Expression levels of estrogen receptor beta in conjunction with aromatase predict survival in non-small cell lung cancer

Estrogen signaling pathways may play a significant role in the pathogenesis of non-small cell lung cancers (NSCLC) as evidenced by the expression of aromatase and estrogen receptors (ERα and ERβ) in many of these tumors. Here we examine whether ERα and ERβ levels in conjunction with aromatase define patient groups with respect to survival outcomes and possible treatment regimens. Immunohistochemistry was performed on a high-density tissue microarray with resulting data and clinical information available for 377 patients. Patients were subdivided by gender, age and tumor histology, and survival data was determined using the Cox proportional hazards model and Kaplan-Meier curves. Neither ERα nor ERβ alone was predictor of survival in NSCLC. However, when coupled with aromatase expression, higher ERβ levels predicted worse survival in patients whose tumors expressed higher levels of aromatase. Although this finding was present in patients of both genders, it was especially pronounced in women ≥ 65 years old, where higher expression of both ERβ and aromatase indicated a markedly worse survival rate than that determined by aromatase alone. Expression of ERβ together with aromatase has predictive value for survival in different gender and age subgroups of NSCLC patients. This predictive value is stronger than each individual marker alone. Our results suggest treatment with aromatase inhibitors alone or combined with estrogen receptor modulators may be of benefit in some subpopulations of these patients.     

Clinical value of the wild-type estrogen receptor beta expression in breast cancer

To estimate the clinical value of estrogen receptor (ER) beta expression in breast cancer we used an immunohistochemical method to detect the wild-type ERbeta in 88 primary breast cancers. We used a highly specific polyclonal antibody to the carboxyl terminus of wild-type ERbeta. This antibody reacted with neither other variant forms of ERbeta nor any part of ERalpha. Slides were evaluated on a scale representing the estimated proportion and intensity of positive-staining tumor cells. Positive staining could be seen in 52 (59.1%) of 88 breast cancers; 36 (40.9%) were negative. Although there was no correlation between ERbeta staining and age, node status, tumor size, histological grade, or progesterone receptor (PgR)-enzyme immunoassay (EIA) status, we did observe a significant correlation with ERalpha-EIA (Fisher's exact probability test: P=0.0169). Moreover, ERbeta positive cases showed a better prognosis than negative cases in disease-free survival rate (Logrank test: P=0.0662, Breslow-Gehan-Wilcoxson test: P=0.0318). Our data demonstrated the possibility that wild-type ERbeta protein expression could be used as a good prognostic indicator for breast cancer.     

Oestrogen receptor beta over expression in males with non-small cell lung cancer is associated with better survival

BACKGROUND: Adenocarcinoma of the lung is more frequent in females than in males and the association with smoking is less pronounced than for the other histological subtypes of lung cancer. Oestrogen induction of cell proliferation has been found in breast adenocarcinomas, and since oestrogen receptors (ER) have been demonstrated in lung tumours, a similar role of oestrogens in the development of lung cancer has been suggested. We examined the expression of ERalpha, ERbeta and progesterone in a well defined cohort of patients with NSCLC with more than 15 years of follow up, and related the results to gender and survival. METHODS: Paraffin embedded, histological material was collected from 104 patients (71 men and 33 women), operated in the period 1989-1992 for NSCLC (56 squamous cell carcinomas, 40 adenocarcinomas and 8 large cell carcinomas). ERalpha, ERbeta and progesterone were immunohistochemically analysed. Staining frequency and intensity was scored semi-quantitatively. A tumour was defined as positive when more than 10% of the tumour cells were positive with at least a weak nuclear staining. Kaplan-Meier survival curves were generated to evaluate the significance of ERalpha, ERbeta and progesterone expression for the prognosis. RESULTS: ERbeta positivity was demonstrated in 69% (72 of 104) of the tumours. There was no statistically significant correlation between ERbeta positivity and age, gender, stage, or histology. After adjusting for gender, age, stage at diagnosis and histology there was no difference in survival between subjects with ERbeta positive and ERbeta negative tumours. When stratifying by gender women with ERbeta-negative tumours had a non-significant (P=0.26) decrease in mortality compared with women with ERbeta positive tumours. In contrast, men with ERbeta positive tumours had a significantly reduced mortality (P=0.035) compared to men with ERbeta negative tumours. Using multivariate regression analysis the interaction between gender and positive ERbeta staining was the only significant prognostic factor. There was no correlation between the ERalpha immunohistochemical staining and any of the clinical variables, including survival. None of the 104 patients had tumours positive for progesterone. CONCLUSION: The presence of ERbeta in a tumour seems to be a positive prognostic factor for men with non-small cell lung cancer. The finding confirms another recent study and suggests that the relation between oestrogens and lung cancer be investigated further.     

Serum estrogen receptor beta mediated bioactivity correlates with poor outcome in lung cancer patients

Objectives

The role of estrogen signaling in lung cancer remains unresolved. We investigate the influence of serum estrogenic compounds and estrogen receptor (ERα and ERβ) mediated bioactivity on lung cancer outcomes.

Materials and methods

Serum samples were collected from 222 postmenopausal Chinese patients diagnosed with lung cancer in five Singapore hospitals. Levels of the estrogenic compounds estradiol and estrone were measured using liquid chromatography tandem mass spectrometry. Free estradiol levels were calculated based on sex hormone binding globulin levels. ERα- and ERβ-mediated bioactivity in serum samples were analyzed using reporter gene bioassays in human cells.

Results and conclusion

High ERβ-mediated bioactivity predicted poorer lung cancer survival (p = 0.001) on multivariable Cox regression analysis with adjustment for age, stage of tumor, smoking status, body mass index and histology. In comparison, levels of estrogens and ERα-mediated bioactivity were not associated with prognosis. Compared to the lowest tertile of ERβ-mediated bioactivity, patients in the middle and highest tertiles had HR (95%CI) 1.60 (1.10–2.33) and 1.93 (1.32–2.82) (p for trend = 0.001) higher risk of death from lung cancer. Using Kaplan–Meier survival curves, patients with high ERβ-mediated bioactivity correlated with poorer overall survival (p = 0.033). ERβ-mediated bioactivity did not differ in terms of age, use of hormone replacement therapy, smoking, stage of tumor or histological subtype. High ERβ-mediated bioactivity levels in patients’ serum were associated with poorer prognosis in lung cancer patients. Our findings suggest that that compound(s) other than endogenous estrogens may be exerting this ERβ bioactivity and studies to identify these compounds or groups of compounds need to be performed. Furthermore, the measurement of ERβ activity in sera could potentially serve as a prognostic marker to predict lung cancer survival, and selective blockage of ERβ signaling may have a role in lung cancer therapy.     

Differential role of estrogen receptor beta in early versus metastatic non-small cell lung cancer

Although women have an increased susceptibility to lung cancer, they also have a favorable clinical outcome. This may in part be due to female specific genetic and hormonal factors. In the present study, expression of ER-beta was investigated by immunohistochemistry using tissue samples from two cohorts: non-small cell lung cancer (NSCLC) diagnosed in 1999 in Manitoba and advanced NSCLC patients from the NCIC-CTG BR.18 trial. In the Manitoba cohort assessable tissue samples available in 79 patients (32 females and 47 males) and the majority (75%) had early stage disease. Fifty-one percent of patients expressed high levels of ER-beta (defined by ≥60, the median immunohistochemistry score) and its expression was comparable in males and females. The 3-year overall survival of the group was 53% and males had significantly worse survival compared to females (HR=2.37, 95%CI 1.15–4.91, P=0.02). Higher ER-beta 1 expression was associated with better survival in both univariate (HR=0.41, 95%CI 0.21–0.80, P=0.009) and in multivariate (HR=0.37, 95%CI 0.18–0.77, P=0.008) analysis. In the NCIC-CTG cohort that were more often later stage, assessable tissue samples from 48 cases were available however higher ER beta 1 expression correlated with poorer survival (HR= 1.94, 95%CI 1.01–3.75 P=0.047). These results suggest a differential impact of ER-beta 1 expression on clinical outcome by disease stage, that needs to be explored further and may explain contradictory observations reported in the literature.     

Androgen receptor in estrogen receptor positive breast cancer: Beyond expression

In recent years, new therapeutic approaches have reshaped the overall strategy of breast cancer (BC) treatment and have markedly improved patient survival. This is, in part, due to novel therapies for estrogen receptor (ER)-positive BC. Unfortunately, many patients present de novo resistance to these therapies or develop an acquired resistance over time. Therefore, research is now focused on discovering new molecular targets to overcome these resistances. Interestingly, preclinical and clinical studies have shown a critical role for the cross-talk between androgen receptor (AR) and ER in luminal-like BC. AR is expressed in >60% of BC and in up to 90% of ERα-positive tumors. Multiple studies suggest that AR is associated with a favorable prognosis. However, AR overexpression and, in particular, the high AR:ER ratio, seem to be involved in resistance to hormonal treatment. In this setting, a group of BCs could benefit from AR-inhibitors; nevertheless, some ER-positive BC patients do not seem to benefit from this strategy. Therefore, it is crucial to identify biomarkers that would enable the selection of patients who might benefit from combination treatment with ER and AR inhibitors.     

Clinical significance of estrogen receptor beta in breast cancer

Ever since the estrogen receptor (ER) beta was discovered in 1996, we have been trying to determine its value as a prognostic and/or predictive factor in breast cancer and its potential as a novel target for pharmacological intervention. Recent progress in cellular experiments has shown that ERbeta works as counter partner of ERalpha through inhibition of the transactivating function of ERalpha by heterodimerization, distinct regulation on several specific promoters by ERalpha or ERbeta, and ERbeta-specific regulated genes which are probably related to its anti-proliferative properties. Accumulated data from protein studies in breast cancer tissues indicate that positive expression of ERbeta appears to correlate with a favorable prognosis. Although the number of studies is small, a positive response to tamoxifen treatment is observed in both ERalpha- and ERbeta-positive populations. The significance of ERbeta2/cx, a splicing variant of ERbeta, remains controversial and needs to be analyzed in further studies. We postulate that a combined evaluation of ERbetacx with progesterone receptor may help the stratification of ERalpha-positive breast cancer. Epidemiological studies of hormone replacement therapy and isoflavone (genistein) consumption indicate the possible contribution of ERbeta-specific signaling in breast cancer prevention. A selective estrogen receptor modulator, which works as an antagonist of ERalpha and an agonist of ERbeta, may be a promising chemo-preventive treatment.     

Wild-type estrogen receptor beta expression in normal and neoplastic paraffin-embedded tissues

Recently, several antibodies have allowed the detection of estrogen receptor beta (ER-beta) in paraffin-embedded tissue; however, these attempts have failed to specifically identify the wild-type form and revealed technical difficulties such as the necessity for alterations to standard staining protocols and amplification detection systems. The aim of this study was to generate a monoclonal antibody that could provide enhanced sensitivity for detection of ER-beta in paraffin embedded tissues. A 130-amino acid region of the C-terminus of ER-beta was expressed as a fusion protein and used as an antigen to generate monoclonal antibodies. Immunohistochemical analysis of ER-beta using clone EMR02 in normal and inflamed tissues demonstrated nuclear staining. In benign and malignant tumors, variable intensities of staining and patterns of nuclear reactivity were observed between cases. Intense ER-beta positivity was also observed in tumor-infiltrating lymphocytes. Mapping studies by ELISA and Western blotting have identified specific reactivity of EMR02 to a 17-amino acid sequence of the full-length wild-type ER-beta protein (ERbetawt). Our results show that clone EMR02 is a sensitive tool for the detection of ERbetawt in paraffin-embedded tissues. This preliminary study also supports its use in immunohistochemical studies to determine the role of ERbetawt as a tumor prognostic marker and a possible therapeutic target.     

ERβ与原发性肝癌研究进展

雌激素通过与特定的雌激素受体相互作用发挥重要的作用。雌激素受体B（ERβ）是甾体激素受体超家族成员ER的一种亚型，自1996年被发现以来，其表达与变化与肿瘤各组织病理变化的关系及其作为肿瘤预警因子和可能的药物治疗靶点越来越受到关注。ERβ在正常及异常组织表达广泛，说明其具有重要的生理和病理意义。原发性肝癌早期症状不明显，导致其确诊时往往已属晚期，而失去局部治疗的机会。因此探索全身治疗包括化疗和生物治疗以及增加分子生物水平预后指标，将是今后影响癌症治疗的关键因素。ERβ与肝癌的关系已越来越受到研究界的关注。     

Hormone therapy and estrogen receptor expression in breast cancer

Postmenopausal hormone therapy (HT) may increase breast cancer risk and influence tumor characteristics. We investigated 321 postmenopausal women aged 50-65 years, with breast cancer, diagnosed and treated at Radiumhemmet, Karolinska Hospital, during 1993-1997. In women using HT (n =90) estrogen receptor concentration (ER) at diagnosis were lower than in non-users (n =135) (1.17 vs 1.70 fmol/microg; p <0.05). HT users also had a tendency to less multifocal (5 vs 12%) (p <0.05) and metastatic disease (5% vs 2%) however this was not statistically significant. The estrogen receptor expression is always considered in the judgement on hormone dependency and the clinical decision on adjuvant endocrine therapy. A suppression of ER during HT could tentatively influence the treatment decisions in breast cancer patients and maybe disregard patients from endocrine treatment.     

雌激素受体β蛋白在乳腺癌中表达的意义

目的:检测乳腺癌组织中雌激素受体β(ERβ)蛋白的表达情况,并分析其与乳腺癌临床病理特性的关系。方法:采用免疫组化法检测96例乳腺癌组织中ERβ蛋白的表达情况。结果:ERβ蛋白在96例乳腺癌组织标本中的阳性表达率为75·0%(72/96),癌旁组织中的阳性表达率为90·5%(57/63),二者差别具有显著性(P<0·05);ERβ蛋白表达水平与患者乳癌组织中的ERα蛋白水平、PR蛋白水平及组织学分级相关(P<0·05),与年龄、肿瘤大小、腋淋巴结转移、病理分型、绝经状态无关(P>0·05)。结论:ERβ在乳腺癌癌旁组织内广泛表达,在癌组织内亦有表达,但阳性表达率低于癌旁组织;ERβ蛋白的阳性表达可能是乳腺癌预后良好的一项参考指标。     

Expression of estrogen receptor beta and phosphorylation of estrogen receptor alpha serine 167 correlate with progression-free survival in patients with metastatic breast cancer treated with aromatase inhibitors

Aromatase inhibitor (AI) is widely used as an endocrine treatment in postmenopausal patients with hormone receptor-positive breast cancer. To identify useful prognostic factors for patients with metastatic breast cancer treated with AI therapy, we investigated the association between several hormone receptor-related factors and prognosis. The expressions of estrogen receptor-α (ERα), ERβ, progesterone receptor, the phosphorylation of ERα serine 118 (Ser118) and ERα Ser167 were examined using immunohistochemical techniques for the primary tumors of 41 patients with metastatic breast cancer who received first-line AI therapy after relapse. To assess the associations of protein expression and phosphorylation levels with progression-free survival (PFS), the levels of each factor were categorized into low and high values at optimal cutoff points. In univariate analysis, high ERα expression and high ERα Ser167 phosphorylation correlated with longer PFS (p = 0.016 and 0.013, respectively). In multivariate analysis, low ERβ expression and high ERα Ser167 phosphorylation correlated with longer PFS (p = 0.031 and 0.004, respectively). Patients with both low ERβ expression and high ERα Ser167 phosphorylation had longer PFS than the others (p = 0.0107). These data suggest that the expression of ERβ and phosphorylation of ERα Ser167 may be useful prognostic factors in patients with metastatic breast cancer who received first-line AI therapy.     

非小细胞肺癌雌激素受体表达与性别关系的Meta分析

目的:评估非小细胞肺癌（non-small cell lung cancer,NSCLC）中雌激素受体（estrogen receptor,ER）表达与性别的关系。方法:通过计算机检索PubMed、EMBASE、Cochrane Library数据库,检索截止日期为2018年3月。纳入符合标准的文献,使用stata 12.0软件计算非小细胞肺癌中雌激素受体表达与性别关系的相对危险度（relative ratio,RR）。结果:共有10篇研究被提取出来,包含1 557例非小细胞肺癌患者,其中女性患者525例,男性患者1 032例。非小细胞肺癌中女性患者的雌激素受体表达阳性率明显高于男性患者［RR=1.15,95%CI（1.06~1.24）,P=0.001］,敏感性分析发现本研究的合并结果基本可靠,Egger检验、Begg检验提示本研究不存在发表偏倚。结论:雌激素受体阳性可能使女性更容易患非小细胞肺癌,导致女性肺癌发病率增高。