00019606-200903000-00003ArticleDiagnostic Molecular PathologyDiagnostic Molecular Pathology© 2009 Lippincott Williams & Wilkins, Inc.18March 2009
p 22-29Quantitation of HER2 Expression or HER2:HER2 Dimers and Differential Survival in a Cohort of Metastatic Breast Cancer Patients Carefully Selected for
Trastuzumab Treatment Primarily by FISHOriginal ArticlesDesmedt, Christine PhD*; Sperinde, Jeff PhD†; Piette, Fanny PhD‡; Huang, Weidong MD, PhD†; Jin, Xueguang PhD†; Tan, Yuping PhD†; Durbecq, Virginie MD, PhD*; Larsimont, Denis MD, PhD*; Giuliani, Rosa MD, PhD*; Chappey, Colombe PhD†; Buyse, Marc PhD‡; Winslow, John PhD†; Piccart, Martine MD, PhD*; Sotiriou, Christos MD, PhD*; Petropoulos, Christos PhD†; Bates, Michael MD†*Department of Medical Oncology, Jules Bordet Institute, Brussels‡IDDI, Louvain-la-Neuve, Belgium†Monogram Biosciences Inc, South San Francisco, CASupported by Monogram Biosciences.Disclaimers: Jeff Sperinde, Weidong Huang, Xueguang Jin, Yuping Tan, Colombe Chappey, John Winslow, Christos Petropoulos, and Michael Bates are employees of and stockholders in Monogram Biosciences.Reprints: Michael Bates, MD, Vice President, Clinical Research, Monogram Biosciences Inc, 345 Oyster Point Blvd., South San Francisco, CA 94080 (e-mail:
[email protected]).AbstractThe selection of patients with HER2-positive breast cancer for treatment with trastuzumab is based on the measurement of HER2 protein expression by immunohistochemistry, or the presence of HER2 gene amplification by fluorescence in situ hybridization (FISH). By using multivariate analyses, we investigate the relationship between quantitative measurements of HER2 expression or HER2:HER2 dimers and objective response (Response Evaluation Criteria in Solid Tumors), time to progression, and breast cancer survival after
trastuzumab treatment in a cohort of patients with metastatic breast cancer who were primarily selected for treatment by FISH. The VeraTag assay, a proximity-based assay designed to quantitate protein expression and dimerization in formalin-fixed, paraffin-embedded tissue specimens, was used to measure HER2 protein expression and HER2:HER2 dimer levels. In a Cox proportional hazards analysis, higher HER2 expression or HER2:HER2 dimer levels were both correlated with longer survival (P=0.0058 and P=0.016, respectively) after treatment with trastuzumab in a population of patients that were either FISH-positive (90%) or immunohistochemistry 3+ (10%). Patients with higher levels of HER2 expression or HER2:HER2 dimers seemed to derive little benefit from the addition of concomitant chemotherapy to trastuzumab, whereas those with lower levels benefited significantly [interaction test P=0.43 (HER2 expression), P=0.27 (HER2:HER2 dimers)]. These data suggest that more quantitative or functional measurements of HER2 status may facilitate the development of more personalized treatment strategies for patients with metastatic breast cancer.The HER-family of receptor tyrosine kinases (EGFR/HER1, ErbB2/HER2, ErbB3/HER3, and ErbB4/HER4) plays a major role in the pathogenesis of many solid tumors. In approximately 25% of breast cancers, overexpression of HER2 has been linked to both adverse prognosis and improved responsiveness to treatment with trastuzumab (Herceptin, Genentech), a monoclonal antibody directed at the extracellular domain of HER2.1–5 Trastuzumab offers significant disease-free and overall survival advantages in both the metastatic and adjuvant settings in HER2 overexpressing patients.6–11 Current methodologies for the selection of HER2-positive patients include immunohistochemistry (IHC) to detect HER2 protein overexpression, and fluorescence in situ hybridization (FISH) to detect HER2 gene amplification.12–18 Despite these methods, only a fraction of HER2-positive patients with metastatic breast cancer (MBC) respond to trastuzumab, and a significant proportion of the responders relapse within 1 year. These clinical observations suggest the existence of both de novo and acquired resistance to trastuzumab.Here we describe the correlation between quantitative measurements of HER2 protein expression (H2T) or HER2:HER2 dimers (H2D) and breast cancer survival (BCS), time-to-progression (TTP), and Response Evaluation Criteria in Solid Tumors (RECIST) [RECIST criteria refer to standardized methods of assessing the response of solid tumors to treatment. Predefined target lesions are measured radiographically (computed tomography scan or magnetic resonance imaging recommended) before therapy and then again at follow-up intervals that are protocol-specific, but usually at 6 to 8 weeks. Responses are categorized as complete response (CR), partial response (PR), stable disease (SD), or progressive disease according to the specifications described by Therasse et al.19] responses after
trastuzumab treatment in a cohort of patients with MBC who were carefully preselected for amplification of HER2 by FISH (90%) or overexpression of HER2 by IHC (10%). Quantitative measurements are made by the VeraTag assay (Monogram Biosciences) using formalin-fixed, paraffin-embedded (FFPE) breast tumor specimens. HER2:HER2 dimers are defined in this assay as two HER2 receptors located within close proximity of one another. These could include HER2 molecules that interact along a defined protein-protein interface (true HER2:HER2 dimers), or HER2 monomers that are in close proximity (<∼100 nm) as a result of pathologic overexpression. Whether such HER2 homodimers serve as a marker of trastuzumab susceptibility as a result of their role in signal pathway activation or whether they simply represent clustered HER2 molecules that may serve as a better target for trastuzumab-mediated antibody-dependent cellular cytotoxicity is unclear at this time.MATERIALS AND METHODSThe VeraTag Technology and FISHThe VeraTag technology is a proximity-based method designed to accurately and reproducibly quantitate protein expression and protein-protein complexes, including cell surface dimers, in FFPE specimens. Detailed descriptions of the VeraTag assay and its performance characteristics are available elsewhere.20The VeraTag AssayAll materials, cell culture procedures, fixation, processing, paraffin-embedding, and microtomy for specimen preparation were provided and performed as described earlier. The H2T and H2D assays, including capillary electrophoresis, data analysis, and tumor content normalization were carried out as detailed earlier.20FISHThe detection of HER2/neu amplification was conducted by an independent clinical laboratory (PhenoPath Laboratories, Seattle, WA) by using the PathVysion assay (Abbott-Vysis Inc, Downers Grove, IL).Description of the Clinical CohortSeventy-one patients with MBC were treated in the trastuzumab Expanded Access Program or the Identified Patient Program (IPP) sponsored by F. Hoffman-LaRoche in Belgium before May 2002. The mean age of the patients was 51 years and the mean follow-up time was 20 months. The median TTP for the cohort was 8.1 months. The median BCS of the cohort was undefined, as 78.3% of the patients were still alive 18 months after treatment with trastuzumab. The patients were required to have MBC and most patients had prior experience with 2 or more chemotherapy regimens. Patients from the IPP were allowed to receive first line trastuzumab if it was given with paclitaxel. The patients received trastuzumab as a single agent or in combination with chemotherapy, primarily paclitaxel (Table 1). On-site monitoring visits were conducted to collect clinical data from the original source documents (medical records, case report forms, or imaging data). For the trastuzumab-only group, an independent response review (IRR) committee evaluated all data in a blinded fashion. The response was assessed radiographically, according to RECIST recommendations. As there was high concordance between the IRR and the oncologists who coordinated the study, the IRR was not required for the trastuzumab plus chemotherapy group. The patients who were enrolled but never treated and the patients who were receiving incomplete administrations of trastuzumab (1 to 5 wk) were excluded from the analysis, unless discontinuation was unequivocally ascribed to progressive disease. The patients with previous or concomitant cancer other than breast were excluded, as were patients without archival samples of their invasive breast cancer. Central confirmation of HER2 overexpression by FISH (N=64) or IHC (N=7) was mandatory. All study procedures were approved by the Ethics Committee of the Jules Bordet Institute.JOURNAL/dimp/04.03/00019606-200903000-00003/table1-3/v/2021-02-17T200000Z/r/image-tiff Clinical Characteristics of the Bordet CohortPreselection for HER2 Gene Amplification and Objective ResponseEighty percent of the cohort received treatment in the adjuvant setting and 58% received chemotherapy concomitantly with trastuzumab, whereas the remainder were treated with trastuzumab alone. It is worth noting that greater than 90% of the patients were selected for inclusion on the basis of FISH positivity (Table 1). There was mandatory confirmation of HER2 status and centralized collection of clinical data. As such, the stringency of selection for HER2 overexpression or gene amplification was high.Statistical MethodsMeasurements of H2T and H2D were tested for correlation with BCS, defined as the time from the start of Herceptin-containing treatment to cancer-associated death or the end of the follow-up period. Deaths not attributed to breast cancer were considered censored at the time of death. TTP was defined as the time from the start of Herceptin-containing treatment to progression (RECIST) or censor [end of follow-up (n=4) or change in treatment (n=23)]. Patients were classified as either high or low for each of the 2 variables, H2T and H2D, using the median of the distribution. High and low groups were compared for time-to-event end points using the Kaplan-Meier (KM) analysis. Cox proportional hazards models were fitted to determine the most significant correlates with outcome. Potential prognostic factors included HER2 expression, HER2:HER2 dimers, HER2 gene copy number as measured by centromere-corrected FISH (FISH/CEP17), treatment group (trastuzumab-only or trastuzumab plus chemotherapy), estrogen and progesterone receptor status, exposure to adjuvant hormonal therapy or adjuvant chemotherapy, time from metastasis to treatment, time from surgery to treatment, presence of metastases in the liver, lung, skin, bone, lymph nodes, brain, or other viscera, tumor size, number of involved lymph nodes, and total number of sites where metastases were found. Metastatic sites occurring in less than 10% of the total cohort were not considered as individual variables, but were included in the calculation of the total number of sites. A log transformation was applied to H2T and H2D to reduce the asymmetry of the distribution of these variables. A forward selection procedure was applied to enter successively the most statistically significant covariates until none of them was significant at the 0.05 level. The Cox models were used to classify patients in risk groups based on a multivariate score (equal to the linear combination of the prognostic factors retained as statistically significant in the model). Cox analyses were run separately for the entire cohort (N=71) and for the subset selected by FISH (N=64) to account for any variability introduced by the minority population selected by IHC. KM curves were estimated separately for patients at high and low risk by using the median of the distribution of the multivariate score as the cut-point. All statistical analyses were performed at Monogram Biosciences (Sperinde, Chappey) and also independently at IDDI (Piette, Buyse).RESULTSCorrelation of HER2 Expression by VeraTag With IHC and FISH Copy NumberData generated at Monogram by using 170 FFPE breast tumor controls show that the VeraTag assay measures subtle differences in HER2 expression that are distributed over a 3-log dynamic range compared with the semiquantitative readout of IHC assessed on a 0 to 3+scale, or by using the more quantitative histoscore (H score), where staining intensity is corrected for percentage of tumor involvement (Shi et al, Fig. 6). By using 19 FFPE metastatic breast tumor control samples obtained from a commercial tissue vendor (MT Group, Santa Monica, CA) and not linked to clinical outcome data, we assessed HER2 gene copy number by FISH by using an independent clinical laboratory (PhenoPath Laboratories, Seattle, WA) and correlated the results with H2T. VeraTag measures of H2T showed a general correlation with total and FISH/CEP17 copy number. However, the data suggest that tumors with similar numbers of HER2 gene copies may express significantly different amounts of HER2 protein (Figs. 1A, B). Similarly, a positive correlation of HER2 expression by the VeraTag assay with FISH/CEP17 copy number in the Bordet cohort was also observed, as shown in Figure 2. Although the correlation with FISH/CEP17 is weaker in the Bordet cohort than in the MT dataset, the sample sizes are small, and the differences may simply reflect the effects of random variation. Larger datasets are needed to gain a better understanding of these relationships.JOURNAL/dimp/04.03/00019606-200903000-00003/figure1-3/v/2021-02-17T200000Z/r/image-jpeg
A and B, VeraTag correlated with FISH. Correlation of HER2 expression by VeraTag with HER2 amplification by total FISH copy number (A), and centromere 17 corrected FISH copy number (B) in 19 FFPE breast cancer controls from the MT Group. FFPE indicates formalin-fixed, paraffin-embedded; FISH, fluorescence in situ hybridization.JOURNAL/dimp/04.03/00019606-200903000-00003/figure2-3/v/2021-02-17T200000Z/r/image-jpeg
VeraTag versus FISH in Bordet. Correlation with centromere 17-corrected FISH copy number in the Bordet cohort (N=64). FISH indicates fluorescence in situ hybridization.Higher Levels of HER2 Expression or HER2 Homodimers Correlate With Better Clinical Outcomes on TrastuzumabSeveral different types of analyses were used to explore the relationship between quantitative levels of HER2 expression or HER2:HER2 dimers and improved outcomes after
trastuzumab treatment. In an analysis of response to trastuzumab by quartiles of H2T or H2D, the relationship between the VeraTag measurements and clinical benefit (CR+PR+SD>6 mo) as assessed by RECIST criteria, although not statistically significant in this small cohort, hint that higher H2T or higher H2D may portend better responses to trastuzumab (test for trend P=0.37 and 0.12, respectively) (Fig. 3).JOURNAL/dimp/04.03/00019606-200903000-00003/figure3-3/v/2021-02-17T200000Z/r/image-jpeg
Clinical benefit by RECIST. Correlation of VeraTag measures of HER2 expression and HER2:HER2 dimers with clinical benefit by RECIST responses in the Bordet cohort (clinical benefit=CR+PR+SD>6 mo). Quartile 1=lowest 25% of HER2 expression/dimer distribution, quartile 4=highest 25% of HER2 expression/dimer distribution. RECIST indicates Response Evaluation Criteria in Solid Tumors.Multivariate Cox proportional hazards regression analyses were performed (Table 2) by using BCS and TTP as end points. In the complete dataset including all 71 patients, 3 prognostic factors were included in the final model after forward selection (Table 2, model A): (1) number of metastatic sites (P=0.00019), (2) HER2 expression by VeraTag (P=0.0058), and (3) treatment with trastuzumab alone (P=0.036). Increasing numbers of metastases and treatment with trastuzumab alone were associated with increased hazard ratios for death, whereas increasing expression of HER2 was associated with a reduced risk of death.JOURNAL/dimp/04.03/00019606-200903000-00003/table2-3/v/2021-02-17T200000Z/r/image-tiff Multivariate Cox Proportional Hazards AnalysesH2T and H2D were strongly correlated in this dataset (r=0.73, P<0.0001). The substitution of H2D for H2T showed a statistically significant correlation with survival (model B). Model C evaluated only the 64 patients who were selected for inclusion by FISH, and found that H2T was still correlated significantly with BCS in this analysis.Cox analyses using TTP as the end point yielded several models that could explain the data. Models obtained by the forward selection procedure included the variable lung metastases and failed to identify H2T (P=0.17) or H2D (P=0.12) as significant prognostic variables. However, when the 3 prognostic factors identified in model A were forced in a model fitted on the TTP data (models D, E), H2T or H2D was correlated with outcome. Model F evaluated only the 64 patients who were selected for inclusion by FISH. Of particular note, 21 patients (30%) were censored early on account of a change in therapy in the absence of progression, perhaps reducing the power of this analysis.KM analyses were performed to examine the relationship between the quantitative levels of H2T or H2D and BCS. In the absence of data suggesting an optimum cutoff, “high” was defined as greater than or equal to the median value of the distribution and “low” as less than the median of the distribution. The left panel of Figure 4A shows the univariate KM plot for H2T. Figure 4C shows the KM plot for the multivariate score based on Model A. Correspondingly, the left panel of Figure 4B shows the univariate KM plot for H2D, and Figure 4D shows the KM plot of the multivariate score based on Model B.JOURNAL/dimp/04.03/00019606-200903000-00003/figure4-3/v/2021-02-17T200000Z/r/image-jpeg
A to F, Kaplan-Meier analyses. Univariate KM plots of BCS and HER2 expression (A) or HER2:HER2 dimers (B). Patients were treated with trastuzumab (H only) or trastuzumab+chemotherapy (H+CT). C and D, Breast cancer survival by multivariate score based on Cox models A and B. E and F, Univariate KM plots in the subpopulation of patients who were treated with trastuzumab alone.In the subgroup of patients treated with trastuzumab alone (N=30), patients with high H2T or H2D survived longer than those in the low group (HR=0.27, P=0.035 for H2T, HR=0.29, P=0.049 for H2D) (Figs. 4E, F).Quantitative Levels of HER2 Expression or HER2:HER2 Dimers and Response to Trastuzumab Alone or in Combination With ChemotherapyFinally, as shown in Figures 4A and B, treatment response seems to differ between patient groups with “high” H2T or H2D and those with “low” H2T or H2D as discriminated by VeraTag. Those in the high group seemed to gain little from the addition of chemotherapy to trastuzumab (see right panels), whereas those in the low group benefited significantly from concomitant chemotherapy and trastuzumab. The interaction test was not statistically significant. There was no correlation between these groupings and estrogen receptor status (data not shown).DISCUSSIONCurrent methodologies employed in the selection of patients with MBC for treatment with trastuzumab are semiquantitative (IHC and FISH) or are indirect measures (FISH) of the expression of the target of trastuzumab, HER2. Only a subset of patients with MBC who are selected to receive trastuzumab based on these assays respond, and a significant percentage of the responders relapse within 1 year.2,10,11,21 In this paper, we describe the initial correlations of HER2 expression and HER2:HER2 dimers, as measured by the VeraTag assay, with clinical outcomes in a well-described cohort of patients with HER2-amplified or overexpressed MBC treated with trastuzumab.These data suggest several interesting interpretations. First, in a cohort of patients considered to be HER2-amplified or HER2-overexpressed on the basis of FISH or IHC, respectively (90% selected by FISH, 10% by IHC with mandatory confirmation of HER2 status and independent review), quantitative measures of HER2 expression or HER2:HER2 dimers, as provided by VeraTag, describe a continuum of response to trastuzumab. The Cox proportional hazards analyses of BCS suggest that higher HER2 expression or HER2:HER2 dimer levels may predict better outcomes after
trastuzumab treatment than lower levels.MBCs that express very high levels of HER2 or HER2:HER2 dimers may be more susceptible to trastuzumab because the signaling cascades that drive their proliferation and survival may be more dependent on associations that are targets of the drug, whereas those tumors that express lower levels of HER2 or have lower levels of HER2:HER2 dimers may derive their proliferative potential from a more heterogeneous set of protein interactions, not all of which are specifically antagonized by trastuzumab. Tumors that are more heterogeneous, from a signaling perspective, may be better equipped to develop resistance to trastuzumab through alternative signaling mechanisms than tumors that are more homogeneously dependent on signaling through protein complexes that are targeted by trastuzumab. Prime candidates that have been hypothesized to explain in vivo reductions in susceptibility to trastuzumab include HER2:HER3 dimers, HER1:HER2 dimers, and p95/HER2 (the constitutively activated, cleaved intracellular domain of HER2), and signaling mediated by non–EGFR-family receptor tyrosine kinases such as IGF-1R.22–33 The identification of such complexes in breast tumors that exhibit clinical resistance to trastuzumab offers the possibility of designing combination therapy trials including trastuzumab and targeted inhibitors of HER1 (eg, erlotinib, gefitinib, lapatinib), HER3 (pertuzumab), or p95/HER2 (lapatinib) for patients whose tumors depend on heterogeneous signaling events for their proliferation and survival. VeraTag assays designed to make these measurements are currently in development.Second, the ability of the VeraTag assay to measure protein dimerization using FFPE specimens is a novel capability, and suggests a way to test the hypothesis that combination therapy regimens selected on the basis of “functional” pathway activation may be more clinically useful than measuring the presence or absence of a particular gene or gene product. In this study, we observed a high correlation between HER2 expression levels and HER2:HER2 dimer levels, and this may reflect the biology of HER2 self-association. It remains to be determined which of these markers is a better predictor of susceptibility to trastuzumab, but it seems likely that the ability to measure HER2 heterodimers may have greater clinical relevance.Third, the observation that patients whose tumors express high levels of HER2 or HER2:HER2 dimers seem to benefit little from the addition of chemotherapy to trastuzumab whereas their counterparts in the lower half of the distribution seem to benefit significantly from combination therapy is potentially important. These data must be interpreted cautiously, as patients were not prospectively randomized to treatment with trastuzumab alone, but rather were selected by their treating oncologists in the course of their individualized clinical management. Although provocative, these data must be considered as hypothesis-generating, and require further investigation in a prospective trial to be confirmed.The clinical impact of these data is uncertain at this time, and more data from larger, well-controlled clinical trials are needed to confirm these observations. However, these findings are novel and potentially important in several respects. Although it would be incorrect to conclude that patients in the low HER2 expression/dimer group are not benefiting from trastuzumab, the data suggest that not all patients selected for trastuzumab therapy by the best currently available methods have the same probability of response and survival. This is consistent with what is already known about clinical outcome after trastuzumab therapy in patients with MBC: not all patients fare equally well on trastuzumab. The VeraTag technology may offer the opportunity to discriminate between groups of patients with different probabilities of clinical response, and to begin to make better decisions regarding their management, as well as to identify patients as appropriate candidates for trastuzumab who may be missed by currently available assays. The knowledge that particular patients have a higher probability of early failure may identify them as better candidates for combination therapy trials than their counterparts who may be unlikely to show demonstrable benefit from the addition of other targeted inhibitors to a trastuzumab-based regimen. In addition, the identification of a subgroup of patients for whom concomitant chemotherapy adds little benefit, and who could be spared the unnecessary risk of toxicity, would be highly desirable. Finally, the ability to use measurements of dimerization events between HER-family receptor tyrosine kinases to characterize reduced susceptibility to trastuzumab, and to identify functionally active protein targets in individual patients, offers hope that the rational design of combination therapy trials for patients with breast cancer may be on the horizon.REFERENCES1. Burstein HJ. The distinctive nature of HER2-positive breast cancers. N Engl J Med. 2005;353:1652–1654.[Context Link][Full Text][CrossRef][Medline Link]2. Cobleigh MA, Vogel CL, Tripathy D, et al. Multinational study of the efficacy and safety of humanized anti-HER2 monoclonal antibody in women who have HER2 overexpressing metastatic breast cancer that has progressed after chemotherapy for metastatic disease. J Clin Oncol. 1999;17:2639–2648.[Context Link][Full Text][CrossRef][Medline Link]3. Eppenberger-Castori S, Kueng W, Benz C, et al. Prognostic and predictive significance of ErbB-2 breast tumor levels measured by enzyme immunoassay. J Clin On-col. 2001;19:645–656.[Context Link][Full Text][CrossRef][Medline Link]4. Slamon DJ, Clark GM, Wong SG, et al. Human breast cancer: correlation of relapse and survival with amplification of the HER-2/neu oncogene. Science (New York, NY). 1987;235:177–182.[Context Link]5. Slamon DJ, Godolphin W, Jones LA, et al. Studies of the HER-2/neu protooncogene in human breast and ovarian cancer. Science (New York, NY). 1989;244:707–712.[Context Link]6. Baselga J, Perez EA, Pienkowski T, et al. Adjuvant trastuzumab: a milestone in the treatment of HER-2-positive early breast cancer. The Oncologist. 2006;11(suppl 1):4–12.[Context Link][CrossRef][Medline Link]7. Hortobagyi GN. Trastuzumab in the treatment of breast cancer. N Engl J Med. 2005;353:1734–1736.[Context Link][Full Text][CrossRef][Medline Link]8. Piccart-Gebhart MJ, Procter M, Leyland-Jones B, et al. Trastuzumab after adjuvant chemotherapy in HER2-positive breast cancer. N Engl J Med. 2005;353:1659–1672.[Context Link][Full Text][CrossRef][Medline Link]9. Romond EH, Perez EA, Bryant J, et al. Trastuzumab plus adjuvant chemotherapy for operable HER2-positive breast cancer. N Engl J Med. 2005;353:1673–1684.[Context Link][Full Text][CrossRef][Medline Link]10. Slamon DJ, Leyland-Jones B, Shak S, et al. Use of chemotherapy plus a mono clonal antibody against HER2 for metastatic breast cancer that overexpresses HER2. N Engl J Med. 2001;344:783–792.[Context Link][Full Text][CrossRef][Medline Link]11. Vogel CL, Cobleigh MA, Tripathy D, et al. Efficacy and safety of trastuzumab as a single agent in first-line treatment of HER2-overexpressing metastatic breast cancer. J Clin Oncol. 2002;20:719–726.[Context Link][Full Text][CrossRef][Medline Link]12. Dressler LG, Berry DA, Broadwater G, et al. Comparison of HER2 status by fluorescence in situ hybridization and immunohistochemistry to predict benefit from dose escalation of adjuvant doxorubicin-based therapy in node-positive breast cancer patients. J Clin Oncol. 2005;23:4287–4297.[Context Link][Full Text][CrossRef][Medline Link]13. Pauletti G, Dandekar S, Rong H, et al. Assessment of methods for tissue-based detection of the HER-2/neu alteration in human breast cancer: a direct comparison of fluorescence in situ hybridization and immunohistochemistry. J Clin Oncol. 2000;18:3651–3664.[Context Link][Full Text][CrossRef][Medline Link]14. Perez EA, Suman VJ, Davidson NE, et al. HER2 testing by local, central, and reference laboratories in specimens from the North Central Cancer Treatment Group N9831 intergroup adjuvant trial. J Clin Oncol. 2006;24:3032–3038.[Context Link][Full Text][CrossRef][Medline Link]15. Press MF, Sauter G, Bernstein L, et al. Diagnostic evaluation of HER-2 as a molecular target: an assessment of accuracy and reproducibility of laboratory testing in large, prospective, randomized clinical trials. Clin Cancer Res. 2005;11:6598–6607.[Context Link][Medline Link]16. Press MF, Slamon DJ, Flom KJ, et al. Evaluation of HER-2/neu gene amplification and overexpression: comparison of frequently used assay methods in a molecularly characterized cohort of breast cancer specimens. J Clin Oncol. 2002;20:3095–3105.[Context Link][Full Text][CrossRef][Medline Link]17. Ross JS, Fletcher JA, Linette GP, et al. The Her-2/neu gene and protein in breast cancer 2003: biomarker and target of therapy. Oncologist. 2003;8:307–325.[Context Link][CrossRef][Medline Link]18. Wolff AC, Hammond ME, Schwartz JN, et al. American Society of Clinical Oncology/College of American Pathologists guideline recommendations for human epidermal growth factor receptor 2 testing in breast cancer. J Clin Oncol. 2007;25:118–145.[Context Link][Full Text][CrossRef][Medline Link]19. Therasse S, Arbuck SG, Eisenhauer E, et al. New guidelines to evaluate the response to treatment in solid tumors. J Natl Cancer Inst. 2000;92:205.[Context Link][Full Text][CrossRef][Medline Link]20. Shi Y, Huang W, Tan Y, et al. A novel proximity assay for the detection of proteins and protein complexes: quantitation of HER1 and HER2 total protein expression and homodimerization in formalin-fixed, paraffin-embedded cell lines and breast cancer tissue. Diagn Mol Pathol. 2009;18:11–21.[Context Link][Full Text][CrossRef][Medline Link]21. Pegram MD, Lipton A, Hayes DF, et al. Phase II study of receptor-enhanced chemosensitivity using recombinant humanized anti-p185HER2/neu monoclonal antibody plus cisplatin in patients with HER2/neu-overexpressing metastatic breast cancer refractory to chemotherapy treatment. J Clin Oncol. 1998;16:2659–2671.[Context Link][Full Text][CrossRef][Medline Link]22. Albanell J, Baselga J. Unraveling resistance to trastuzumab (Herceptin): insulin-like growth factor-I receptor, a new suspect. J Natl Cancer Inst. 2001;93:1830–1832.[Context Link][Full Text][CrossRef][Medline Link]23. DiGiovanna MP, Stern DF, Edgerton SM, et al. Relationship of epidermal growth factor receptor expression to ErbB-2 signaling activity and prognosis in breast cancer patients. J Clin Oncol. 2005;23:1152–1160.[Context Link][Full Text][CrossRef][Medline Link]24. Hendriks BS, Opresko LK, Wiley HS, et al. Coregulation of epidermal growth factor receptor/human epidermal growth factor receptor 2 (HER2) levels and locations: quantitative analysis of HER2 overexpression effects. Cancer Res. 2003;63:1130–1137.[Context Link][Medline Link]25. Holbro T, Beerli RR, Maurer F, et al. The ErbB2/ErbB3 heterodimer functions as an oncogenic unit: ErbB2 requires ErbB3 to drive breast tumor cell proliferation. Proc Natl Acad Sci USA. 2003;100:8933–8938.[Context Link][CrossRef][Medline Link]26. Nahta R, Yu D, Hung MC, et al. Mechanisms of disease: understanding resistance to HER2-targeted therapy in human breast cancer. Nat Clin Pract. 2006;3:269–280.[Context Link]27. Nahta R, Yuan LX, Zhang B, et al. Insulin-like growth factor-I receptor/human epidermal growth factor receptor 2 heterodimerization contributes to trastuzumab resistance of breast cancer cells. Cancer Res. 2005;65:11118–11128.[Context Link][CrossRef][Medline Link]28. Pandolfi PP. Breast cancer—loss of PTEN predicts resistance to treatment. N Engl J Med. 2004;351:2337–2338.[Context Link][Full Text][CrossRef][Medline Link]29. Pinkas-Kramarski R, Soussan L, Waterman H, et al. Diversification of Neu differentiation factor and epidermal growth factor signaling by combinatorial receptor interactions. EMBO J. 1996;15:2452–2467.[Context Link][CrossRef][Medline Link]30. Sergina NV, Rausch M, Wang D, et al. Escape from HER-family tyrosine kinase inhibitor therapy by the kinase-inactive HER3. Nature. 2007;445:437–441.[Context Link][Full Text][CrossRef][Medline Link]31. Slamon DJ. The FUTURE of ErbB-1 and ErbB-2 pathway inhibition in breast cancer: targeting multiple receptors. Oncologist. 2004;9(suppl 3):1–3.[Context Link][CrossRef][Medline Link]32. Yarden Y, Sliwkowski MX. Untangling the ErbB signalling network. Nat Rev. 2001;2:127–137.[Context Link]33. Saez R, Molina MA, Ramsey EE, et al. p95HER-2 predicts worse outcome in patients with HER-2-positive breast cancer. Clin Cancer Res. 2006;12:424–431.[Context Link][Medline Link]HER2 expression; HER2 homodimers; metastatic breast cancer; Cox multivariate analyses; trastuzumab treatment00019606-200903000-0000300006024_2001_344_783_slamon_overexpresses_|00019606-200903000-00003#xpointer(id(citation_FROM_JRF_ID_d1518e942_citationRF_FLOATING))|11065404||ovftdb|SL00006024200134478311065404citation_FROM_JRF_ID_d1518e942_citationRF_FLOATING[Full 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A and B, VeraTag correlated with FISH. Correlation of HER2 expression by VeraTag with HER2 amplification by total FISH copy number (A), and centromere 17 corrected FISH copy number (B) in 19 FFPE breast cancer controls from the MT Group. FFPE indicates formalin-fixed, paraffin-embedded; FISH, fluorescence in situ hybridization.
VeraTag versus FISH in Bordet. Correlation with centromere 17-corrected FISH copy number in the Bordet cohort (N=64). FISH indicates fluorescence in situ hybridization.
Clinical benefit by RECIST. Correlation of VeraTag measures of HER2 expression and HER2:HER2 dimers with clinical benefit by RECIST responses in the Bordet cohort (clinical benefit=CR+PR+SD>6 mo). Quartile 1=lowest 25% of HER2 expression/dimer distribution, quartile 4=highest 25% of HER2 expression/dimer distribution. RECIST indicates Response Evaluation Criteria in Solid Tumors. Multivariate Cox Proportional Hazards Analyses
A to F, Kaplan-Meier analyses. Univariate KM plots of BCS and HER2 expression (A) or HER2:HER2 dimers (B). Patients were treated with trastuzumab (H only) or trastuzumab+chemotherapy (H+CT). C and D, Breast cancer survival by multivariate score based on Cox models A and B. E and F, Univariate KM plots in the subpopulation of patients who were treated with trastuzumab alone.Quantitation of HER2 Expression or HER2:HER2 Dimers and Differential Survival in a Cohort of Metastatic Breast Cancer Patients Carefully Selected for
Trastuzumab Treatment Primarily by FISHDesmedt Christine PhD; Sperinde, Jeff PhD; Piette, Fanny PhD; Huang, Weidong MD, PhD; Jin, Xueguang PhD; Tan, Yuping PhD; Durbecq, Virginie MD, PhD; Larsimont, Denis MD, PhD; Giuliani, Rosa MD, PhD; Chappey, Colombe PhD; Buyse, Marc PhD; Winslow, John PhD; Piccart, Martine MD, PhD; Sotiriou, Christos MD, PhD; Petropoulos, Christos PhD; Bates, Michael MDOriginal ArticlesOriginal Articles118p 22-29
