Conflicting evidence on the frequency of ESR1 amplification in breast cancer
ABSTRACT An earlier report of high-frequency ESR1 amplification in breast cancer is now challenged by correspondence from four groups. This discussion of whether or not there is something 'FISHy' about ESR1 amplification highlights the difficulty of validating such observations, leaving the frequency and clinical significance of ESR1 amplification in breast cancer an open question.
SourceAvailable from: Cathy B Moelans[Show abstract] [Hide abstract]
ABSTRACT: Gene amplification is an important mechanism for oncogene activation, a crucial step in carcinogenesis. Compared to female breast cancer, little is known on the genetic makeup of male breast cancer, because large series are lacking. Copy number changes of 21 breast cancer related genes were studied in 110 male breast cancers using multiplex ligation-dependent probe amplification. A ratio of >1.3 was regarded indicative for gene copy number gain and a ratio >2.0 for gene amplification. Data were correlated with clinicopathological features, prognosis and 17 genes were compared with a group of female breast cancers. Gene copy number gain of CCND1, TRAF4, CDC6 and MTDH was seen in >40 % of the male breast cancer cases, with also frequent amplification. The number of genes with copy number gain and several single genes were associated with high grade, but only CCND1 amplification was an independent predictor of adverse survival in Cox regression (p = 0.015; hazard ratio 3.0). In unsupervised hierarchical clustering a distinctive group of male breast cancer with poor prognosis (p = 0.009; hazard ratio 3.4) was identified, characterized by frequent CCND1, MTDH, CDC6, ADAM9, TRAF4 and MYC copy number gain. Compared to female breast cancers, EGFR (p = 0.005) and CCND1 (p = 0.041) copy number gain was more often seen in male breast cancer, while copy number gain of EMSY (p = 0.004) and CPD (p = 0.001) and amplification in general was less frequent. In conclusion, several female breast cancer genes also seem to be important in male breast carcinogenesis. However, there are also clear differences in copy number changes between male and female breast cancers, pointing toward differences in carcinogenesis between male and female breast cancer and emphasizing the importance of identifying biomarkers and therapeutic agents based on research in male breast cancer. In addition CCND1 amplification seems to be an independent prognosticator in male breast cancer.Breast Cancer Research and Treatment 04/2012; 135(1):49-58. DOI:10.1007/s10549-012-2051-3 · 4.47 Impact Factor
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ABSTRACT: The Estrogen Receptor (ER) is an established predictive marker for the selection of adjuvant endocrine treatment in early breast cancer. During the 1990s Immunohistochemistry (IHC) replaced cytosol based assays for determination of ER status. This study examined the association between ER protein level determined by two different methods and ESR1 gene copy number. From 289 primary high-risk breast cancer patients, randomized in the Danish Breast Cancer Cooperative Group (DBCG) 77C trial, results from cytosolic ER levels were available from ligand binding assays. Archival tumor tissue was retrieved from 257 patients. ESR1/CEN-6 ratio was analyzed successfully by Fluorescence In Situ Hybridization (FISH) in 220 (86%) patients. ESR1 amplification (ESR1/CEN-6 ≥ 2.00) was observed in 23% of the patients and ESR1 deletion (ESR1/CEN-6 < 0.80) was observed in 32%. Further, we identified ESR1 gain (ratio ESR1/CEN-6 from 1.30 to 1.99) in 19% of the patients. A positive correlation of ESR1 FISH with both ER-cytosol and ER IHC was found (p < 0.0001). Amplification and gain of the ESR1 gene are associated with higher ER protein content measured by ligand binding assay and a more intense nuclear staining by IHC compared to tumors with normal ESR1 gene status. Major variations in ER measured by ligand binding assay and IHC are observed within all ESR1 copy number subgroups and other mechanisms than gene copy number seem to contribute to the ER protein content in the tumors.Molecular oncology 05/2012; 6(4):428-36. DOI:10.1016/j.molonc.2012.04.003 · 6.70 Impact Factor
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ABSTRACT: Breast cancer occurs at a high frequency in women and, given this fact, a primary focus of breast cancer research has been the study of estrogen receptor α (ER) signaling. However, androgens are known to play a role in normal breast physiology and therefore androgen receptor (AR) signaling is becoming increasingly recognized as an important contributor towards breast carcinogenesis. Moreover, the high frequency of AR expression in breast cancer makes it an attractive therapeutic target, but the ability to exploit AR for therapy has been difficult. Here we review the historical use of androgen/anti-androgen therapies in breast cancer, the challenges of accurately modeling nuclear hormone receptor signaling in vitro, and the presence and prognostic significance of AR in breast cancer.American Journal of Cancer Research 01/2012; 2(4):434-45. · 3.97 Impact Factor