REFERENCES
1. Harvey JM, Clark GM, Osborne CK, Allred DC. Estrogen receptor status by immunohistochemistry is superior to the ligand-binding assay for predicting response to adjuvant endocrine therapy in breast cancer. J Clin Oncol 1999;17:1474-81.
2. Joel PB, Traish AM, Lannigan DA. Estradiol and phorbol ester cause phosphorylation of serine 118 in the human estrogen receptor. Mol Endocrinol 1995;9:1041-52.
3. Le Goff P, Montano MM, Schodin DJ, Katzenellenbogen BS. Phosphorylation of the human estrogen receptor. Identification of hormone-regulated sites and examination of their influence on transcriptional activity. J Biol Chem 1994;269:4458-66.
4. Kato S, Endoh H, Masuhiro Y, Kitamoto T, Uchiyama S, et al. Activation of the estrogen receptor through phosphorylation by mitogen-activated protein kinase. Science 1995;270:1491-4.
5. Zhou W SJ. Links between oestrogen receptor activation and proteolysis: relevance to hormone-regulated cancer therapy. Nat Rev Cancer 2014;14:26-38.
6. Zwart W, de Leeuw R, Rondaij M, Neefjes J, Mancini MA, et al. The hinge region of the human estrogen receptor determines functional synergy between AF-1 and AF-2 in the quantitative response to estradiol and tamoxifen. J Cell Sci 2010;123:1253-61.
7. Davies C, Godwin J, Gray R, Clarke M, et al; Early Breast Cancer Trialists’ Collaborative G (EBCTCG). Relevance of breast cancer hormone receptors and other factors to the efficacy of adjuvant tamoxifen: patient-level meta-analysis of randomised trials. Lancet 2011;378:771-84.
8. Ma CX, Reinert T, Chmielewska I, Ellis MJ. Mechanisms of aromatase inhibitor resistance. Nat Rev Cancer 2015;15:261-75.
9. Osborne CK, Bardou V, Hopp TA, Chamness GC, Hilsenbeck SG, et al. Role of the estrogen receptor coactivator AIB1 (SRC-3) and HER-2/neu in tamoxifen resistance in breast cancer. J Natl Cancer Inst 2003;95:353-61.
10. Arpino G, Green SJ, Allred DC, Lew D, Martino S, et al. HER-2 amplification, HER-1 expression, and tamoxifen response in estrogen receptor-positive metastatic breast cancer: a southwest oncology group study. Clin Cancer Res 2004;10:5670-6.
11. Fan P, Wang J, Santen RJ, Yue W. Long-term treatment with tamoxifen facilitates translocation of estrogen receptor alpha out of the nucleus and enhances its interaction with EGFR in MCF-7 breast cancer cells. Cancer Res 2007;67:1352-60.
12. Song RX, Barnes CJ, Zhang Z, Bao Y, Kumar R, et al. The role of Shc and insulin-like growth factor 1 receptor in mediating the translocation of estrogen receptor alpha to the plasma membrane. Proc Natl Acad Sci U S A 2004;101:2076-81.
13. Osborne CK, Neven P, Dirix LY, Mackey JR, Robert J, et al. Gefitinib or placebo in combination with tamoxifen in patients with hormone receptor-positive metastatic breast cancer: a randomized phase II study. Clin Cancer Res 2011;17:1147-59.
14. Ellis MJ, Perou CM. The genomic landscape of breast cancer as a therapeutic roadmap. Cancer Discov 2013;3:27-34.
15. Sanchez CG, Ma CX, Crowder RJ, Guintoli T, Phommaly C, et al. Preclinical modeling of combined phosphatidylinositol-3-kinase inhibition with endocrine therapy for estrogen receptor-positive breast cancer. Breast Cancer Res 2011;13:R21.
16. Baselga J, Campone M, Piccart M, Burris HA 3rd, Rugo HS, et al. Everolimus in postmenopausal hormone-receptor-positive advanced breast cancer. N Engl J Med 2012;366:520-9.
17. Di Leo A, Johnston S, Lee KS, Ciruelos E, Lonning PE, et al. Buparlisib plus fulvestrant in postmenopausal women with hormone-receptor-positive, HER2-negative, advanced breast cancer progressing on or after mTOR inhibition (BELLE-3): a randomised, double-blind, placebo-controlled, phase 3 trial. Lancet Oncol 2018;19:87-100.
18. André F, Ciruelos EM, Rubovszky G, Campone M, Loibl S, et al. Alpelisib (ALP) + fulvestrant (FUL) for advanced breast cancer (ABC): results of the phase 3 SOLAR-1 trial. Munich, Germany: ESMO Congress; 2018.
19. Cancer Genome Atlas N. Comprehensive molecular portraits of human breast tumours. Nature 2012;490:61-70.
20. Thangavel C, Dean JL, Ertel A, Knudsen KE, Aldaz CM, et al. Therapeutically activating RB: reestablishing cell cycle control in endocrine therapy-resistant breast cancer. Endocr Relat Cancer 2011;18:333-45.
21. Ma CX, Gao F, Luo J, Northfelt DW, Goetz M, et al. NeoPalAna: neoadjuvant palbociclib, a cyclin-dependent kinase 4/6 inhibitor, and anastrozole for clinical stage 2 or 3 estrogen receptor-positive breast cancer. Clin Cancer Res 2017;23:4055-65.
22. Basudan A, Priedigkeit N, Hartmaier RJ, Sokol ES, Bahreini A, et al. Frequent ESR1 and CDK pathway copy-number alterations in metastatic breast cancer. Mol Cancer Res 2019;17:457-68.
23. Zhang QX, Borg A, Wolf DM, Oesterreich S, Fuqua SA. An estrogen receptor mutant with strong hormone-independent activity from a metastatic breast cancer. Cancer Res 1997;57:1244-9.
24. Pejerrey SM, Dustin D, Kim JA, Gu G, Rechoum Y, et al. The impact of ESR1 mutations on the treatment of metastatic breast cancer. Horm Cancer 2018;9:215-28.
25. Niu J, Andres G, Kramer K, Kundranda MN, Alvarez RH, et al. Incidence and clinical significance of ESR1 mutations in heavily pretreated metastatic breast cancer patients. Onco Targets Ther 2015;8:3323-8.
26. Borg A, Tandon AK, Sigurdsson H, Clark GM, Ferno M, et al. HER-2/neu amplification predicts poor survival in node-positive breast cancer. Cancer Res 1990;50:4332-7.
27. Turner N, Pearson A, Sharpe R, Lambros M, Geyer F, et al. FGFR1 amplification drives endocrine therapy resistance and is a therapeutic target in breast cancer. Cancer Res 2010;70:2085-94.
28. Nembrot M, Quintana B, Mordoh J. Estrogen receptor gene amplification is found in some estrogen receptor-positive human breast tumors. Biochem Biophys Res Commun 1990;166:601-7.
29. Holst F, Stahl PR, Ruiz C, Hellwinkel O, Jehan Z, et al. Estrogen receptor alpha (ESR1) gene amplification is frequent in breast cancer. Nat Genet 2007;39:655-60.
30. Brown LA, Hoog J, Chin SF, Tao Y, Zayed AA, et al. ESR1 gene amplification in breast cancer: a common phenomenon? Nat Genet 2008;40:806-7.
31. Horlings HM, Bergamaschi A, Nordgard SH, Kim YH, Han W, et al. ESR1 gene amplification in breast cancer: a common phenomenon? Nat Genet 2008;40:807-8.
32. Reis-Filho JS, Drury S, Lambros MB, Marchio C, Johnson N, et al. ESR1 gene amplification in breast cancer: a common phenomenon? Nat Genet 2008;40:809-10.
33. Vincent-Salomon A, Raynal V, Lucchesi C, Gruel N, Delattre O. ESR1 gene amplification in breast cancer: a common phenomenon? Nat Genet 2008;40:809.
34. Tsiambas E, Georgiannos SN, Salemis N, Alexopoulou D, Lambropoulou S, et al. Significance of estrogen receptor 1 (ESR-1) gene imbalances in colon and hepatocellular carcinomas based on tissue microarrays analysis. Med Oncol 2011;28:934-40.
35. Tomita S, Zhang Z, Nakano M, Ibusuki M, Kawazoe T, et al. Estrogen receptor alpha gene ESR1 amplification may predict endocrine therapy responsiveness in breast cancer patients. Cancer Sci 2009;100:1012-7.
36. Moelans CB, de Weger RA, Monsuur HN, Vijzelaar R, van Diest PJ. Molecular profiling of invasive breast cancer by multiplex ligation-dependent probe amplification-based copy number analysis of tumor suppressor and oncogenes. Mod Pathol 2010;23:1029-39.
37. Jeselsohn R, Yelensky R, Buchwalter G, Frampton G, Meric-Bernstam F, et al. Emergence of constitutively active estrogen receptor-alpha mutations in pretreated advanced estrogen receptor-positive breast cancer. Clin Cancer Res 2014;20:1757-67.
38. Schiff R, Veeraraghavan J, Fu X. Abstract SY01-01: Endocrine resistance in metastatic breast cancer: Mechanisms and new therapeutic strategies. Chicago, IL: AACR Annual Meeting; 2018.
39. Basudan A, Priedigkeit N, Hartmaier RJ, Sokol ES, Bahreini A, et al. Frequent ESR1 and CDK pathway copy-number alterations in metastatic breast cancer. Mol Cancer Res 2019;17:457-68.
40. Markiewicz A, Welnicka-Jaskiewicz M, Skokowski J, Jaskiewicz J, Szade J, et al. Prognostic significance of ESR1 amplification and ESR1 PvuII, CYP2C19*2, UGT2B15*2 polymorphisms in breast cancer patients. PLoS One 2013;8:e72219.
41. Nielsen KV, Bent Ejlertsen, Sven Müller, Susanne Møller, Birgitte B, et al. Amplification of ESR1 may predict resistance to adjuvant tamoxifen in postmenopausal patients with hormone receptor positive breast cancer. Breast Cancer Res Treat 2011;127:345-55.
42. Holst F, Singer CF. ESR1-amplification-associated estrogen receptor alpha activity in breast cancer. Trends Endocrinol Metab 2016;27:751-2.
43. Khan SA, Rogers MA, Khurana KK, Meguid MM, Numann PJ. Estrogen receptor expression in benign breast epithelium and breast cancer risk. J Natl Cancer Inst 1998;90:37-42.
44. Shoker BS, Jarvis C, Sibson DR, Walker C, Sloane JP. Oestrogen receptor expression in the normal and pre-cancerous breast. J Pathol 1999;188:237-44.
45. Burkhardt L, Grob TJ, Hermann I, Burandt E, Choschzick M, et al. Gene amplification in ductal carcinoma in situ of the breast. Breast Cancer Res Treat 2010;123:757-65.
46. Quenel-Tueux N, Debled M, Rudewicz J, MacGrogan G, Pulido M, et al. Clinical and genomic analysis of a randomised phase II study evaluating anastrozole and fulvestrant in postmenopausal patients treated for large operable or locally advanced hormone-receptor-positive breast cancer. Br J Cancer 2015;113:585-94.
47. Li S, Shen D, Shao J, Crowder R, Liu W, et al. Endocrine-therapy-resistant ESR1 variants revealed by genomic characterization of breast-cancer-derived xenografts. Cell Rep 2013;4:1116-30.
48. Aguilar H, Sole X, Bonifaci N, Serra-Musach J, Islam A, et al. Biological reprogramming in acquired resistance to endocrine therapy of breast cancer. Oncogene 2010;29:6071-83.
49. Haddow A, Watkinson JM, Paterson E, Koller PC. Influence of synthetic oestrogens on advanced malignant disease. Br Med J 1944;2:393-8.
50. Kota K, Adam Brufsky, Steffi Oesterreich, Adrian Lee. Estradiol as a targeted, late-line therapy in metastatic breast cancer with estrogen receptor amplification. Cureus 2017;9:e1434.
51. Magnani L, Frige G, Gadaleta RM, Corleone G, Fabris S, et al. Acquired CYP19A1 amplification is an early specific mechanism of aromatase inhibitor resistance in ERalpha metastatic breast cancer. Nat Genet 2017;49:444-50.
52. Weis KE, Ekena K, Thomas JA, Lazennec G, Katzenellenbogen BS. Constitutively active human estrogen receptors containing amino acid substitutions for tyrosine 537 in the receptor protein. Mol Endocrinol 1996;10:1388-98.
53. Toy W, Shen Y, Won H, Green B, Sakr RA, et al. ESR1 ligand-binding domain mutations in hormone-resistant breast cancer. Nat Genet 2013;45:1439-45.
54. Merenbakh-Lamin K, Ben-Baruch N, Yeheskel A, Dvir A, Soussan-Gutman L, et al. D538G mutation in estrogen receptor-alpha: a novel mechanism for acquired endocrine resistance in breast cancer. Cancer Res 2013;73:6856-64.
55. Robinson DR, Wu YM, Vats P, Su F, Lonigro RJ, et al. Activating ESR1 mutations in hormone-resistant metastatic breast cancer. Nat Genet 2013;45:1446-51.
56. Chandarlapaty S, Chen D, He W, Sung P, Samoila A, et al. Prevalence of ESR1 mutations in cell-free DNA and outcomes in metastatic breast cancer: a secondary analysis of the BOLERO-2 clinical trial. JAMA Oncol 2016;2:1310-5.
57. Spoerke JM, Gendreau S, Walter K, Qiu J, Wilson TR, et al. Heterogeneity and clinical significance of ESR1 mutations in ER-positive metastatic breast cancer patients receiving fulvestrant. Nat Commun 2016;7:11579.
58. Schiavon G, Hrebien S, Garcia-Murillas I, Cutts RJ, Pearson A, et al. Analysis of ESR1 mutation in circulating tumor DNA demonstrates evolution during therapy for metastatic breast cancer. Sci Transl Med 2015;7:313ra182.
59. Fribbens C, O’Leary B, Kilburn L, Hrebien S, Garcia-Murillas I, et al. Plasma ESR1 mutations and the treatment of estrogen receptor-positive advanced breast cancer. J Clin Oncol 2016;34:2961-8.
60. Wang P, Bahreini A, Gyanchandani R, Lucas PC, Hartmaier RJ, et al. Sensitive detection of mono-and polyclonal ESR1 mutations in primary tumors, metastatic lesions, and cell-free DNA of breast cancer patients. Clin Cancer Res 2016;22:1130-7.
61. Gelsomino L, Gu G, Rechoum Y, Beyer AR, Pejerrey SM, et al. Erratum to: ESR1 mutations affect anti-proliferative responses to tamoxifen through enhanced cross-talk with IGF signaling. Breast Cancer Res Treat 2017;163:639-40.
62. Harrod A, Fulton J, Nguyen VTM, Periyasamy M, Ramos-Garcia L, et al. Genomic modelling of the ESR1 Y537S mutation for evaluating function and new therapeutic approaches for metastatic breast cancer. Oncogene 2017;36:2286-96.
63. Toy W, Weir H, Razavi P, Lawson M, Goeppert AU, et al. Activating ESR1 mutations differentially affect the efficacy of ER antagonists. Cancer Discov 2017;7:277-87.
64. Jeselsohn R, Bergholz JS, Pun M, Cornwell M, Liu W, et al. Allele-specific chromatin recruitment and therapeutic vulnerabilities of ESR1 activating mutations. Cancer Cell 2018;33:173-86.e5.
65. Shang Y, Hu X, DiRenzo J, Lazar MA, Brown M. Cofactor dynamics and sufficiency in estrogen receptor-regulated transcription. Cell 2000;103:843-52.
66. Gates LA, Gu G, Chen Y, Rohira AD, Lei JT, et al. Proteomic profiling identifies key coactivators utilized by mutant ERalpha proteins as potential new therapeutic targets. Oncogene 2018;37:4581-98.
67. Osborne CK, Schiff R. Mechanisms of endocrine resistance in breast cancer. Annu Rev Med 2011;62:233-47.
68. Nagasawa J, Govek S, Kahraman M, Lai A, Bonnefous C, et al. Identification of an orally bioavailable chromene-based selective estrogen receptor degrader (SERD) that demonstrates robust activity in a model of tamoxifen-resistant breast cancer. J Med Chem 2018;61:7917-28.
69. Hamilton EP, Patel MR, Armstrong AC, Baird RD, Jhaveri K, et al. A first-in-human study of the new oral selective estrogen receptor degrader AZD9496 for ER(+)/HER2(-) advanced breast cancer. Clin Cancer Res 2018;24:3510-8.
70. Wardell SE, Ellis MJ, Alley HM, Eisele K, VanArsdale T, et al. Efficacy of SERD/SERM Hybrid-CDK4/6 inhibitor combinations in models of endocrine therapy-resistant breast cancer. Clin Cancer Res 2015;21:5121-30.
71. Turner NC, Ro J, Verma S, Huang Bartlett C, Cristofanilli M, et al. Palbociclib in hormone-receptor-positive advanced breast cancer. N Engl J Med 2015;373:209-19.
72. Giltnane JM, Hutchinson KE, Stricker TP, Formisano L, Young CD, et al. Genomic profiling of ER(+) breast cancers after short-term estrogen suppression reveals alterations associated with endocrine resistance. Sci Transl Med 2017;9.
73. Veeraraghavan J, Tan Y, Cao XX, Kim JA, Wang X, et al. Recurrent ESR1-CCDC170 rearrangements in an aggressive subset of oestrogen receptor-positive breast cancers. Nat Commun 2014;5:4577.
74. Dowsett M, Smith IE, Ebbs SR, Dixon JM, Skene A, et al. Prognostic value of Ki67 expression after short-term presurgical endocrine therapy for primary breast cancer. J Natl Cancer Inst 2007;99:167-70.
75. Lei JT, Shao J, Zhang J, Iglesia M, Chan DW, et al. Functional annotation of ESR1 gene fusions in estrogen receptor-positive breast cancer. Cell Rep 2018;24:1434-44e7.
76. Adelson K, Ramaswamy B, Sparano JA, Christos PJ, Wright JJ, et al. Randomized phase II trial of fulvestrant alone or in combination with bortezomib in hormone receptor-positive metastatic breast cancer resistant to aromatase inhibitors: a New York cancer consortium trial. NPJ Breast Cancer 2016;2:16037.
77. Hartmaier RJ, Trabucco SE, Priedigkeit N, Chung JH, Parachoniak CA, et al. Recurrent hyperactive ESR1 fusion proteins in endocrine therapy-resistant breast cancer. Ann Oncol 2018;29:872-80.
78. Tomlins SA, Rhodes DR, Perner S, Dhanasekaran SM, Mehra R, et al. Recurrent fusion of TMPRSS2 and ETS transcription factor genes in prostate cancer. Science 2005;310:644-8.
79. Mani RS, Tomlins SA, Callahan K, Ghosh A, Nyati MK, et al. Induced chromosomal proximity and gene fusions in prostate cancer. Science 2009;326:1230.
80. Haffner MC, Aryee MJ, Toubaji A, Esopi DM, Albadine R, et al. Androgen-induced TOP2B-mediated double-strand breaks and prostate cancer gene rearrangements. Nat Genet 2010;42:668-75.
81. Ju BG, Lunyak VV, Perissi V, Garcia-Bassets I, Rose DW, et al. A topoisomerase IIbeta-mediated dsDNA break required for regulated transcription. Science 2006;312:1798-802.
