Estrogen Receptor Positive Breast Carcinoma Research Articles

OLFM4, LY6D and S100A7 as potent markers for distant metastasis in estrogen receptor-positive breast carcinoma.

Metastatic breast cancer is a highly lethal disease, and it is very important to evaluate the biomarkers associated with distant metastasis. However, molecular features of distant metastasis remain largely unknown in breast cancer. Estrogens play an important role in the progression of breast cancer and the majority of stage IV breast carcinomas express estrogen receptor (ER). Therefore, in this study, we examined molecular markers associated with distant metastasis in ER‐positive breast carcinoma by microarray and immunohistochemistry. When we examined the gene expression profile of ER‐positive stage IV breast carcinoma tissues (n = 7) comparing ER‐positive stage I‐III cases (n = 11) by microarray analysis, we newly identified OLFM4, LY6D and S100A7, which were closely associated with the distant metastasis. Subsequently, we performed immunohistochemistry for OLFM4, LY6D and S100A7 in 168 ER‐positive breast carcinomas. OLFM4, LY6D and S100A7 immunoreactivities were significantly associated with stage, pathological T factor, distant metastasis and Ki67 status in the ER‐positive breast carcinomas. Moreover, these immunoreactivities were significantly associated with a worse prognostic factor for distant metastasis‐free and breast cancer‐specific survival in ER‐positive stage I‐III breast cancer patients. However, when we performed immunohistochemistry for OLFM4, LY6D and S100A7 in 40 ER‐negative breast carcinomas, these immunoreactivities were not generally associated with the clinicopathological factors examined, including distant metastasis and prognosis of patients, in this study. These results suggest that OLFM4, LY6D and S100A7 immunoreactivity are associated with an aggressive phenotype of ER‐positive breast carcinoma, and these are potent markers for distant metastasis of ER‐positive breast cancer patients.

Vinorelbine-induced regression of a choroidal metastasis from primary breast carcinoma

Background Various therapeutic options exist to treat choroidal metastatic lesions. However, they are all associated with potential long-term adverse effects. This case report discusses a case of choroidal metastasis from primary breast carcinoma that regressed after single-agent chemotherapy.Case presentationWe report a case of choroidal metastasis from estrogen receptor (ER) positive breast carcinoma that became resistant to endocrine therapy. The primary malignancy was treated with surgical resection and adjuvant chemoradiation, followed by hormone therapy with various agents in combination with kinase inhibitors for ER resistance. The choroidal metastatic lesion regressed after the initiation of vinorelbine. Vinorelbine is a cytotoxic vinca alkaloid with tolerable systemic adverse effects.ConclusionsThis case report highlights the possible role of vinorelbine as a single chemotherapeutic agent for the conservative therapy of uveal metastasis from advanced breast carcinoma, irrespective of responsiveness to hormone therapy.

PAX2 expression is correlated with better survival in tamoxifen-treated breast carcinoma patients.

PAX2 (paired box gene 2) is a transcription factor, which is involved in both cell proliferation and carcinogenesis. This study aimed to investigate PAX2 expression in tamoxifen resistant (TAM-R) and tamoxifen sensitive (TAM-S) breast carcinoma patients and analyze its correlation with clinicopathological characteristics and survival. Immunohistochemical analysis was performed to evaluate PAX2 protein expression in 36 TAM-R and 36 TAM-S formalin-fixed paraffin-embedded (FFPE) breast tumor tissues. Data analysis indicated that PAX2 expression was significantly higher in TAM-S group in comparison to TAM-R (P = 0.014). Overexpression of PAX2 was significantly correlated with perineural invasion (PNI) (P = 0.025). Kaplan-Meier survival analysis showed significant association between high expression of PAX2 and better disease-free survival (P < 0.001) and also overall survival (P = 0.031). Multivariate cox regression analysis demonstrated that patients with increased expression of PAX2 have a trend toward improved disease free survival (OR = 0.065, 95% CI: 0.009-0.476; P = 0.007) and overall survival (OR = 0.147, 95% CI: 0.020-1.105; P = 0.062). Our data suggested that high expression of PAX2 could be associated with better survival in estrogen receptor positive tamoxifen-treated breast carcinoma patients.

Expression of HMG-Coareductase in Breast Carcinoma and its Association with Estrogen Receptor and Progesterone Receptor Status

Statins are the drugs that target 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCoAR). Several studies have reported the anti-tumoral properties of statins by exhibiting anti-proliferative properties in HMG-CoAR positive breast carcinomas. Increased efficacy has also been observed when these were used as combination therapy along with tamoxifen in estrogen receptor (ER) and HMG-COAR positive breast carcinomas. However, in our local population, expression of HMG-COAR is not investigated. The objective of our study was to examine the expression of HMG-CoAR in primary breast carcinomas and determine its association with ER/PR expression. Material &amp; Methods: Cross-sectional analytical study was conducted to examine the immunohistochemical expression of HMG-CoAR in 75 cases of breast carcinoma. Study was carried out in postgraduate medical institute, Lahore. The frequency and percentage were calculated for histological grade of the tumor and expression of HMG-CoAR, ER and PR. Fischer exact test was applied to determine the association between HMG-CoAR and ER/PR expression. Results: HMG CoAR, ER and PR were found positive in 69 (92%), 50 (66.67%) and 38 (50.67%) cases, respectively. HMG CoAR expression showed significant association with ER (p=0.003) as well as with PR (p= 0.014). Conclusion: Through results of our study, it is concluded that there is positive association between HMG CoAR and ER/PR statuses. Clinical trials are needed to establish the predictive role of HMG-CoAR expression as a target for statin therapy in breast carcinoma.

Altered DNA methyltransferases promoter methylation and mRNA expression are associated with tamoxifen response in breast tumors.

Tamoxifen is a standard anti-hormone treatment in estrogen receptor positive breast carcinoma patients. Unfortunately, about 50% of patients relapse during treatment. Promoter hypermethylation contributes to the epigenetic modulation of tamoxifen resistance-related genes. To evaluate the contribution of DNMTs expression and their promoter methylation as diagnostic biomarkers in development of breast malignancy and tamoxifen resistance, the present study was designed and 107 breast tumors and normal breast tissues were recruited. Methylation-specific high-resolution melt curve analysis and quantitative RT-PCR were performed to evaluate DNMTs promoter methylation and mRNA expression, respectively. Our results indicated that DNMT3A and DNMT3B promoters were demethylated in breast tumors as compared to control tissues. The mRNA expression levels of all three DNMTs were significantly increased in tumor specimens in comparison to control tissues (p < 0.05). Among tumor tissues, DNMT3A promoter methylation was significantly higher in tamoxifen sensitive patients (p = 0.001). Overexpression of DNMT3A (p = 0.037) and DNMT3B (p < 0.001) mRNA were observed in tamoxifen resistance group. Multivariate logistic regression analysis indicated that low methylation status of DNMT3A and overexpression of DNMT3B could be as independent predictors of disease recurrence. Multivariate Cox regression analysis, revealed that high methylation status of DNMT3A could be an independent and favorable predictor for disease free survival (p = 0.002) and overall survival (p = 0.026); high expression of DNMT1 (p = 0.03) remained significant and unfavorable predictive factor for overall survival. In conclusion, our data for the first time indicated that low methylation status of DNMT3A promoter and overexpression of DNMT3B could contribute to disease recurrence in tamoxifen-treated breast cancer patients.

Highlights from Recent Cancer Literature

Highlights from Recent Cancer Literature

Expression of oxysterol pathway genes in oestrogen-positive breast carcinomas.

This study investigated whether gene expression levels of key modulators of the oxysterol signalling pathway modify the prognosis of patients with oestrogen receptor-positive (ER+) breast carcinomas via interaction with endocrine therapy. The prognosis of patients with ER+ breast carcinoma depends on several factors. Previous studies have suggested that some oxygenated forms of cholesterol (oxysterols) bind to oestrogen receptor and anti-oestrogen binding site which may deregulate cholesterol homoeostasis and influence effect of therapy. The expression levels of 70 oxysterol pathway genes were evaluated in a test set of breast carcinomas differing in ER expression. The genes differentially expressed in ER+ tumours were assessed in a comprehensive set of ER+ tumours to evaluate their clinical significance. A total of 193 primary patients with breast carcinoma were included. The transcript levels were determined by quantitative real-time polymerase chain reaction. The expression levels of 23 genes were found to be specifically dysregulated in ER+ tumours compared to ER- tumours of the test set. The expression levels of ABCG2, CYP7B1, CYP24A1, CYP39A1 and CH25H genes were found to be strongly associated with disease stage; however, none of the gene expression levels were associated with disease-free survival in patients treated with endocrine therapy. The expression of a number of oxysterol pathway genes is significantly modulated by ER expression and associated with the clinical stage of patients. However, the expression of oxysterol pathway genes was not found to modify the prognosis of ER+ patients with breast carcinoma treated with endocrine therapy.

Non-canonical NF-κB pathway activation predicts outcome in borderline oestrogen receptor positive breast carcinoma.

Background:NF-κB signalling appears deregulated in breast tumours. The purpose of this study was to determine whether the non-canonical NF-κB pathway, is activated in oestrogen receptor positive (ER+) breast cancer, to identify any correlation between its activity and the clinico-pathological phenotype and to explore whether NF-κB2 and RelB subunits and/or any of their target genes might be used as a predictive marker.Methods:Two independent cohorts of ER+ early breast cancer patients treated with adjuvant endocrine therapy were included in the study. Activation of RelB and NF-κB2 subunits was determined in a training set of 121 patients by measuring DNA-binding activities in nuclear extracts from fresh frozen specimens by an ELISA-based assay. Samples of 15 ER− breast cancer patients were also included in the study. In a large validation cohort of 207 patients, nuclear immunostaining of RelB and NF-κB2 on formalin-fixed paraffin-embedded specimens was performed. Statistical correlation within clinico-pathological factors, disease-free survival (DFS) and overall survival (OS) was evaluated. Publicly available gene expression and survival data have been interrogated aimed to identify target genes.Results:Activation of NF-κB2 and RelB was found in 53.7 and 49.2% of the 121 ER+ tumours analysed, with similar levels to ER− breast tumours analysed in parallel for comparisons. In the validation cohort, we obtained a similar proportion of cases with activation of NF-κB2 and RelB (59.9 and 32.4%), with a 39.6% of co-activation. Multiplexing immunofluorescence in breast cancer tissue confirmed an inverse spatial distribution of ER with NF-κB2 and RelB nuclear expression in tumour cells. Interestingly, NF-κB2 and RelB mRNA expression was inversely correlated with ER gene (ESR1) levels (P<0.001, both) and its activation was significantly associated with worse DFS (P=0.005 and P=0.035, respectively) in ER+ breast cancer. Moreover, the co-activation of both subunits showed a stronger association with early relapse (P=0.002) and OS (P=0.001). Finally, higher expression of the non-canonical NF-κB target gene myoglobin was associated with a poor outcome in ER+ breast cancer (DFS, P<0.05).Conclusions:The non-canonical NF-κB pathway activation is inversely associated with oestrogen receptor expression in ER+ breast cancer and predicts poor survival in this subgroup. The myoglobin gene expression has been identified as a possible surrogate marker of the non-canonical NF-κB pathway activation in these tumours.

Correlative Analysis of miRNA Expression and Oncotype Dx Recurrence Score in Estrogen Receptor Positive Breast Carcinomas.

Altered expression of miRNAs has been observed in many types of cancer, including breast cancer, and shown to contribute to cancer growth, aggressiveness, and response to therapies. In this pilot study, we investigated the possible correlation of miRNAs with risk of recurrence of estrogen receptor positive, lymph node-negative mammary carcinomas as determined by the Oncotype DX® Breast Cancer assay. To accomplish this, we extracted RNA from a collection of breast carcinomas that had previously been analyzed by Oncotype DX®. Multiple Let-7 family members were negatively correlated with the recurrence score (RS), which is consistent with their tumor suppressor properties. Additional miRNAs were found to positively correlate with RS, including miR-377-5p, miR-633b, miR-548t and miR-3648. Pathway analysis of putative and validated targets suggests that these miRNAs may have a diverse range of functions that may contribute to tumor recurrence. Taken together, these findings provide evidence that a miRNA expression signature can be developed to aid existing methods to determine the risk of recurrence for women with estrogen receptor positive breast cancers treated with endocrine therapy.

GATA-3 and FOXA1 expression is useful to differentiate breast carcinoma from other carcinomas

GATA-3, a member of the GATA family of zinc-finger DNA binding proteins, and FOXA1, a member of the forkhead transcription factor family, are both associated with estrogen receptor expression. Both GATA-3 and FOXA1 are useful markers for breast carcinoma, but their expression in the different breast cancer subtypes and other neoplasms has not been thoroughly evaluated. We examined the expression of GATA-3 and FOXA1 in estrogen receptor-positive, Her2/neu-positive, and triple-negative breast carcinomas as well as in 10 other common carcinomas, including hepatocellular, colonic, pancreatic, gastric, endometrial (endometrioid), lung, prostatic, renal cell, urothelial, and ovarian serous carcinomas. Primary and metastatic melanomas and mesotheliomas were also evaluated. GATA-3 and FOXA1 staining of estrogen receptor-positive breast carcinomas was seen in 96.6% and 96.2%, respectively. In triple-negative breast carcinomas, GATA-3 and FOXA1 staining was seen in 21.6% and 15.9%, respectively. Among the other tumors, GATA-3 staining was only seen in urothelial carcinoma (70.9%) and FOXA1 staining was only seen in prostatic (87.5%), urothelial (5.1%) carcinomas, and mesotheliomas (40.0%). In conclusion, GATA-3 and FOXA1 are excellent breast carcinoma markers; however, their utility is limited in the triple-negative subtype. The utility of FOXA1 in diagnosing prostatic carcinoma and mesothelioma warrants further investigation.

Back to Basics: Traditional Nottingham Grade Mitotic Counts Alone are Significant in Predicting Survival in Invasive Breast Carcinoma.

Newer multigene molecular profiling assays for breast carcinoma rely heavily on the quantification of genes of proliferation, whereas traditional histological grading reports the mitotic count. The mitotic activity of invasive breast carcinomas may be undervalued; therefore, an evaluation of the prognostic significance of mitotic score in predicting prognosis was performed. Retrospective analysis of a single institutional cohort of newly diagnosed estrogen receptor positive (ER+), HER2 negative (HER2-) unilateral invasive breast carcinomas was performed. Mitotic scores from the 3-part Nottingham combined histological grade were compared with clinical parameters. Mitoses were counted on Olympus BX50 microscopes and assigned scores of 1-3 based on observed mitoses. A total of 1292 ER+, HER2- invasive breast carcinoma patients were identified, with a median follow-up time of 2.6 years (range 0-14 years). Higher mitotic score was significantly associated with younger age, larger tumor size, angiolymphatic invasion, node-positive disease, higher stage, and the use of hormonal and cytotoxic chemotherapy. Mitotic score was significant in modeling time to local/regional recurrence (p = 0.02), recurrence-free survival/RFS (p < 0.001), and overall survival/OS (p = 0.01) with higher mitotic scores associated with worse outcomes. Higher mitotic score correlated significantly with intermediate/high risk Oncotype Dx recurrence scores (p = 0.009). First-generation molecular profiling assays for estrogen receptor positive invasive breast carcinomas derive much of their predictive power from quantifying genes of proliferation into a single score. Sometimes overlooked in the profusion of molecular data, the time-tested, mitotic count in the Nottingham combined histological grade is a good single-parameter predictor of survival.

Immunolocalization of thymidylate synthase as a favorable prognostic marker in estrogen receptor-positive breast carcinoma.

Thymidylate synthase (TS) is an enzyme involved in DNA synthesis, and it is a target for 5-fluorouracil. Previous studies have demonstrated that TS is a potent estrogen-induced gene in breast carcinoma cells, suggesting the importance of TS in estrogen-receptor (ER)-positive breast carcinoma. TS immunolocalization has been reported previously, but the clinicopathological significance of TS in ER-positive breast carcinoma still remains unclear. We immunolocalized TS in 178 breast carcinoma tissues in total, and examined its significance according to the ER-status. TS status was positive in 58% of ER-positive ductal carcinoma in situ (DCIS) cases, and it was significantly associated with the Ki-67 and progesterone receptor (PR). Moreover, in ER-positive DCIS patients who received aromatase inhibitor (AI) before surgery, TS immunoreactivity was significantly decreased after AI treatment. In ER-positive invasive ductal carcinoma (IDC) cases, TS status was significantly associated with PR, and it turned out an independent favorable prognostic factor for recurrence of the patients by multivariate analysis. On the other hand, TS status was positively correlated with pathological T factor in ER-negative IDC cases, and tended to have a worse prognosis for disease-free survival of the patients. These results suggest that TS expression is mainly regulated by estrogen in ER-positive breast carcinoma and is associated with estrogen-mediated proliferation. TS status is a favorable prognostic factor in ER-positive IDC patients, which is different from the ER-negative cases.

Correlation between activation of PI3K/AKT/mTOR pathway and prognosis of breast cancer in Chinese women.

BackgroundAbnormal activation of PI3K/AKT/mTOR (PAM) pathway, caused by PIK3CA mutation, KRAS mutation, PTEN loss, or AKT1 mutation, is one of the most frequent signaling abnormalities in breast carcinoma. However, distribution and frequencies of mutations in PAM pathway are unclear in breast cancer patients from the mainland of China and the correlation between these mutations and breast cancer outcome remains to be identified.MethodsA total of 288 patients with invasive ductal breast cancer were recruited in this study. Mutations in PIK3CA (exons 4, 9 and 20), KRAS (exon 2) and AKT1 (exon 3) were detected using Sanger sequencing. PTEN loss was measured by immunohistochemistry assay. Correlations between these genetic aberrations and clinicopathological features were analyzed.ResultsThe frequencies of PIK3CA mutation, KRAS mutation, AKT1 mutation and PTEN loss were 15.6%, 1.8%, 4.4% and 35.3%, respectively. However, except for PTEN loss, which was tied to estrogen receptor (ER) status, these alterations were not associated with other clinicopathological features. Survival analysis demonstrated that PIK3CA mutation, PTEN loss and PAM pathway activation were not associated with disease-free survival (DFS). Subgroup analysis of patients with ER positive tumors revealed that PIK3CA mutation more strongly reduced DFS compared to wild-type PIK3CA (76.2% vs. 54.2%; P = 0.011). PIK3CA mutation was also an independent factor for bad prognosis in ER positive patients.Conclusions AKT1, KRAS and PIK3CA mutations and PTEN loss all exist in women with breast cancer in the mainland China. PIK3CA mutation may contribute to the poor outcome of ER positive breast carcinomas, providing evidence for the combination of PI3K/AKT/mTOR inhibitors and endocrine therapy.

Oxidative Stress-Mediated Apoptosis Induced by Ethanolic Mango Seed Extract in Cultured Estrogen Receptor Positive Breast Cancer MCF-7 Cells

Breast cancer has become a global health issue requiring huge expenditures for care and treatment of patients. There is a need to discover newer cost-effective alternatives for current therapeutic regimes. Mango kernel is a waste product with potential as a source of anti-cancer phytochemicals, especially since it is non-toxic towards normal breast cell lines at concentrations for which it induces cell death in breast cancer cells. In this study, the anti-cancer effect of mango kernel extract was determined on estrogen receptor-positive human breast carcinoma (MCF-7) cells. The MCF-7 cells were cultured and treated with 5, 10 and 50 μg/mL of mango kernel extract for 12 and 24 h. In response to treatment, there were time- and dose-dependent increases in oxidative stress markers and pro-apoptotic factors; Bcl-2-like protein 4 (BAX), p53, cytochrome c and caspases (7, 8 and 9) in the MCF-7 cells treated with the extract. At the same time, there were decreases in pro-survival markers (Bcl-2 and glutathione) as the result of the treatments. The changes induced in the MCF-7 cells by mango kernel extract treatment suggest that the extract can induce cancer cell apoptosis, likely via the activation of oxidative stress. These findings need to be evaluated further to determine whether mango kernel extract can be developed as an anti-breast cancer agent.

A Case of Docetaxel Induced Myositis and Review of the Literature.

In phase I and II trials taxane chemotherapeutic agents reported side effects, including myelosuppression, peripheral edema, and fluid retention. With further use of these agents, studies in the late 1980s and early 1990s began to report peripheral neuropathy and proximal muscle weakness as common complaints, the later with unexplained pathophysiology. We report a 65-year-old Hispanic woman with estrogen receptor (ER) and progesterone receptor (PR) positive invasive ductal breast carcinoma who presented with right thigh pain and swelling eight days after her third infusion of docetaxel (a taxane chemotherapeutic) and cyclophosphamide. Laboratory findings were notable for elevation in creatine phosphokinase (CPK), aldolase, and erythrocyte sedimentation rate (ESR); a magnetic resonance imaging (MRI) of her lower extremities showed evidence of bilateral muscle edema involving the anterior compartment muscles of the thighs. A workup to rule out other causes of myositis was negative. Docetaxel was not reintroduced and the patient improved with corticosteroids. Since 2005 this is, to our knowledge, the fifth reported case of docetaxel related inflammatory myositis. Taxanes have been noted to cause disabling but transient arthralgias and myalgias; it is important to consider the possibility of inflammatory myopathy as a possible complication in patients undergoing treatment with these agents.

E15. HER2 assessment in breast cancer

Because of the important therapeutic implications, a crucial issue in breast cancer pathology is the correct identification of true HER2 positivity in tissue specimens. The relevance of such assessment on HER2-positive breast cancer patients will be further enhanced if trastuzumab is administered to patients in monotherapy, such as trastuzumab emtansine (i.e. trastuzumab-DM1, T-DM1), an antibody–drug conjugate consisting of trastuzumab linked to the cytotoxin mertansine (DM1). T-DM1 is designed to target and inhibit HER2 signaling and to deliver the chemotherapy directly inside HER2-positive cancer cells. As a consequence, it will be of utmost importance for pathologists to recognize HER2-positive carcinomas with precision, because patients will not be administered any other chemotherapeutic agents and response to treatment will rely strictly on the pathological assessment of HER2 [1]. Activation of HER2 may be driven not only by HER2 gene amplification; indeed, in terms of the biology of HER2-positive tumors, a “brand new” topic is the recent demonstration by next-generation sequencing studies of the presence of HER2 mutations in breast cancer [2]. Bose and colleagues [3] have functionally characterized 13 HER2 mutations, and seven of these mutations were activating mutations sensitive to the irreversible HER2/EGFR tyrosine kinase inhibitor neratinib [3]. Estrogen-receptor(ER-)positive breast carcinomas, either HER2-negative (score 0/1+) or showing equivocal HER2 expression (score 2+), seem to be putative candidates for HER2 mutations. Here we discuss some of the “hot topics” concerning HER2 assessment.

Chemopreventive activity of Cnidii Rhizoma for breast cancer

Chemopreventive potential for human breast cancer was assessed in vitro with Cnidii Rhizoma extract. Cnidii Rhizoma inhibited cell proliferation in estrogen receptor-positive (MCF-7) and estrogen receptor-negative (MDA-MB-231) human breast carcinoma cell lines. Cytochrome P450 (CYP) 1A1-mediated ethoxyresorufin O-deethylase (EROD) activity was inhibited by Cnidii Rhizoma in a concentration-dependent manner. In addition, Cnidii Rhizoma extract caused inhibition of microsomal aromatase (estrogen synthase) activity. Ornithine decarboxylase (ODC) activity was reduced to 40.3% of the control after 6 h treatment with Cnidii Rhizoma (5 mg/mL) in MCF-7 breast cancer cells. Cnidii Rhizoma extract markedly reduced 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated matrix metalloproteinase (MMP)-9 activity. These results suggest that Cnidii Rhizoma could be of therapeutic value in preventing human breast cancer.

Tumour grade on core biopsy and evidence of axillary involvement on ultrasound predicts response in elderly co-morbid patients treated with primary hormone therapy for oestrogen receptor positive breast carcinoma

IntroductionTreatment of women with oestrogen-receptor positive breast cancer who are high risk for general anaesthetic remains controversial. Current guidance is based on studies pre-dating aromatase inhibitors (AIs) which may have also included hormone-receptor negative patients. Such studies have demonstrated improved disease-free survival and local disease control following surgery when compared with primary hormone therapy (PHT) alone. However uncertainty persists regarding benefit of surgery over optimal hormone treatment in patients with significant co-morbidity. MethodRetrospective cohort study comparing efficacy of PHT in oestrogen-receptor positive breast cancer patients considered unsuitable for surgery. Co-morbidity was scored retrospectively using the Charlson Index. Overall survival and disease specific survival were noted and multivariate analysis performed to identify predictors of treatment failure. Results106 patients treated for breast cancer at Southampton University Hospital with PHT without surgery were identified (Mean age 84.1 years, range 48–101). 94.3% had a probability of 10 year survival of 2.25% or less according to the age-weighted Charlson score. Kaplan–Meier analysis demonstrated a four-year survival of 30% and breast cancer specific survival of 60%. Cox proportional hazards model demonstrated high-grade disease (grade III vs. grade I/II: HR = 2.007; 95% Confidence Interval (CI) = 1.004–4.014. P = 0.049) and ultrasound axillary staging (indeterminate/definite lymphatic involvement vs. no involvement: HR = 1.944; 95% CI = 1.010–3.742. P = 0.047) independently predicted early failure of PHT. ConclusionA high proportion of elderly and comorbid patients die with breast cancer rather than from breast cancer. Elderly comorbid patients who initially respond to primary hormone therapy have a less than 30% incidence of delayed treatment failure during their life time; however patients with grade III disease or an abnormal axillary ultrasound are twice as likely to fail first choice PHT.

Abstract P5-09-15: Polymorphism of the CYP2D6 gene in Brazilian women with breast cancer treated with tamoxifen

Abstract The prodrug tamoxifen is the standard endocrine treatment for estrogen receptor-positive breast cancer. Its effect depends on activation by the CYP2D6 enzyme, which is encoded by a highly polymorphic gene that varies according to ethnicity. The most important polymorphic variants are *4 (abolished enzyme activity), *10 and *17 (decreased enzyme activity) found in 25%, 38-70% and 35% of Caucasians, Asians and Africans, respectively, resulting in low endoxifen levels (a major metabolite), a lack of response to tamoxifen and a poor prognosis. There is a widespread racial miscegenation in Brazil and the country's public health care system has made tamoxifen available and free of charge to all women with hormone-sensitive breast tumor despite the undetermined genetic profile of these patients.This study aims to evaluate polymorphism frequency of the CYP2D6*4, *10 and *17 alleles in Brazilian breast cancer patients under tamoxifen treatment and metabolism phenotype. Methods: The study was approved by the Internal Review Board of the Federal University of Piauí. All patients signed an informed consent term before study entry. Sixty-five women with estrogen and progesterone receptor-positive and Her-2 negative breast carcinomas were enrolled in the study. A 3-ml peripheral blood sample was collected from each patient, using specific polymerase chain reaction technique (PCR) to analyze haplotypes *1, *4, *10 and *17, determined by studies of different Single-Nucleotide Polymorphism (SNP). Microsoft Office Excel software 2010 was used to compile and analyze the data obtained. Results: The frequency of CYP2D6 alleles *4, *10 and *17 was 17%, 37% and 3%, respectively. Haplotype *1/*10 was present in 26%, while the phenotype of intermediate metabolism occurred in 12% of the women studied. Conclusion: The present study showed a polymorphism frequency of CYP2D6, mainly of allele *10 and a deficiency in tamoxifen metabolism, characterized by intermediate metabolism in 12% of the women studied. Nevertheless, further studies must be developed with a larger sample of women to study not only the presence of the polymorphic variant but also disease prognosis. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-09-15.

Comparison of Oncotype DX and Mammostrat risk estimations and correlations with histologic tumor features in low-grade, estrogen receptor-positive invasive breast carcinomas

Several molecular tests have been developed to estimate risk of distant recurrence and help clinical decision-making regarding adjuvant chemotherapy in patients with early stage breast carcinoma. Both Oncotype DX, a 21-gene expression profile, and Mammostrat, an immunohistochemistry-based assay, are validated to stratify patients into groups with low, intermediate and high risk of distant recurrence. However, they have not been compared head-to-head and little data are available regarding their correlation with clinicopathologic tumor features. In this study, we compared the clinicopathologic tumor features with risk estimations by Oncotype DX and Mammostrat in 106 low-grade estrogen receptor (ER)-positive breast carcinomas. Double immunohistochemical stain for pancytokeratin and Ki-67 was performed to assess cell proliferation in cancer vs stromal/inflammatory cells. Tumors showing intermediate/high risk by Oncotype DX, but not by Mammostrat, showed increased stromal cellularity, presence of inflammatory cells and increased proliferation in stromal/inflammatory cells. Discrepant cases showing intermediate/high risk by Oncotype DX but low risk by Mammostrat were associated with increased stromal cellularity, presence of inflammatory cells and increased proliferation in stromal/inflammatory cells, compared with concordant cases showing low risk by both assays. Our results suggest that low-grade ER-positive breast carcinomas with increased stromal/inflammatory cell proliferation may show an apparent increased risk of distant recurrence as assessed by Oncotype DX, which uses RNA extracted from a mixture of tumor and stromal/inflammatory cells in the assay. Mammostrat, which examines cancer cells only, may provide a better estimation of likely tumor behavior in a subgroup of low-grade breast carcinomas.