥10 years [pooled RR=1.25; 95% CI: 1.06-1.48; I²=0%]). Women who first used OC 15-19 years previously were more likely to develop melanoma (pooled RR=1.52; 95% CI: 1.03-2.24; I²=0%), while the years since the last use and the age at first use were not associated with the development of melanoma in women. Hormone replacement therapy (HRT) increased the incidence of melanoma in women (pooled RR=1.12, 95% CI: 1.02-1.24; I²=50%) and was especially associated with an increased risk of superficial spreading melanoma (SSM) (pooled RR=1.26; 95% CI: 1.17-1.37; I²=0%), and estrogen and estradiol may be the main active agents that contribute to the increased risk of melanoma, but these results may be due to a combination of sun exposure factors. With regard to reproductive factors, decreased parity and being aged ≥20 years at first birth may be associated with an increased risk of melanoma in females, while menopausal status and age at menarche are not associated with the incidence of melanoma in females. Further large-scale prospective studies are necessary to reveal new pathophysiological mechanisms and new therapeutic targets for cutaneous melanoma.

Reproductive factors and lung cancer risk: a comprehensive systematic review and meta-analysis

BACKGROUND

A number of studies have investigated the association between reproductive factors and lung cancer risk, however findings are inconsistent. This meta-analysis aimed to evaluate the association between female reproductive factors and lung cancer risk.

METHODS

We conducted a comprehensive systematic search to identify relevant and eligible studies published before 18th December 2019. Inter-study heterogeneity was assessed using the Q test and I2 statistic. Based on the heterogeneity of each reproductive factor, fixed or random effects models were used to calculate the summary odds ratios (ORs) and 95% confidence intervals (CIs). Subgroup analyses by study design, lung cancer subtypes, smoking status, and ethnicity were also performed.

RESULTS

A total of 66 studies with 20 distinct reproductive factors were included in this meta-analysis. Comparing the highest and lowest categories (reference) of each reproductive factor, parity (OR = 0.83, 95% CI = 0.72-0.96), menstrual cycle length (OR = 0.79, 95% CI = 0.65-0.96), and age at first birth (OR = 0.85, 95% CI = 0.74-0.98), were significantly associated with a lower risk of overall lung cancer. On the contrary, non-natural menopause was significantly associated with higher lung cancer risk (OR = 1.52, 95% CI = 1.25-1.86). Among never-smokers, a significant negative association was found between parity and lung cancer risk. Both parity and non-natural menopause were statistically significant in case-control studies.

CONCLUSION

These results suggest that certain reproductive factors may be associated with lung cancer risk. Future studies should further validate the associations, and investigate the underlying mechanisms.

Postmenopausal exogenous hormone therapy and Melanoma risk in women: A systematic review and time-response meta-analysis

A favourable option to management symptoms during menopausal transition is menopausal hormone therapy (MHT) but relation among MHT and risk of melanoma is controversial. This study aims to identify, analyse and present the evidence surrounding post-menopausal exogenous hormone therapy and the risk for melanoma in women. A systematic searches of database was conducted in PubMed/MEDLINE, Scopus, and Cochrane without time, region, and language restrictions from inception to April 2020. The DerSimonian and Laird random-effects model was used to estimate combined risk ratio (RR) and 95% confidence intervals (CI). Subgroup analysis and time-response analysis was conducted based on the formulation of used hormone and length of hormone therapy. Combined results from fourteen studies that containing 19 arms with 1,164,077 participants which 4273 of them had melanoma cancer showed increase risk of melanoma in the hormone-treated versus control group 1.14 (95% CI 1.05-1.24, I2: 21%). The stronger and significant relationship between MHT and risk of melanoma was in participants who used oestrogen formulation (RR 1.32, 95% CI 1.17-1.49, I2 = 0%). Moreover, a significant non-linear time-response relation between MHT and melanoma was also in initial three years of MHT (Coef1 = 0.2423, p1 < 0.01). This study reveals a significant direct relationship between the MHT and risk of melanoma in postmenopausal women.

Important roles of estrogen receptor alpha in tumor progression and anti-estrogen therapy of pancreatic ductal adenocarcinoma

AIMS

The roles of estrogen receptors (ERs) and the efficacy of anti-estrogen (E2) therapies in pancreatic cancer stay controversial. The main objectives of this study were to investigate the potential roles of ERs in tumor progression and endocrine therapies.

MAIN METHODS

The ER expression status in PANC-1 and SW1990 pancreatic cancer cell lines was determined. SRB assay, colony formation assay and proliferation assay were used to investigate the responses of these cells to E2. ERα-selective agonist propylpyrazoletriol (PPT), ERβ-selective agonist diarylpropionitrile (DPN), ERα over-expressed SW1990 cells, ERα knock-out PANC-1 cells and patient-derived xenografts (PDX) were applied to investigate the potential roles of ERα in pancreatic cancer. The phosphorylation of ERα-related signaling molecules extracellular regulated protein kinases (ERK1/2) and protein kinase B (AKT) were investigated. The in vivo anti-tumor efficacy and safety of letrozole (LTZ) combined with leuprorelin acetate (LA) and gemcitabine (GEM) were also preliminarily studied.

KEY FINDINGS

PANC-1 cells expressed much more ERα than SW1990 cells, and ERβ level was with less diversity. Accordingly, the proliferation of PANC-1 rather than SW1990 cells could be stimulated by E2, and only PANC-1 could respond to LTZ endocrine therapy in female but not male mice. The phosphorylation of ERK1/2 but not AKT was altered by over-expressed or knocking out of ERα with or without the addition of E2 and LTZ. The combination therapy of LTZ and GEM showed acceptable efficacy and safety.

SIGNIFICANCE

This study showed the important roles of ERα in tumor progression and endocrine therapies of pancreatic cancer in women.

Dual targeting of SREBP2 and ERRα by carnosic acid suppresses RANKL-mediated osteoclastogenesis and prevents ovariectomy-induced bone loss

Osteoporosis develops because of impaired bone formation and/or excessive bone resorption. Several pharmacological treatment of osteoporosis has been developed; however, new treatments are still necessary. Cholesterol and estrogen receptor-related receptor alpha (ERRα) promote osteoclasts formation, survival, and cellular fusion and thus become high risk factors of osteoporosis. In this study, we identified that carnosic acid (CA) suppressed bone loss by dual-targeting of sterol regulatory element-binding protein 2 (SREBP2, a major regulator that regulates cholesterol synthesis) and ERRα. Mechanistically, CA reduced nuclear localization of mature SREBP2 and suppressed de novo biogenesis of cholesterol. CA subsequently decreased the interaction between ERRα and peroxisome proliferator-activated receptor gamma coactivator 1-beta (PGC1β), resulting in decreased the transcription activity of ERRα and its target genes expression. Meanwhile, CA directly bound to the ligand-binding domain of ERRα and significantly promoted its ubiquitination and proteasomal degradation. Subsequently, STUB1 was identified as the E3 ligase of ERRα. The lysine residues (K51 and K68) are essential for ubiquitination and proteasomal degradation of ERRα by CA. In conclusion, CA dually targets SREBP2 and ERRα, thus inhibits the RANKL-induced osteoclast formation and improves OVX-induced bone loss. CA may serve as a lead compound for pharmacological control of osteoporosis.

Transcriptome alterations in female Daphnia (Daphnia magna) exposed to 17β-estradiol

The molecular mechanism of evaluating 17β-estradiol (E₂)-induced toxicity in female Daphnia magna has not been determined. In this study, the transcriptome of D. magna was analyzed after exposure to three different concentrations (0, 10, and 100 ng L^-1) of E₂ at 3, 6, and 12 h. The results showed 351-17,221 significantly up-regulated and 505-10,282 significantly down-regulated genes (P < 0.05). Overall, the selected largest 10,282 (10 ng L^-1vs control at 12 h) down-regulated and 17,221 (100 vs 10 ng L^-1) up-regulated genes were identified; following annotation, pathways in cancer and RNA transport were found to be enriched according to the interaction network. Among all completed comparisons, KEGG pathways related to the immune system, cancer, disease infection, and active compound metabolism were identified by short time series expression miner analysis. A different set of genes fluctuated in a "U"-shaped pattern over time and at different concentrations of E₂, whereas some genes associated with disintoxication showed a reverse "U"-shaped response as E₂ administration was increased. These results suggest that E₂ exposure caused transcriptional changes in the immune system, disintoxication, disease prevention, and the protein degradation pathway.

Lung Cancer in Women: A Modern Epidemic

Lung cancer in women is a modern epidemic and a major health crisis. Cigarette smoking remains the most important risk factor for lung cancer, and unfortunately smoking rates are either stabilized or continue to increase among women. Women may not be more susceptible to the carcinogenic effects of tobacco, but the biology of lung cancer differs between the sexes. This paper summarizes the biological sex differences in lung cancer, including molecular abnormalities, growth factor receptors, hormonal influences, DNA repair capacity, as well as differences in the histology and treatment outcomes of lung cancer in women.

Hormone replacement therapy and lung cancer risk in women: a meta-analysis of cohort studies: Hormone replacement therapy and lung cancer risk

BACKGROUND

Discordant results about the causal relationship between hormone replacement therapy use (HRT) and lung cancer risk in women had been reported. We therefore conducted a meta-analysis of cohort studies to evaluate this association.

METHODS

The PubMed and Embase databases were searched. Fixed- or random-effects model was used to pool the study-specific relative risks (RRs) with corresponding 95% confidence intervals (CIs). Sensitivity analysis, publication bias, and subgroup analysis were performed.

RESULTS

A total of 13 cohort studies met the inclusion criteria. Combined results indicated that compared with nonusers, women with HRT use were at a decreased risk (RR: 0.95, 95% CI: 0.91-0.99, I = 30.8%, P for heterogeneity = .137). In subgroup analysis by geographic area, smoking statue, type of hormones, and histology type of lung cancer, no significant association between HRT use and lung cancer was observed in most subgroups except in those studies which reported risk estimates adjusted for age, body mass index, smoking, and other confounders (RR: 0.95, 95 CI: 0.91-0.99, I = 33.0%, P for heterogeneity = .214). Both Begg funnel plot and Egger test (P = .243) suggested no evidence for publication bias.

CONCLUSION

Our meta-analysis suggests ever use of HRT is associated with a decreased risk of lung cancer in women.

The influence of hormone replacement therapy on lung cancer incidence and mortality

OBJECTIVE

Data regarding the effects of hormone replacement therapy (HRT) on non-small cell lung cancer (NSCLC) are mixed. We hypothesized HRT would have a protective benefit with reduced NSCLC incidence among women in a large, prospective cohort.

METHODS

We used data from the multicenter randomized Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (1993-2001). Participants were women aged 50 to 74 years followed prospectively for up to 13 years for cancer screening. The influence of HRT on the primary outcome of NSCLC incidence and secondary outcomes of all-cause and disease-specific mortality were assessed with Kaplan-Meier analysis and Cox proportional hazard models adjusting for covariates.

RESULTS

In the overall cohort of 75,587 women, 1147 women developed NSCLC after a median follow-up of 11.5 years. HRT use was characterized as 49.4% current users, 17.0% former users, and 33.6% never users. Increased age, smoking, comorbidities, and family history were associated with increased risk of NSCLC. On multivariable analysis, current HRT use was associated with reduced risk of NSCLC compared with never users (hazard ratio, 0.80; 95% confidence interval, 0.70-0.93; P = .009). HRT or oral contraception use was not associated with significant differences in all-cause mortality or disease-specific mortality.

CONCLUSIONS

These data represent among the largest prospective cohorts suggesting HRT use may have a protective effect on the development of NSCLC among women; the physiological basis of this effect merits further study; however, the results may influence discussion surrounding HRT use in women.

Postmenopausal hormone use and cutaneous melanoma risk: A French prospective cohort study

Cutaneous melanoma has been suspected to be influenced by female hormones. Several studies reported a positive association between menopausal hormone therapy (MHT) use and melanoma risk; however, previous findings were conflicting. We sought to explore the associations between MHT use and melanoma risk in a prospective cohort of women in France, where a particularly wide variety of MHT formulations are available. E3N is a prospective cohort of 98,995 French women aged 40-65 years in 1990. MHT use was assessed through biennial self-administered questionnaires. We used Cox proportional hazards regression models adjusted for age and skin cancer risk factors. Over 1990-2008, 444 melanoma cases were ascertained among 75,523 postmenopausal women. Ever use of MHT was associated with a higher melanoma risk (hazard ratio (HR) = 1.35, 95% confidence intervals (CI) = 1.07-1.71). The association was strongest among past users (HR = 1.55, CI = 1.17-2.07, homogeneity for past vs. recent use: p = 0.11), and users of MHT containing norpregnane derivatives (HR = 1.59, CI = 1.11-2.27), although with no heterogeneity across types of MHT (p = 0.13). Among MHT users, the association was similar across durations of use. However, a higher risk was observed when treatment onset occurred shortly after menopause (<6 months: HR = 1.55, CI = 1.16-2.07 vs. ≥2 years). Associations between MHT use and melanoma risk were similar after adjustment for UV exposure, although MHT users were more likely to report sunscreen use than nonusers. Our data do not support a strong association between MHT use and melanoma risk. Further investigation is needed to explore potential effect modification by UV exposure on this relationship.

Sex steroid metabolism and actions in non-small cell lung carcinoma

Despite recent development in targeted therapies, lung cancer still remains the leading cause of cancer death. Therefore, a better understanding of its pathogenesis and progression could contribute to improving the eventual clinical outcome of the patients. Results of recently published several in vitro and clinical studies indicated the possible involvement of sex steroids in both development and progression of non-small cell lung carcinoma (NSCLC). Therefore we summarized the reported clinical relevant information of the sex steroids, their receptors and steroid metabolizing enzymes related to NSCLC in this mini-review. In addition, we also reviewed the potential "endocrine therapy", targeting sex steroid actions and/or metabolism in NSCLC patients.

Low‑frequency pulsed electromagnetic field inhibits RANKL‑induced osteoclastic differentiation in RAW264.7 cells by scavenging reactive oxygen species

Bone homeostasis is a dynamic balance maintained by bone formation and resorption. An increase in the number and activity of osteoclasts leads to excessive bone resorption, which in turn results in bone disease, including osteoporosis. Therefore, inhibiting the differentiation and activity of osteoclasts is important for maintaining bone mass. Several studies have revealed that the use of a low-frequency pulsed electromagnetic field (PEMF) is an effective method to treat osteoporosis. However, its exact mechanism remains to be fully clarified. Therefore, the present study was designed to examine the effects that PEMF exerts on receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis and intracellular reactive oxygen species (ROS) production in RAW264.7 cells. The viability of cells was determined using a Cell Counting Kit-8 assay, and gene and protein expression were investigated via reverse transcription-quantitative polymerase chain reaction and western blot analyses. Furthermore, microscopy was performed to detect the levels of intracellular ROS and tartrate-resistant acid phosphatase (TRAP). Following the culture of RAW264.7 cells with RANKL (50 ng/ml) for 4 days (3 h/day) under PEMF (75 Hz, 1 mt) exposure, it was observed that PEMF had an inhibitory effect on RANKL-induced osteoclastic differentiation. Multinucleated osteoclast formation, the activity of TRAP and the expression of osteoclastogenesis-associated genes, including cathepsin K, nuclear factor of activated T cells cytoplasmic 1 and TRAP, were significantly reduced by PEMF. Furthermore, PEMF effectively decreased the generation of intracellular ROS during osteoclastic differentiation. In addition, the results demonstrated that ROS are the key factor in osteoclast differentiation and formation. Reducing intracellular ROS with diphenylene-iodonium chloride significantly inhibited RANKL-induced osteoclast differentiation. Taken together, the results of the present study demonstrated that PEMF may inhibit RANKL-induced osteoclastogenesis by scavenging intracellular ROS. These results may provide the groundwork for future PEMF clinical applications in osteoclast-associated bone disease.

Menopausal hormone therapy and biliary tract cancer: a population-based matched cohort study in Sweden

BACKGROUND

This study tested the hypothesis that contemporary menopausal hormonal therapy (MHT) increases the risk of biliary tract cancer. The risk of cancer of the biliary tract (gallbladder and extra-hepatic bile ducts) may be increased following estrogen exposure.

MATERIAL AND METHODS

This was a nationwide population-based matched cohort study in Sweden. Data from the Swedish Prescribed Drug Register identified all women exposed to systemic MHT in 2005-2012. Group-level matching (1:3 ratio) was used to select women unexposed to MHT from the same study base, matched for history of delivery, thrombotic events, hysterectomy, age, smoking- and alcohol related diseases, obesity, and diabetes. Conditional logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Comparing 290,186 women exposed to MHT with 870,165 unexposed, MHT did not increase the OR of biliary tract cancer. The OR of gallbladder cancer was rather decreased in MHT users (OR 0.58, 95% CI 0.43-0.79), but this association became attenuated and statistically non-significant after adjusting for gallstone disease (OR 0.84, 95% CI 0.60-1.15). The OR of extra-hepatic bile duct cancers was 0.83 (95% CI 0.61-1.15). There were no clear differences when the analyses were stratified for estrogen or estrogen/progestogen combinations. MHT increased the risk of gallstone disease (OR 6.95, 95% CI 6.64-7.28).

CONCLUSIONS

Contemporary MHT does not seem to increase the risk of biliary tract cancer. The decreased risk of gallbladder cancer may be explained by the increased use of surgery for symptomatic gallstones in MHT users.

Hormone Replacement Therapy in Cancer Survivors - Review of the Literature

Rapid advance in oncology leads to increasing survival of oncologic patients. More and more of them live long enough to reach either the natural age of menopause or, as a side effect of their oncotherapy, experience the cessation of gonadal function, leading to premature ovarian insufficiency, with disturbing vasomotor symtoms and long-term negative cardiovascular and skeletal effects. Thus, an ever increasing number of cancer survivors search endocrinologic help in the form of hormone replacement therapy (HRT). The misinterpretation of the WHI (Women's Health Initiative) Study has lead to an irrational fear of female hormone replacement, both by the general population and medical professionals. It has seemed the logical and safe conclusion to many physicians to avoid HRT, supposing that this attitude definitely causes no harm, whereas the decision of prescribing estrogen alone or with progestins might bear oncologic and thromboembolic risks and may even lead to litigation in case of a potentially related complication. However, it was known even before the WHI results that premature menopause and hypogonadism decreases the life expectancy of women by years through its skeletal and cardiovascular effects, and this negative effect correlates with the length of the hypoestrogenaemic period. Therefore, the denial of HRT also needs to be supported by evidence and should be weighed againts the risks of HRT. Yet, the oncologic risk of HRT is extremely difficult to assess. In this work we review the latest evidence from in vitro experiments to clinical studies, regarding HRT in survivors of gynecologic and non-gynecologic cancers. Based on our literature research, we group tumours regarding the oncologic risk of properly chosen female hormone replacement therapy in cancer survivors as follows: ’HRT is advanageous’ (e.g. endometrial cancer type I, cervical adenocarcinoma, haematologic malignancies, local cutaneous malignant melanoma, colorectal cancer, hepatocellular cancer); ’HRT is neutral’ (e.g. BRCA 1/2 mutation carriers without cancer, endometrial cancer type II, uterinal carcinosarcoma and adenosarcoma, certain types of ovarian cancer, cervical, vaginal and vulvar squamous cell carcinoma, prolactinoma, kidney cancer, pancreatic cancer, thyroid cancer); ’HRT is relatively contraindicated’ for various reasons (e.g. leiomyosarcoma, certain types of ovarian tumours, brain tumours, advanced metastatic malignant melanoma, lung cancer, gastric cancer, bladder cancer); ’HRT is diasadvantageous and thus contraindicated’ (e.g. breast cancer, endometrial stroma sarcoma, meningioma, glioma, hormone receptor positive gastric and bladder cancer).

Menopausal Hormone Replacement Therapy and the Risk of Ovarian Cancer: A Meta-Analysis

Background: Findings by epidemiologic studies on menopausal hormone replacement therapy (HRT) and the risk of ovarian cancer are inconsistent. This study aimed to assess the association of menopausal HRT with the risk of ovarian cancer by histological subtype. Methods: A literature search was performed in PubMed, Web of Science, and EmBase for relevant articles published from inception to August 2018. Pooled relative risk ratios (RRs) with 95% confidence intervals (CIs) were determined with a random-effects model. Results: Thirty-six studies involving 4, 229, 061 participants were included in this meta-analysis. The pooled RR of ovarian cancer was 1.29 (95%CI 1.19-1.40, I ² = 57.4%) for menopausal HRT. In subgroup analysis by study design, pooled RRs of ovarian cancer in cohort and case-control studies were 1.35 (95%CI 1.19-1.53) and 1.24 (95%CI 1.11-1.38), respectively. In subgroup analysis by continent, association of menopausal HRT with ovarian cancer was significant for North America (1.41 [1.23-1.61]), Europe (1.22 [1.12-1.34]), and Asia (1.76 [1.09-2.85]), but not Australia (0.96 [0.57-1.61]). Association differed across histological subtypes. Increased risk was only found for two common types, including serous (1.50 [1.35-1.68]) and endometrioid (1.48 [1.13-1.94]) tumors. Conclusion: This meta-analysis suggests that menopausal HRT may increase the risk of ovarian cancer, especially for serous and endometrioid tumors.

Panels of tumor-derived RNA markers in peripheral blood of patients with non-small cell lung cancer: their dependence on age, gender and clinical stages

Peripheral blood mononuclear cell (PBMC)-derived gene signatures were investigated for their potential use in the early detection of non-small cell lung cancer (NSCLC). In our study, 187 patients with NSCLC and 310 age- and gender-matched controls, and an independent set containing 29 patients for validation were included. Eight significant NSCLC-associated genes were identified, including DUSP6, EIF2S3, GRB2, MDM2, NF1, POLDIP2, RNF4, and WEE1. The logistic model containing these significant markers was able to distinguish subjects with NSCLC from controls with an excellent performance, 80.7% sensitivity, 90.6% specificity, and an area under the receiver operating characteristic curve (AUC) of 0.924. Repeated random sub-sampling for 100 times was used to validate the performance of classification training models with an average AUC of 0.92. Additional cross-validation using the independent set resulted in the sensitivity 75.86%. Furthermore, six age/gender-dependent genes: CPEB4, EIF2S3, GRB2, MCM4, RNF4, and STAT2 were identified using age and gender stratification approach. STAT2 and WEE1 were explored as stage-dependent using stage-stratified subpopulation. We conclude that these logistic models using different signatures for total and stratified samples are potential complementary tools for assessing the risk of NSCLC.

Use of hormone replacement therapy improves the prognosis in patients with colorectal cancer: A population-based study in Sweden

The association between hormone therapy (estrogen, with or without progesterone) and colorectal cancer (CRC) has received considerable scientific interest but previous research has generated inconsistent results. We aimed to examine whether post-diagnostic use of hormone therapy might protect against CRC mortality and all-cause mortality. Women diagnosed with CRC between January 2007 and December 2012 were identified from the Swedish Cancer Registry and linked to the Swedish Prescribed Drug Register to retrieve hormone therapy users after CRC diagnosis. A total of 1,109 patients were diagnosed with CRC and used hormone therapy post-CRC diagnosis. Time-dependent Cox regression with 1-year lag was used to calculate the hazard ratio (HR) of CRC mortality and all-cause mortality associated with post-diagnostic use of hormone therapy. Use of hormone therapy after CRC diagnosis was associated with a 26% risk reduction in CRC mortality (HR = 0.67, 95%CI 0.56-0.79) and a 30% risk reduction in all-cause mortality (HR = 0.68, 95%CI 0.59-0.77). The risk reduction was even stronger if women also used hormone therapy before the diagnosis of CRC and for women with higher cumulative doses of hormone therapy. The risk reduction was largely consistent irrespective of CRC severity. Our data suggests that use of hormone therapy after CRC diagnosis is associated with a decreased risk of cancer-related mortality and all-cause mortality.

Influence of estrogen in non-small cell lung cancer and its clinical implications

Lung cancer (LC) is the leading cause of cancer death in men worldwide and has significantly increased in women. Differences in non-small cell lung cancer (NSCLC) behavior, prognosis, and response to treatment have been reported by sex and hormonal status, with premenopausal women presenting the worst prognosis compared to postmenopausal women and men. Additionally, the use of hormonal replacement therapy significantly increases NSCLC mortality; supporting the role of estrogen signaling in the pathogenesis of LC. The mechanisms by which estrogen promotes lung carcinogenesis have not been fully elucidated. Estrogen, through its receptor, can stimulate LC cell proliferation, death resistance, angiogenesis, migration and metastasis. Estrogen also induces expression of pro-inflammatory proteins and ligands that promote tumor evasion, suggesting that estrogen might modify the microenvironment and anti-tumor immune response. Recent reports have shown an interaction between the epidermal growth factor receptor (EGFR) pathway and estrogen signaling in lung adenocarcinoma, whence, combined treatment based on tyrosine kinase inhibitors (TKIs) and antiestrogen therapy is beginning to be evaluated. This review focuses on the differences in NSCLC behavior by sex and hormonal status, highlighting the role of estrogen and its receptors in lung carcinogenesis and LC prognosis. Due to the importance of estrogen in NSCLC development and progression we finally discuss the potential of antiestrogen therapy in LC treatment and show the results from preclinical and clinical trials.

Change in risk of breast cancer after receiving hormone replacement therapy by considering effect-modifiers: a systematic review and dose-response meta-analysis of prospective studies

We synthesize the current literatures and use the power of meta-analysis to examine trends on association between hormone replacement therapy (HRT) and the risk of breast cancer (BC). We performed a comprehensive literature search using PubMed, EMBASE, and Web of Science from their inception until Jan 2017. Prospective studies that provided adjusted risk estimates of HRT and BC risk were eligible. Categorical and dose-response meta-analyses followed the PRISMA were conducted using random effects model and restricted cubic spline model, respectively. Forty-seven publications from thirty-five unique studies were included, involving 3,898,376 of participants and 87,845 of BC cases. Compared with non-users, RR for current estrogen-only therapy (ET) users was 1.14 (95% confidence interval (CI) = 1.05–1.22), and for per year increases was 1.02 (95% CI = 1.02–1.02). Moreover, RR for current estrogen plus progestin therapy (EPT) users was 1.76, (95% CI = 1.56–1.96), and for per year increases was 1.08 (95% CI = 1.08–1.08). Dose-response analyses revealed 8–10 years’ onset peaks, and indicated residual increased BC risk remained after stopping use of ET regimen rather than for EPT. Effect-modifiers like BMI, duration of use, race/ethnicity, routes of administration were recognized. In Conclusions, current use of EP or EPT and ever use of tibolone are associated with an elevated risk of BC. Compared with slim HRT users and non-users, lower BC risks were found among overweight/obese HRT users and former EPT users, respectively. Both ET and EPT users are associated with higher risk of lobular BC than ductal BC, and more ER-positive than negative BC cases were detected among EPT users.

Alpinumisoflavone inhibits osteoclast differentiation and exerts anti-osteoporotic effect in ovariectomized mice

Alpinumisoflavone (AIF), a naturally occurring flavonoid compound exacted from Derris eriocarpa, has been found to have a number of pharmacological activities. However, its role in bone disorder has not been investigated. The aim of this study is to evaluate the osteoprotective effect of AIF on ovariectomy-induced bone loss in mice model and related underlying mechanisms. Our study provides experimental evidence that AIF could regulate the remodeling process of bone and exert osteoprotective effect against ovariectomy-induced bone loss. Moreover, our results show that AIF suppresses osteoclast differentiation by attenuating RANKL-induced activation of p38, ERK and JNK pathways and consequently represses the expression of c-Fos and NFATc1.

Exploring estrogenic activity in lung cancer

It is well known that a connection between xenobiotics inhalation, especially tobacco combustion and Lung Cancer development is strongly significant and indisputable. However, recent studies provide evidence indicating that another factors such as, estrogens are also involved in lung carcinoma biology and metabolism. Although the status of estrogen receptors (ER), in both cancerous and healthy lung tissue has been well documented, there is still inconclusive data with respect of which isoform of the receptor is present in the lungs. However according to several studies, ERβ appears to be predominant form. Apart from ERs, estrogens can work through a recently discovered G-coupled estrogen receptor. Binding with both types of the receptors causes a signal, which leads to i.e. enhanced cell proliferation. There are many published reports which suggest that estrogen can be synthesized in situ in lung cancer. Some disturbances in the activity and expression levels of enzymes involved in estrogen synthesis were proved. This suggests that increased amounts of sex-steroid hormones can affect cells biology and be the reason of the accelerated development and pathogenesis of lung cancer. There also exist phenomena which associate estrogenic metabolism and tobacco combustion and its carcinogenic influence on the lungs. Compounds present in cigarette smoke induce the activity of CYP1B1, the enzyme responsible for estrogenic metabolism and synthesis of their cateholic derivatives. These structures during their redox cycle are able to release reactive oxygen species or form DNA adduct, which generally leads to destruction of genetic material. This process may explain the synergistic effect of smoking and estrogens on estrogen-dependent lung cancer development.

Risk factors for lung cancer worldwide

Lung cancer is the most frequent malignant neoplasm in most countries, and the main cancer-related cause of mortality worldwide in both sexes combined.The geographic and temporal patterns of lung cancer incidence, as well as lung cancer mortality, on a population level are chiefly determined by tobacco consumption, the main aetiological factor in lung carcinogenesis.Other factors such as genetic susceptibility, poor diet, occupational exposures and air pollution may act independently or in concert with tobacco smoking in shaping the descriptive epidemiology of lung cancer. Moreover, novel approaches in the classification of lung cancer based on molecular techniques have started to bring new insights to its aetiology, in particular among nonsmokers. Despite the success in delineation of tobacco smoking as the major risk factor for lung cancer, this highly preventable disease remains among the most common and most lethal cancers globally.Future preventive efforts and research need to focus on non-cigarette tobacco smoking products, as well as better understanding of risk factors underlying lung carcinogenesis in never-smokers.

The Influence of Hormonal Factors on the Risk of Developing Cervical Cancer and Pre-Cancer: Results from the EPIC Cohort

BACKGROUND

In addition to HPV, high parity and hormonal contraceptives have been associated with cervical cancer (CC). However, most of the evidence comes from retrospective case-control studies. The aim of this study is to prospectively evaluate associations between hormonal factors and risk of developing cervical intraepithelial neoplasia grade 3 (CIN3)/carcinoma in situ (CIS) and invasive cervical cancer (ICC).

METHODS AND FINDINGS

We followed a cohort of 308,036 women recruited in the European Prospective Investigation into Cancer and Nutrition (EPIC) Study. At enrollment, participants completed a questionnaire and provided serum. After a 9-year median follow-up, 261 ICC and 804 CIN3/CIS cases were reported. In a nested case-control study, the sera from 609 cases and 1,218 matched controls were tested for L1 antibodies against HPV types 11,16,18,31,33,35,45,52,58, and antibodies against Chlamydia trachomatis and Human herpesvirus 2. Multivariate analyses were performed to estimate hazard ratios (HR), odds ratios (OR) and corresponding 95% confidence intervals (CI). The cohort analysis showed that number of full-term pregnancies was positively associated with CIN3/CIS risk (p-trend = 0.03). Duration of oral contraceptives use was associated with a significantly increased risk of both CIN3/CIS and ICC (HR = 1.6 and HR = 1.8 respectively for ≥ 15 years versus never use). Ever use of menopausal hormone therapy was associated with a reduced risk of ICC (HR = 0.5, 95%CI: 0.4-0.8). A non-significant reduced risk of ICC with ever use of intrauterine devices (IUD) was found in the nested case-control analysis (OR = 0.6). Analyses restricted to all cases and HPV seropositive controls yielded similar results, revealing a significant inverse association with IUD for combined CIN3/CIS and ICC (OR = 0.7).

CONCLUSIONS

Even though HPV is the necessary cause of CC, our results suggest that several hormonal factors are risk factors for cervical carcinogenesis. Adherence to current cervical cancer screening guidelines should minimize the increased risk of CC associated with these hormonal risk factors.

Hormonal Replacement Therapy and the Risk of Lung Cancer in Women: An Adaptive Meta-analysis of Cohort Studies

Objectives:

Approximately 10% to 15% of lung cancer cases occur in never-smokers. Hormonal factors have been suggested to lead to an elevated risk of lung cancer in women. This systematic review (SR) aimed to investigate the association between hormonal replacement therapy (HRT) and the risk of lung cancer in women using cohort studies.

Methods:

We first obtained previous SR articles on this topic. Based on these studies we made a list of refereed, cited, and related articles using the PubMed and Scopus databases. All cohort studies that evaluated the relative risk of HRT exposure on lung cancer occurrence in women were selected. Estimate of summary effect size (sES) with 95% confidence intervals (CIs) were calculated.

Results:

A total of 14 cohort studies were finally selected. A random effect model was applied due to heterogeneity (I-squared, 64.3%). The sES of the 14 articles evaluating the impact of HRT exposure on lung cancer occurrence in women indicated no statistically significant increase in lung cancer risk (sES, 0.99; 95% CI, 0.90 to 1.09).

Conclusions:

These results showed that HRT history had no effect on the risk of lung cancer in women, even though the sES of case-control studies described in previous SR articles indicated that HRT had a protective effect against lung cancer. It is necessary to conduct a pooled analysis of cohort studies.

Estrogen and cancers of the colorectum, breast, and lung in postmenopausal women

As estrogens play an important role in maintaining physiological function in various organs, the estrogen decrease after menopause is thought to cause various diseases frequently observed in postmenopausal or elderly women. With the aging of society and a decrease in infectious or vascular diseases, neoplasms have now become the most frequent cause of death in Japan. Cancers of the colorectum, breast, and lung have been rapidly increasing both in incidence and death, especially among postmenopausal women. Interestingly, all three of these cancers are associated with estrogens. In premenopausal women, ovarian estrogens plays major roles in the female reproductive organs through the classic estrogen receptor, ER-α. In postmenopausal women, however, estrogens produced/activated by peripherally localized estrogen-metabolizing enzymes such as aromatase, which converts androgen into estrogens, are thought to play physiologically and pathobiologically important roles in various organs through second ER, namely ER-β, distributing systemically. In this article, the association of estrogens with these cancers in postmenopausal or elderly women are reviewed, especially focusing on the role of ER-β and peripheral estrogen metabolism. The possibility of prevention or treatment of these diseases through estrogenic control is also discussed.

Reproductive factors and risk of biliary tract cancer in a population-based study

BACKGROUND

The strong female predominance of biliary tract cancer (BTC) may be related to reproductive factors. We aimed to clarify whether parity or age at first birth influence the risk of BTC.

METHODS

This was a population-based, case-control study including Swedish female and male cases of cancer of the gallbladder (GBC), extra hepatic bile ducts (EHCC), or the ampulla of Vater (AVC) between 1960 and 2008. For each case, 10 age- and sex-matched controls were randomly selected. Conditional logistic regression was used to calculate odds ratios (ORs) with 95% confidence intervals (CIs), adjusted for potential confounders.

RESULTS

In total, 1169 cases of GBC, 432 cases of EHCC and 295 cases of AVC were included. Multi- and nulliparous women and men had an increased risk of all tumor locations in the biliary tract compared to uniparous women and men, respectively. Whereas higher age at first birth was associated with a decreased risk of GBC in women, no such association was found in men. There were no clear differences in the risk of EHCC and AVC between women and men.

CONCLUSION

Sex hormones may play a role in the etiology of GBC. The associations between reproductive factors and EHCC and AVC are similar in women and men, which do not support the sex hormone hypothesis.

Relationship between female hormonal and menstrual factors and pancreatic cancer: a meta-analysis of observational studies

The objective of this study was to assess the relationship between female hormone and menstrual factors and pancreatic cancer (PC) through a meta-analysis of observational studies. We undertook a systematic literature search up to July 10, 2014 in PubMed and EMBASE databases. Combined relative risks (RRs) were estimated by random-effects models. Subgroup analysis was performed by study design, source of control, and geographic regions. Sensitivity analyses and publication bias were utilized to evaluate the robustness of our results. A total of 27 case-control and cohort studies were retrieved for this meta-analysis. No significant associations were observed between the risk of PC and age at menarche (RR = 0.94, 95% confidence interval [CI] 0.83-1.07), age at menopause (RR = 0.98, 95% CI 0.85-1.13), hysterectomy (RR = 0.97, 95% CI 0.84-1.11), oophorectomy (RR = 1.02, 95% CI 0.82-1.26), hormone replacement therapy (RR = 0.97, 95% CI 0.87-1.08), and oral contraceptives (RR = 1.09, 95% CI 0.96-1.23). This meta-analysis of observational studies does not support the hypothesis that exogenous hormone use and menstrual factors are associated with PC.

Parity and pancreatic cancer risk: evidence from a meta-analysis of twenty epidemiologic studies

Multiple studies have hypothesized parity is associated with pancreatic cancer risk but obtained conflicting results. We conducted a meta-analysis (including a dose-response approach) of current available epidemiologic studies to investigate the association between parity and risk of pancreatic cancer. Ten cohort studies and ten case-control studies including 8205 cases were eligible for inclusion. The combined RR (relative risk) of pancreatic cancer for the parous vs. nulliparous was 0.91 (95% CI, confidence interval = 0.85–0.97, I² = 39.0%, P_h = 0.01). We observed an inverse association between giving birth to two children pancreatic cancer risk with RR of 0.86 (95% CI = 0.80–0.93, I² = 8.7%, P_h = 0.36). And no evidence supported there was non-linear (P = 0.33) or linear relationship (P = 0.14) between number of parity and risk of pancreatic cancer. Findings from this meta-analysis indicate that giving birth to two children has the lowest pancreatic cancer risk, mechanism of this protective effect needs further investigation.

Targeting the estrogen pathway for the treatment and prevention of lung cancer

The estrogen signaling pathway is involved in the biology of non-small-cell lung cancer and represents a novel therapeutic target for lung cancer. This is supported by epidemiological evidence, preclinical studies and recent data from clinical trials. Antiestrogens and inhibitors of estrogen synthesis have been shown to inhibit lung tumor growth as well as prevent lung tumorigenesis in preclinical models both in vitro and in vivo. Two clinical trials testing the effectiveness of hormonal strategies in advanced non-small-cell lung cancer have recently been completed with promising results. Future work in this field should focus on identification of patients that would benefit from hormone modulators so that they can be used earlier in the course of disease or for chemoprevention.

Reproductive and exogenous hormone factors in relation to risk of meningioma in women: a meta-analysis

BACKGROUND AND OBJECTIVE

A number of studies have focused on the association between oral contraceptive (OC), hormonal replacement therapy (HRT) and reproductive factors and meningioma risk, but the results were inconsistent. Thus, a meta-analysis was performed to obtain more precise estimates of risk.

METHODS

We conducted a literature search using PubMed and EMBASE databases to July 2013, without any limitations. Random effects models were used to summarize results.

RESULTS

Twelve case-control and six cohort studies were included in this meta-analysis. We found that an increased risk of meningioma was associated with HRT use(RR = 1.19, 95% CI = 1.01-1.40), postmenopausal women(RR = 1.32, 95% CI = 1.07-1.64) and parity(RR = 1.18, 95% CI = 1.00-1.40).No significant associations were observed for OC use (RR = 0.93, 95% CI = 0.83-1.03), age at menarche(RR = 1.06, 95% CI = 0.92-1.21), age at menopause(RR = 1.03, 95% CI = 0.81-1.30), or age at first birth(RR = 0.94, 95% CI = 0.80-1.10).

CONCLUSION

In conclusion, the results of our study support the hypothesis that longer exposure to effect of female sex hormones may increase the risk of meningioma in women, yet additional studies are warranted to confirm our findings and identify the underlying biological mechanisms.

Non-steroidal anti-inflammatory drug use and cervical cancer risk: a case-control study using the Clinical Practice Research Datalink

PURPOSE

Non-steroidal anti-inflammatory drugs (NSAIDs) have many anticarcinogenic properties via the inhibition of cyclooxygenase 2 (COX-2). Only one study, a cohort study examining risk of all cancers, investigated their role in cervical cancer with inconsistent findings between non-aspirin NSAIDs and aspirin. The aim of this study was to further investigate NSAID/aspirin use and cervical cancer risk.

METHODS

Using the United Kingdom Clinical Practice Research Datalink, 724 women diagnosed with cervical cancer between 1 January, 1995 and December 2010 were compared to 3479 women (without cervical cancer) matched on year of birth and general practice. Conditional logistic regression analysis adjusted for smoking, sexually transmitted infections, HRT and contraceptive use, was used to calculate odds ratios (OR) and 95% confidence intervals (CI) for cervical cancer risk among users of any oral NSAIDs, non-aspirin NSAIDs and aspirin, as assessed from primary care prescribing data.

RESULTS

Excluding the year prior to diagnosis, there was no association in adjusted analyses between ever vs. never use of an NSAID (OR 0.92, 95% CI 0.77-1.09), non-aspirin NSAID (OR 0.95, 95% CI 0.80-1.13) or low-dose aspirin (OR 1.07, 0.80-1.44) and cervical cancer risk. In analysis of daily defined doses, there was no association with cervical cancer risk comparing the highest users to non-users of NSAIDs (OR 0.98, 95% CI 0.69-1.39) or non-aspirin NSAIDs (OR 1.00, 95% CI 0.70-1.43) or low-dose aspirin (OR 1.04, 95% CI 0.59-1.81).

CONCLUSION

This large historical cohort study found no evidence of an association between non-aspirin NSAID or aspirin use and cervical cancer risk.

Hormone replacement therapy in females can decrease the risk of lung cancer: a meta-analysis

The purpose of the present meta-analysis was to determine the relationship between hormone replacement therapy (HRT) and lung cancer risk in females. Publications were reviewed and obtained through a PubMed, EMBASE database and Cochrane Library literature search up to May, 2012. The detailed numbers of patients in different groups, odd ratios (ORs) and corresponding 95% confidence intervals (CIs) were collected and estimated using a random-effects model. Twenty five studies entered into the meta-analysis. The total number of participates and lung cancer patients was 656,403 and 11,442, respectively. The OR of all 25 studies was 0.91 (95%CI  = 0.83 to 0.99) and P value was 0.033. In stratified analyses, the positive association between HRT use and decreased lung cancer risk was also found in the patients with BMI<25 kg/m² (OR = 0.65, P = 0.000), and never smokers patients (OR = 0.86, P = 0.042). However, HRT use in patients with artificial menopause could increase the lung cancer risk, OR = 1.51(P = 0.001). The result of Egger's test did not show any evidence of publican bias (P = 0.069). In conclusion, our meta-analysis on HRT and lung cancer risk suggests that HRT use is correlated with decreased lung cancer risk in female, especially in female with BMI<25 kg/m² and never smokers.

Exogenous and endogenous hormones in relation to glioma in women: a meta-analysis of 11 case-control studies

BACKGROUND AND OBJECTIVE

Previous investigations of glioma risk in women have focused on oral contraceptive (OC), hormone replacement therapy (HRT), and reproductive factors. However, the results of published studies were inconclusive and inconsistent. Thus, a meta-analysis based on published case-control studies was performed to assess the role of exogenous and endogenous hormones factors in glioma risk.

METHODS

The PubMed and EMBASE databases were searched without any restrictions on language or publication year. Reference lists from retrieved articles were also reviewed. We included case-control studies reporting relative risks (RRs) with corresponding 95% confidence intervals (CIs) (or data to calculate them) between oral contraceptive (OC) and hormone replacement therapy (HRT) use, reproductive factors and glioma. Random-effects models were used to calculate the summary risk estimates.

RESULTS

Finally, 11 eligible studies with 4860 cases and 14,740 controls were identified. A lower risk of glioma was observed among women who were ever users of exogenous hormones (OC RR = 0.707, 95% CI = 0.604-0.828; HRT: RR = 0.683, 95% CI = 0.577-0.808) compared with never users. An increased glioma risk was associated with older age at menarche (RR = 1.401, 95% CI = 1.052-1.865). No association was observed for menopause status, parous status, age at menopause, or age at first birth and glioma risk.

CONCLUSION

The results of our study support the hypothesis female sex hormones play a role in the development of glioma in women. Additional studies are warranted to validate the conclusion from this meta-analysis and clarity the underlying mechanisms.