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Schiff R, Osborne CK. Endocrinology and hormone therapy in breast cancer: new insight into estrogen receptor-alpha function and its implication for endocrine therapy resistance in breast cancer. Breast Cancer Res 2005; 7:205-11. [PMID: 16168139 PMCID: PMC1242145 DOI: 10.1186/bcr1287] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Estrogen and its receptor (ER) are critical for development and progression of breast cancer. This pathway is targeted by endocrine therapies that either block ER functions or deplete ER's estrogen ligand. While endocrine therapies are very effective, de novo and acquired resistance are still common. Laboratory and clinical data now indicate that bidirectional molecular crosstalk between nuclear or membrane ER and growth factor receptor pathways such as HER2/neu is involved in endocrine resistance. Preclinical data suggest that blockade of selected growth factor receptor signaling can overcome this type of resistance, and this strategy is already being tested in clinical trials
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Dowsett M, Johnston S, Martin LA, Salter J, Hills M, Detre S, Gutierrez MC, Mohsin SK, Shou J, Allred DC, Schiff R, Osborne CK, Smith I. Growth factor signalling and response to endocrine therapy: the Royal Marsden Experience. Endocr Relat Cancer 2005; 12 Suppl 1:S113-7. [PMID: 16113087 DOI: 10.1677/erc.1.01044] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
De novo resistance to endocrine therapy is a near-universal feature of oestrogen receptor (ER)- negative breast cancer. Although many ER-positive breast cancers also show no response to tamoxifen or aromatase inhibitors on objective clinical grounds the large majority show reduced proliferation indicating that some oestrogen dependence is present in almost all ER-positive breast cancer. In neoadjuvant studies HER2 positivity is associated with poor response rates to tamoxifen but not aromatase inhibitors, consistent with preclinical models. Acquired resistance to tamoxifen is associated with decreases in ER positivity but most recurrent lesions remain ER-positive. A small proportion of these show increased HER2 expression and in these patients increased phospho-p38 may contribute to the tamoxifen-resistant phenotype. There is an unfortunate paucity of clinical and biological data on acquired resistance to aromatase inhibitors.
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Hopp TA, Weiss HL, Parra IS, Cui Y, Osborne CK, Fuqua SAW. Low levels of estrogen receptor beta protein predict resistance to tamoxifen therapy in breast cancer. Clin Cancer Res 2005; 10:7490-9. [PMID: 15569979 DOI: 10.1158/1078-0432.ccr-04-1114] [Citation(s) in RCA: 152] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Breast cancer is a hormone-dependent cancer, and the presence of estrogen receptor alpha (ER-alpha) in tumors is used clinically to predict the likelihood of response to hormonal therapies. The clinical value of the second recently identified ER isoform, called ER-beta, is less clear, and there is currently conflicting data concerning its potential role as a prognostic or predictive factor. EXPERIMENTAL DESIGN To assess whether ER-beta expression is associated with clinical outcome, protein levels were measured by immunoblot analysis of a retrospective bank of tumor cell lysates from 305 axillary node-positive patients. A total of 119 received no adjuvant therapy, and 186 were treated with tamoxifen only. The median follow-up time was 65 months. Univariate and multivariate Cox regression modeling was done to assess the prognostic and predictive significance of ER-beta expression. RESULTS Expression of ER-beta protein did not correlate significantly with any other clinical variables, including ER and progesterone levels (as measured ligand binding assay), tumor size, age, or axillary nodal status. In the untreated population, those patients whose tumors who expressed both receptor isoforms exhibited the most favorable outcome as compared with those patients who had lost ER-alpha expression. However, there was no association between ER-beta levels alone and either disease-free or overall survival in the untreated patient population. In contrast, in both univariate and multivariate analyses, high levels of ER-beta predicted an improved disease-free and overall survival in patients treated with adjuvant tamoxifen therapy. CONCLUSIONS These findings provide evidence that ER-beta may be an independent predictor of response to tamoxifen in breast cancer. Furthermore, these results suggest that ER-beta may influence tumor progression in ways different from those mediated by the ER-alpha isoform.
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Abstract
Estrogen and its cognate estrogen receptor are key players in the etiology and progression of breast cancer. Aromatase inhibitors, suppressing tumor and plasma estrogen levels by blocking testosterone conversion to estrogen, have been proven to provide the most effective endocrine therapy for postmenopausal breast cancer patients. Aromatase inhibitors are now the first choice endocrine therapy in the metastatic setting for postmenopausal women. These endocrine agents also seem likely to soon become the standard adjuvant therapy, either alone or in sequence with tamoxifen, though their long-term toxicity and the optimum duration of therapy still remain to be defined. Advanced experimental studies and some clinical observations reveal the importance of blocking both the genomic and non-genomic activities of the estrogen receptor, as well as its crosstalk with growth factor and other cellular signaling, for greatest effectiveness of endocrine therapy. Consequently, these studies provide a mechanistic explanation for the superb performance of aromatase inhibitors, and also suggest how inhibiting selected growth factor receptors might delay or prevent the onset of resistance to aromatase inhibitors and other endocrine therapies.
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205
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Arpino G, Weiss HL, Clark GM, Hilsenbeck SG, Osborne CK. Hormone receptor status of a contralateral breast cancer is independent of the receptor status of the first primary in patients not receiving adjuvant tamoxifen. J Clin Oncol 2005; 23:4687-94. [PMID: 15837971 DOI: 10.1200/jco.2005.04.076] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE To determine whether the hormone receptor status of the primary breast cancer (PBC) is predictive of the hormone receptor status of the subsequent contralateral breast cancer (CBC). PATIENTS AND METHODS We identified patients in our database with known estrogen receptor (ER; n = 193) and/or progesterone receptor (PgR; n = 178) status in their PBC and in their subsequent CBC. One hundred twenty-six of these patients had received no adjuvant therapy, 34 had received adjuvant tamoxifen, and 33 had received adjuvant chemotherapy alone. The median interval between the first diagnosis of PBC and the development of the subsequent CBC was 3 years. ER and PgR assays were assessed biochemically in two central reference laboratories using identical quality-controlled ligand-binding methods. RESULTS Among systemically untreated patients (n = 126), 88% of patients with ER-positive PBC and 75% of patients with ER-negative PBC developed an ER-positive CBC (P = .11). Among the tamoxifen-treated patients, those with an ER-positive PBC were almost equally likely to develop an ER-positive (47%) or ER-negative (53%) CBC (P = .99). PgR status was similar. In the untreated group (n = 112), 59% of patients with a PgR-positive PBC and 66% with a PgR-negative PBC developed a PgR-positive CBC (P = .48). Among tamoxifen-treated patients (n = 33), 50% of patients with a PgR-positive PBC versus 27% of patients with a PgR-negative PBC developed a PgR-positive CBC (P = .28). CONCLUSION ER and PgR status of the primary tumor does not predict the hormone receptor status of the subsequent CBC in the absence of selective pressure of adjuvant therapy. Thus, other reasons should be considered to clarify the failure of tamoxifen to reduce the incidence of CBC in patients with a receptor-negative PBC.
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206
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Mohsin SK, Weiss HL, Gutierrez MC, Chamness GC, Schiff R, Digiovanna MP, Wang CX, Hilsenbeck SG, Osborne CK, Allred DC, Elledge R, Chang JC. Neoadjuvant Trastuzumab Induces Apoptosis in Primary Breast Cancers. J Clin Oncol 2005; 23:2460-8. [PMID: 15710948 DOI: 10.1200/jco.2005.00.661] [Citation(s) in RCA: 200] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Purpose Greater understanding of the cellular response in trastuzumab-treated patients will provide insight into the clinical management of patients. Patients and Methods We performed a neoadjuvant trial in 35 patients with locally advanced HER-2/neu overexpressing breast cancers who received weekly trastuzumab given as a single agent for the first 3 weeks, followed by a combination of trastuzumab and docetaxel for 12 weeks before surgery. Sequential core biopsies were taken at baseline and within weeks 1 and 3 after the first dose of trastuzumab. Clinical response to trastuzumab was assessed by tumor measurements on day 22 before chemotherapy. Core biopsies were assessed by immunohistochemistry for cell cycle and proliferation (Ki67, p27, phosphorylated [p] -MAPK), apoptosis and survival (apoptotic index, p-Akt), epidermal growth factor receptor, and total and p-HER-2. Results There was early tumor regression with a median decrease of −20.0% (range. 0% to 60.4%) after only 3 weeks of trastuzumab, and eight patients (23%) had a partial response. Consistent with the clinical regressions, apoptosis was significantly induced (median increase from 3.5% to 4.7%; P = .006) within week 1, a 35% increase above baseline. No significant change in epidermal growth factor receptor score was observed in week 1, without changes in total or p-HER-2 expression. Tumors with high baseline Ki67 were less likely to respond (P = .02). Conclusion In primary breast cancers, trastuzumab substantially induces apoptosis, providing a molecular explanation for both its therapeutic efficacy and its successful combination with cytotoxic chemotherapy.
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207
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Osborne CK, Schiff R. Estrogen-receptor biology: continuing progress and therapeutic implications. J Clin Oncol 2005; 23:1616-22. [PMID: 15755967 DOI: 10.1200/jco.2005.10.036] [Citation(s) in RCA: 246] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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208
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Chang JC, Wooten EC, Tsimelzon A, Hilsenbeck SG, Gutierrez MC, Tham YL, Kalidas M, Elledge R, Mohsin S, Osborne CK, Chamness GC, Allred DC, Lewis MT, Wong H, O'Connell P. Patterns of resistance and incomplete response to docetaxel by gene expression profiling in breast cancer patients. J Clin Oncol 2005; 23:1169-77. [PMID: 15718313 DOI: 10.1200/jco.2005.03.156] [Citation(s) in RCA: 144] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE Chemotherapy for operable breast cancer decreases the risk of death. Docetaxel is one of the most active agents in breast cancer, but resistance or incomplete response is frequent. PATIENTS AND METHODS Core biopsies from 24 patients were obtained before treatment with neoadjuvant docetaxel (four cycles, 100 mg/m(2) every 3 weeks), and response was assessed after chemotherapy. After 3 months of neoadjuvant chemotherapy, surgical specimens (n = 13) were obtained, and laser capture microdissection (LCM; n = 8) was performed to enrich for tumor cells. From each core, surgical, and LCM specimen, sufficient total RNA (3 to 6 microg) was extracted for cDNA array analysis using the Affymetrix HgU95-Av2 GeneChip (Affymetrix, Santa Clara, CA). RESULTS From the initial core biopsies, differential patterns of expression of 92 genes correlated with docetaxel response (P = .001). However, the molecular patterns of the residual cancers after 3 months of docetaxel treatment were strikingly similar, independent of initial sensitivity or resistance. This relative genetic homogeneity after treatment was observed in both LCM and non-LCM surgical specimens. The residual tumor after treatment in tumors that were initially sensitive indicates selection of a residual and resistant subpopulation of cells. The gene expression pattern was populated by genes involved in cell cycle arrest at G(2)M (eg, mitotic cyclins and cdc2) and survival pathways involving the mammalian target of rapamycin. CONCLUSION A specific and consistent gene expression pattern was found in residual tumors after docetaxel treatment. These profiles provide therapeutic targets that could lead to improved treatment.
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209
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Gutierrez MC, Detre S, Johnston S, Mohsin SK, Shou J, Allred DC, Schiff R, Osborne CK, Dowsett M. Molecular changes in tamoxifen-resistant breast cancer: relationship between estrogen receptor, HER-2, and p38 mitogen-activated protein kinase. J Clin Oncol 2005; 23:2469-76. [PMID: 15753463 DOI: 10.1200/jco.2005.01.172] [Citation(s) in RCA: 344] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
PURPOSE To evaluate growth factor receptor cross talk with the estrogen receptor (ER) in paired clinical breast cancer specimens and in a xenograft model before tamoxifen and at tumor progression as a possible mechanism for tamoxifen resistance. METHODS Specimen pairs from 39 patients were tissue arrayed and stained for ER, progesterone receptor (PgR), Bcl-2, c-ErbB2 (HER-2), and phosphorylated (p) p38 mitogen-activated protein kinase (MAPK), p-ERK1/2 MAPK, and p-Akt. Xenograft MCF-7 tumors before and after tamoxifen resistance were assessed for levels of p-p38. RESULTS Pretreatment, there were strong correlations between ER, PgR, and Bcl-2, and an inverse correlation between ER and HER-2. These correlations were lost in the tamoxifen- resistant tumors and replaced by strong correlations between ER and p-p38 and p-ERK. ER expression was lost in 17% of resistant tumors. Three (11%) of the 26 tumors originally negative for HER-2 became amplified and/or overexpressed at resistance. All ER-positive tumors that overexpressed HER-2 originally or at resistance expressed high levels of p-p38. In the pretreatment and tamoxifen-resistant specimens, there were strong correlations between p-p38 and p-ERK. In the tamoxifen-resistant xenograft tumors, like the clinical samples, there was a striking increase in p-p38. CONCLUSION The molecular pathways driving tumor growth can change as the tumor progresses. Crosstalk between ER, HER-2, p38, and ERK may contribute to tamoxifen resistance and may provide molecular targets to overcome this resistance.
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MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Animals
- Antineoplastic Agents, Hormonal/administration & dosage
- Antineoplastic Agents, Hormonal/pharmacology
- Antineoplastic Agents, Hormonal/therapeutic use
- Biopsy
- Breast Neoplasms/drug therapy
- Breast Neoplasms/physiopathology
- Chemotherapy, Adjuvant
- Disease Progression
- Drug Resistance, Neoplasm
- Female
- Humans
- Immunohistochemistry
- Mice
- Mice, Nude
- Middle Aged
- Receptor, ErbB-2/physiology
- Receptors, Estrogen/drug effects
- Receptors, Estrogen/physiology
- Signal Transduction
- Tamoxifen/administration & dosage
- Tamoxifen/pharmacology
- Tamoxifen/therapeutic use
- Transplantation, Heterologous
- p38 Mitogen-Activated Protein Kinases/pharmacology
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210
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Fuqua SAW, Cui Y, Lee AV, Osborne CK, Horwitz KB. Insights into the role of progesterone receptors in breast cancer. J Clin Oncol 2005; 23:931-2; author reply 932-3. [PMID: 15681552 DOI: 10.1200/jco.2005.05.152] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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211
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Lippman ME, Benz C, Chinnaiyan A, Flockhart D, Harris A, Hudis C, Osborne CK, Press MF, Rae J, Sledge GW, Van't Veer L, Wicha M. Consensus statement: Expedition Inspiration 2004 Breast Cancer Symposium ?Breast Cancer ? the Development and Validation of New Therapeutics? Breast Cancer Res Treat 2005; 90:1-3. [PMID: 15770520 DOI: 10.1007/s10549-004-1288-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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212
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Arpino G, Green SJ, Allred DC, Lew D, Martino S, Osborne CK, Elledge RM. HER-2 amplification, HER-1 expression, and tamoxifen response in estrogen receptor-positive metastatic breast cancer: a southwest oncology group study. Clin Cancer Res 2005; 10:5670-6. [PMID: 15355892 DOI: 10.1158/1078-0432.ccr-04-0110] [Citation(s) in RCA: 186] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE Preclinical data indicate that expression of the ErbB family of receptors, such as HER-2 and HER-1 (EGFR) may be involved in endocrine resistance. Evidence of resistance from clinical studies has been inconsistent. The present study examined whether HER-2 gene amplification or HER-1 expression predicted response to tamoxifen. PATIENTS AND METHODS Three hundred and forty nine patients had estrogen receptor (ER)-positive breast cancer and received daily tamoxifen as initial therapy for advanced disease. HER-2 gene amplification, detected by fluorescence in situ hybridization, and HER-1 expression, evaluated by immunohistochemistry, was determined on 136 and 204 patients, respectively. RESULTS HER-2 amplification was correlated with lower ER (P = 0.02), HER-1 positivity (P = 0.004), and HER-2 protein overexpression (P < 0.00001). The response rate was 56% for HER-2 non-amplified versus 47% for HER-2 amplified tumors (P = 0.38), and 58% for HER-1-negative versus 36% for HER-1-positive (P = 0.05). Time to treatment failure (TTF) was 7 months for non-amplified HER-2 tumors and 5 months (P = 0.007) for amplified HER-2 tumors, and there was a trend toward a better overall survival (OS) in patients with non-amplified HER-2 tumors (median 31 versus 25 months, respectively, P = 0.07). For positive versus negative HER-1 tumors, TTF was 4 versus 8 months (P = 0.08) and median survival was 24 versus 31 months (P = 0.41). Combining HER-1 expression and HER-2 gene status, patients with both negative HER-1 expression and non-amplified HER-2 had longer TTF (P = 0.001) and OS (P = 0.03) than if either were positive. In multivariate analysis, HER-2 was not an independent factor for TTF and OS, although HER-1 was significant for TTF only (P </= 0.001). CONCLUSION Patients with HER-2 amplification and HER-1 expression had lower ER levels and were modestly less responsive to tamoxifen, suggesting that molecular events in addition to those involving the ErbB receptors are important in determining the endocrine-resistant phenotype.
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213
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Osborne CK, Shou J, Massarweh S, Schiff R. Crosstalk between estrogen receptor and growth factor receptor pathways as a cause for endocrine therapy resistance in breast cancer. Clin Cancer Res 2005; 11:865s-70s. [PMID: 15701879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Data suggest that breast cancer growth is regulated by coordinated actions of the estrogen receptor (ER) and various growth factor receptor signaling pathways. In tumors with active growth factor receptor signaling (e.g., HER2 amplification), tamoxifen may lose its estrogen antagonist activity and may acquire more agonist-like activity, resulting in tumor growth stimulation. Because treatments designed to deprive the ER of its ligand estrogen will reduce signaling from both nuclear and membrane ER, aromatase inhibitors might be expected to be superior to tamoxifen in tumors with high growth factor receptor content, such as those overexpressing HER2. Recent clinical studies suggest that this is the case in humans, as trials of aromatase inhibitors show superior results compared with tamoxifen, especially in tumors overexpressing HER2. Although estrogen deprivation therapy is often effective in ER-positive breast cancer, de novo and acquired resistance are still problematic. Experimental models suggest that in one form of resistance to estrogen deprivation therapy, the tumor becomes supersensitive to low residual estrogen concentrations perhaps because of activation of mitogen-activated protein kinase. Such tumors respond to additional treatment with fulvestrant or even tamoxifen. On the other hand, in tumors overexpressing HER2, acquired resistance to estrogen deprivation therapy involves the loss of ER and ER-regulated genes and further up-regulation of growth factor signaling rendering the tumor hormonal therapy resistant. This process can be delayed or reversed by simultaneous treatment with growth factor pathway inhibitors. This strategy is now being tested in clinical trials.
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214
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Come SE, Buzdar AU, Ingle JN, Arteaga CL, Brodie AM, Colditz GA, Johnston SR, Kristensen VN, Lønning PE, McDonnell DP, Osborne CK, Russo J, Santen RJ, Yee D, Hart CS. Proceedings of the Fourth International Conference on Recent Advances and Future Directions in Endocrine Manipulation of Breast Cancer: Conference Summary Statement. Clin Cancer Res 2005. [DOI: 10.1158/1078-0432.861s.11.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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215
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Come SE, Buzdar AU, Ingle JN, Arteaga CL, Brodie AM, Colditz GA, Johnston SRD, Kristensen VN, Lønning PE, McDonnell DP, Osborne CK, Russo J, Santen RJ, Yee D, Hart CS. Proceedings of the Fourth International Conference on Recent Advances and Future Directions in Endocrine Manipulation of Breast Cancer: conference summary statement. Clin Cancer Res 2005; 11:861s-4s. [PMID: 15701878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
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216
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Osborne CK, Shou J, Massarweh S, Schiff R. Crosstalk between Estrogen Receptor and Growth Factor Receptor Pathways as a Cause for Endocrine Therapy Resistance in Breast Cancer. Clin Cancer Res 2005. [DOI: 10.1158/1078-0432.865s.11.2] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Abstract
Data suggest that breast cancer growth is regulated by coordinated actions of the estrogen receptor (ER) and various growth factor receptor signaling pathways. In tumors with active growth factor receptor signaling (e.g., HER2 amplification), tamoxifen may lose its estrogen antagonist activity and may acquire more agonist-like activity, resulting in tumor growth stimulation. Because treatments designed to deprive the ER of its ligand estrogen will reduce signaling from both nuclear and membrane ER, aromatase inhibitors might be expected to be superior to tamoxifen in tumors with high growth factor receptor content, such as those overexpressing HER2. Recent clinical studies suggest that this is the case in humans, as trials of aromatase inhibitors show superior results compared with tamoxifen, especially in tumors overexpressing HER2. Although estrogen deprivation therapy is often effective in ER-positive breast cancer, de novo and acquired resistance are still problematic. Experimental models suggest that in one form of resistance to estrogen deprivation therapy, the tumor becomes supersensitive to low residual estrogen concentrations perhaps because of activation of mitogen-activated protein kinase. Such tumors respond to additional treatment with fulvestrant or even tamoxifen. On the other hand, in tumors overexpressing HER2, acquired resistance to estrogen deprivation therapy involves the loss of ER and ER-regulated genes and further up-regulation of growth factor signaling rendering the tumor hormonal therapy resistant. This process can be delayed or reversed by simultaneous treatment with growth factor pathway inhibitors. This strategy is now being tested in clinical trials.
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217
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Howell A, Pippen J, Elledge RM, Mauriac L, Vergote I, Jones SE, Come SE, Osborne CK, Robertson JFR. Fulvestrant versus anastrozole for the treatment of advanced breast carcinoma. Cancer 2005; 104:236-9. [PMID: 15937908 DOI: 10.1002/cncr.21163] [Citation(s) in RCA: 127] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND Fulvestrant is an estrogen receptor antagonist with no agonist effects. In the second-line treatment of advanced breast carcinoma, fulvestrant was shown previously to be as effective as the third-generation aromatase inhibitor, anastrozole, in terms of time to disease progression and objective response rates. The authors reported the overall survival results from these studies. METHODS A prospectively planned, combined, overall survival analysis was performed, including data from two Phase III trials that compared the efficacy and tolerability of fulvestrant (250 mg monthly; n = 428) with anastrozole (1 mg daily; n = 423) in the treatment of postmenopausal women with advanced breast carcinoma who had disease progression after receipt of previous endocrine treatment. RESULTS At an extended median follow-up of 27.0 months (range, 0-66.9 months), 319 (74.5%) patients in the fulvestrant group and 322 (76.1%) patients in the anastrozole group had died. Prolonged survival was observed with both drugs, with 10-20% of patients still alive > 5 years after randomization. The median overall survival was similar between treatments, being 27.4 months and 27.7 months in fulvestrant and anastrozole-treated patients, respectively (hazards ratio, 0.98; 95% confidence interval, 0.84-1.15; P = 0.809). Fulvestrant continued to be well tolerated, and was associated with a significantly lower incidence of joint disorders compared with anastrozole (P = 0.0234). CONCLUSIONS The current analysis showed that fulvestrant was similar to anastrozole with respect to overall survival in the second-line treatment of postmenopausal women with advanced breast carcinoma.
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218
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Pierce LJ, Hutchins LF, Green SR, Lew DL, Gralow JR, Livingston RB, Osborne CK, Albain KS. Sequencing of Tamoxifen and Radiotherapy After Breast-Conserving Surgery in Early-Stage Breast Cancer. J Clin Oncol 2005; 23:24-9. [PMID: 15545669 DOI: 10.1200/jco.2005.01.198] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Purpose Tamoxifen (TAM) is thought to exert a cytostatic effect on hormone-sensitive breast cancer cells. Some preclinical studies show reduced radiosensitivity in irradiated malignant mammary epithelial cells when pretreated with TAM; other studies refute these results. Recent randomized clinical trials suggest an antagonistic effect of TAM on cytotoxic therapy, with improved disease-free survival (DFS) with sequential versus concurrent TAM. An exploratory analysis was undertaken to evaluate the optimal sequencing of TAM and radiotherapy (RT) after breast-conserving surgery. Patients and Methods Southwest Oncology Group trial 8897 (Intergroup 0102) randomly assigned node-negative women with T1-3 breast cancers to cyclophosphamide, doxorubicin, fluorouracil (CAF); CAF → TAM; cyclophosphamide, methotrexate, fluorouracil (CMF); and CMF → TAM. For this analysis, data are reported only in the TAM groups. RT was allowed either before adjuvant therapy (sequential [SEQ] RT; 107 patients) or after chemotherapy but concurrent with TAM (concurrent [CONC] RT; 202 patients). Survival data were adjusted for receptor status, age, and tumor size. Results With a median follow-up of 10.3 years, 10-year DFS values were 83% and 83% for CONC versus SEQ RT groups (log-rank P = .73; P = .76 adjusted for patient characteristics), and 10-year overall survivals were 88% and 90%, respectively (log-rank P = .59; adjusted P = .65). Patterns of failure showed no increase in in-breast recurrence rates between CONC RT and SEQ RT groups, with 10-year local recurrence rates of 7% for CONC RT and 5% for SEQ RT (hazard ratio, 0.73; 95% CI, 0.26 to 2.04; P = .54). Conclusion The current analysis does not suggest an adverse effect on local or systemic control with CONC versus SEQ TAM and RT in node-negative breast cancer. A randomized trial is encouraged to validate these results.
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219
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Shou J, Massarweh S, Osborne CK, Wakeling AE, Ali S, Weiss H, Schiff R. Mechanisms of tamoxifen resistance: increased estrogen receptor-HER2/neu cross-talk in ER/HER2-positive breast cancer. J Natl Cancer Inst 2004; 96:926-35. [PMID: 15199112 DOI: 10.1093/jnci/djh166] [Citation(s) in RCA: 848] [Impact Index Per Article: 42.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Patients receiving adjuvant tamoxifen whose tumors express high levels of both HER2/neu (HER2) and the estrogen receptor (ER) coactivator AIB1 often develop tamoxifen resistance. We used a breast cancer model system with high expression of AIB1 and HER2 to investigate the possible mechanisms underlying this resistance. METHODS MCF-7 breast cancer cells, which express high levels of AIB1, and a tamoxifen-resistant derivative cell line engineered to overexpress HER2 (MCF-7/HER2-18) were treated with estrogen, tamoxifen, epidermal growth factor (EGF), or heregulin in the absence or presence of the EGF receptor (EGFR) tyrosine kinase inhibitor gefitinib. We analyzed phosphorylation of signaling intermediates by immunoblotting, ER transcriptional activity with reporter gene constructs and immunoblot analysis of endogenous gene products, promoter assembly by chromatin immunoprecipitation (ChIP) assay, and tumor cell growth in vitro by anchorage-independent colony formation and in vivo using xenografts in nude mice. RESULTS MCF-7/HER2-18 tumors were completely growth inhibited by estrogen deprivation but were growth stimulated by tamoxifen. Molecular cross-talk between the ER and HER2 pathways was increased in the MCF-7/HER-2 cells compared with MCF-7 cells, with cross-phosphorylation and activation of both the ER and the EGFR/HER2 receptors, the signaling molecules AKT and ERK 1,2 mitogen-activated protein kinase (MAPK), and AIB1 itself with both estrogen and tamoxifen treatment. Tamoxifen recruited coactivator complexes (ER, AIB1, CBP, p300) to the ER-regulated pS2 gene promoter in MCF-7/HER2-18 cells and corepressor complexes (NCoR, histone deacetylase 3) in MCF-7 cells. Gefitinib pretreatment blocked receptor cross-talk, reestablished corepressor complexes with tamoxifen-bound ER on target gene promoters, eliminated tamoxifen's agonist effects, and restored its antitumor activity both in vitro and in vivo in MCF-7/HER2-18 cells. CONCLUSIONS Tamoxifen behaves as an estrogen agonist in breast cancer cells that express high levels of AIB1 and HER2, resulting in de novo resistance. Gefitinib's ability to eliminate this cross-talk and to restore tamoxifen's antitumor effects should be tested in the clinic.
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MESH Headings
- Animals
- Antineoplastic Agents, Hormonal/pharmacology
- Breast Neoplasms/drug therapy
- Breast Neoplasms/metabolism
- Cell Line, Tumor
- Chemotherapy, Adjuvant
- Drug Resistance, Neoplasm
- Enzyme Inhibitors/pharmacology
- Epidermal Growth Factor/antagonists & inhibitors
- Estrogen Receptor Modulators/pharmacology
- Female
- Gefitinib
- Gene Expression Regulation, Neoplastic/drug effects
- Humans
- Mice
- Mice, Inbred BALB C
- Mice, Nude
- Phosphorylation/drug effects
- Protein-Tyrosine Kinases/antagonists & inhibitors
- Quinazolines/pharmacology
- Receptor Cross-Talk/drug effects
- Receptor, ErbB-2/drug effects
- Receptor, ErbB-2/metabolism
- Receptors, Estrogen/drug effects
- Receptors, Estrogen/metabolism
- Signal Transduction/drug effects
- Tamoxifen/pharmacology
- Transplantation, Heterologous
- Up-Regulation/drug effects
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220
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Howell A, Robertson JFR, Abram P, Lichinitser MR, Elledge R, Bajetta E, Watanabe T, Morris C, Webster A, Dimery I, Osborne CK. Comparison of fulvestrant versus tamoxifen for the treatment of advanced breast cancer in postmenopausal women previously untreated with endocrine therapy: a multinational, double-blind, randomized trial. J Clin Oncol 2004; 22:1605-13. [PMID: 15117982 DOI: 10.1200/jco.2004.02.112] [Citation(s) in RCA: 320] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE To evaluate the efficacy and tolerability of fulvestrant (Faslodex; AstraZeneca Pharmaceuticals LP, Wilmington, DE), a new estrogen receptor (ER) antagonist that downregulates ER and has no agonist effects, versus tamoxifen, an antiestrogen with agonist and antagonist effects, for the treatment of advanced breast cancer in postmenopausal women. PATIENTS AND METHODS In this multicenter, double-blind, randomized trial, patients with metastatic/locally advanced breast cancer previously untreated for advanced disease were randomly assigned to receive either fulvestrant (250 mg, via intramuscular injection, once monthly; n = 313) or tamoxifen (20 mg, orally, once daily; n = 274). Patients' tumors were positive for ER (ER+) and/or progesterone receptor (PgR+), or had an unknown receptor status. RESULTS At a median follow-up of 14.5 months, there was no significant difference between fulvestrant and tamoxifen for the primary end point of time to progression (TTP; median TTP, 6.8 months and 8.3 months, respectively; hazard ratio, 1.18; 95% CI, 0.98 to 1.44; P =.088). In a prospectively planned subset analysis of patients with known ER+ and/or PgR+ tumors ( approximately 78%), median TTP was 8.2 months for fulvestrant and 8.3 months for tamoxifen (hazard ratio, 1.10; 95% CI, 0.89 to 1.36; P =.39). The objective response rate for the overall population was 31.6% with fulvestrant and 33.9% with tamoxifen, and 33.2% and 31.1%, respectively, in the known hormone receptor-positive subgroup. Both treatments were well tolerated. CONCLUSION In the overall population, between-group differences in efficacy end points favored tamoxifen, and statistical noninferiority of fulvestrant could not be demonstrated. However, in patients with hormone receptor-positive tumors, fulvestrant had similar efficacy to tamoxifen and was well tolerated.
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MESH Headings
- Administration, Oral
- Adult
- Aged
- Aged, 80 and over
- Antineoplastic Agents, Hormonal/administration & dosage
- Antineoplastic Agents, Hormonal/adverse effects
- Antineoplastic Agents, Hormonal/therapeutic use
- Breast Neoplasms/drug therapy
- Breast Neoplasms/pathology
- Disease Progression
- Disease-Free Survival
- Double-Blind Method
- Estradiol/administration & dosage
- Estradiol/adverse effects
- Estradiol/analogs & derivatives
- Estradiol/therapeutic use
- Female
- Fulvestrant
- Humans
- Injections, Intramuscular
- Middle Aged
- Receptors, Estrogen/analysis
- Receptors, Estrogen/biosynthesis
- Receptors, Progesterone/analysis
- Receptors, Progesterone/biosynthesis
- Tamoxifen/administration & dosage
- Tamoxifen/adverse effects
- Tamoxifen/therapeutic use
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221
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Osborne CK, Schiff R. Growth factor receptor cross-talk with estrogen receptor as a mechanism for tamoxifen resistance in breast cancer. Breast 2004; 12:362-7. [PMID: 14659106 DOI: 10.1016/s0960-9776(03)00137-1] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Breast cancer growth is regulated by steroid hormones and by polypeptide hormones and growth factors. Endocrine therapies for breast cancer have been designed to interrupt estrogen signaling by either blocking its receptor (ER) or by lowering the amount of estrogen available in the cell for binding. These therapies are very effective in many patients but de novo and acquired resistance are common. Growing evidence suggests that cross-talk between ER and growth factor receptor pathways contributes to the development of this resistance. Signaling via the EGF receptor and HER-2/neu can activate both ER and the important ER coactivator AIB1. In turn, ER located in the cell membrane can activate the growth factor receptor pathways. Breast tumors with high levels of AIB1 and HER-2 may be resistant to tamoxifen because of an increase in its estrogen agonist activity.
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222
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Osborne CK, Wakeling A, Nicholson RI. Fulvestrant: an oestrogen receptor antagonist with a novel mechanism of action. Br J Cancer 2004; 90 Suppl 1:S2-6. [PMID: 15094757 PMCID: PMC2750773 DOI: 10.1038/sj.bjc.6601629] [Citation(s) in RCA: 279] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Due to their favourable tolerability profiles, endocrine therapies have long been considered the treatment of choice for hormone-sensitive metastatic breast cancer. However, the oestrogen agonist effects of the available selective oestrogen receptor modulators, such as tamoxifen, and the development of cross-resistance between endocrine therapies with similar modes of action have led to the need for new treatments that act through different mechanisms. Fulvestrant (‘Faslodex’) is the first of a new type of endocrine treatment – an oestrogen receptor (ER) antagonist that downregulates the ER and has no agonist effects. This article provides an overview of the current understanding of ER signalling and illustrates the unique mode of action of fulvestrant. Preclinical and clinical study data are presented in support of the novel mechanism of action of this new type of ER antagonist.
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223
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Schiff R, Massarweh SA, Shou J, Bharwani L, Mohsin SK, Osborne CK. Cross-talk between estrogen receptor and growth factor pathways as a molecular target for overcoming endocrine resistance. Clin Cancer Res 2004; 10:331S-6S. [PMID: 14734488 DOI: 10.1158/1078-0432.ccr-031212] [Citation(s) in RCA: 338] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Introduced more than 100 years ago, endocrine therapy is still the most important systemic therapy for all stages of estrogen receptor (ER) -positive breast tumors. A major clinical problem limiting the usefulness of this therapy is tumor resistance, either de novo or acquired during the course of the treatment. Relatively new discoveries emphasize the complexity of ER signaling and its multiple regulatory interactions with growth factor and other kinase signaling pathways. Both genomic (nuclear) and nongenomic (membrane and cytoplasmic) ER activities contribute to this intimate cross-talk, which is probably a fundamental factor in endocrine resistance. New targeted therapies, especially against the epidermal growth factor receptor/HER-2 pathway, should be carefully evaluated in more (bio)logical strategies to enable them to be exploited appropriately. A strategy of combining endocrine therapy (particularly tamoxifen) with these inhibitors, to circumvent de novo and acquired resistance, will be discussed. We will also emphasize open questions and future challenges in the dynamic research field of molecular ER biology from the endocrine therapy perspective.
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224
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Howell A, Osborne CK, Mauriac L. Spreading the word, but not too thinly. Lancet 2004; 363:165-6. [PMID: 14726176 DOI: 10.1016/s0140-6736(03)15273-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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225
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Lu C, Speers C, Zhang Y, Xu X, Hill J, Steinbis E, Celestino J, Shen Q, Kim H, Hilsenbeck S, Mohsin SK, Wakeling A, Osborne CK, Brown PH. Effect of epidermal growth factor receptor inhibitor on development of estrogen receptor-negative mammary tumors. J Natl Cancer Inst 2004; 95:1825-33. [PMID: 14679152 DOI: 10.1093/jnci/djg117] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Although antiestrogens have been effective in preventing estrogen receptor (ER)-positive breast cancer, chemopreventive agents are still needed to prevent ER-negative breast cancer. Tyrosine kinase inhibitors are promising agents for the treatment and prevention of human cancers. ZD1839 (gefitinib or Iressa) is an orally active epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor that blocks signal transduction pathways in epithelial cells. We examined whether ZD1839 blocks signal transduction and prevents the development of ER-negative breast cancer. METHODS The ability of ZD1839 to block signal transduction in normal, immortalized, and malignant breast cells was assessed by western blotting with specific antibodies to detect phosphorylation of cytoplasmic signaling molecules. The effect of ZD1839 on growth of these breast cells was assessed with anchorage-dependent and anchorage-independent growth assays. Its effect on ER-negative mammary tumorigenesis was assessed in MMTV-erbB2 transgenic mice. All statistical tests were two-sided. RESULTS ZD1839 suppressed the phosphorylation of EGFR and mitogen-activated protein kinase in normal and malignant breast cells. ZD1839 treatment statistically significantly suppressed mammary tumorigenesis in MMTV-erbB2 transgenic mice; median time to tumor development was approximately 230 days in vehicle-treated mice and more than 310 days in mice treated with ZD1839 at 100 mg/kg (P<.001). ZD1839 reduced proliferation of normal breast cells by 20.3% (95% confidence interval [CI] = -13.7% to 44.2%) and of tumor cells by 42.0% (95% CI = 20.2% to 58.2%). ZD1839 also increased expression of the cell cycle regulator p27 in normal mammary tissue by 48.7% (95% CI = 27.0% to 74.2%) and in tumor tissue by 50.3% (95% CI = 35.8% to 66.7%). CONCLUSION This study appears to provide the preclinical rationale for the development of these EGFR tyrosine kinase inhibitors for the prevention of human breast cancer.
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