Abstract OT1-1-12: NSABP FB-7 Trial: A Phase II Randomized Clinical Trial Evaluating Neoadjuvant Therapy Regimens with Weekly Paclitaxel and Neratinib or Trastuzumab or Neratinib and Trastuzumab Followed by Doxorubicin and Cyclophosphamide with Postoperative Trastuzumab in Women with Locally Advanced HER2-Positive Breast Cancer

Neratinib is an oral, small molecule which acts as an irreversible inhibitor of the pan ErbB receptor tyrosine kinase. Dual ErbB blockade combined with chemotherapy improves efficacy in Her-2 positive breast cancer. Both NeoALTTO (Lancet 2012) and Neosphere (Lancet Oncol 2012) trials demonstrated higher pCR for Her-2 positive breast cancer receiving dual anti-Her-2 neoadjuvant blockade therapy. The purpose of this trial is to determine the activity and safety profile of Neratinib as mono-blockade or in combination with Trastuzumab as dual blockade in neoadjuvant therapy of locally advanced breast cancer (stage IIB, III A, B and C).

Methods: This NSABP Foundation Research Program study (FB-7) is designed as a Phase II, multi-center, three arm clinical trial for patients with Her-2 positive locally advanced breast cancer. 126 patients will be enrolled. The initial two- arm study of Neratinib or Trastuzumab in combination with Paclitaxel began in December 2010. 30 patients were enrolled by December of 2011 at which time the study was placed on hold awaiting the recommended phase II dose of the three drug combination, Neratinib, Trastuzamab and Paclitaxel (NSABP FB-8 trial), which is a Phase I dose-escalation study in women with metastatic Her-2 positive breast cancer. The amended FB −7 trial is now a three arm trial of weekly Paclitaxel and Neratinib or Trastuzumab or Neratinib and Trastuzumab for 4 cycles followed by Doxorubicin and Cyclophosphamide for 4 cycles prior to surgical resection. Patients will then receive postoperative Trastuzumb to complete one total year of Her-2 blockade therapy. The primary goal of this study is to determine the pathologic complete response in breast and axillary lymph nodes following completion of neoadjuvant therapy.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr OT1-1-12.

miR-449a regulates the chondrogenesis of human mesenchymal stem cells through direct targeting of lymphoid enhancer-binding factor-1

microRNAs are small molecules, about 17-23 nucleotides in length, that act as translational regulators of their target gene. By binding to a target, microRNAs are known to either inhibit translation or induce degradation of the target. Despite the great interest in microRNAs, however, the exact targets of each individual microRNA in different processes remain largely unknown. In this study, we determined that the lymphoid enhancer-binding factor-1 (LEF-1) was expressed during the chondrogenesis of human bone marrow-derived mesenchymal stem cells (hBM-MSCs) and sought to identify a novel microRNA targeting this gene. Through subsequent studies, we have identified, for the first time, one particular microRNA, miR-449a, that recognizes and regulates the expression of LEF-1 in a dose-dependent and sequence-specific manner. In addition, we observed that the inhibition of LEF-1 via miR-449a led to the subsequent repression of Sox 9, which is a well-established regulator of chondrogenesis. Collectively, this study demonstrated that miR-449a directly targets LEF-1, which in turn affects the expression of Sox 9, ultimately leading to the proper regulation of the differentiation and chondrogenesis of human MSCs (hBM-MSCs).

OT1-02-07: NSABP B-47: A Randomized Phase III Trial of Adjuvant Therapy Comparing Chemotherapy Alone (Six Cycles of Docetaxel Plus Cyclophosphamide or Four Cycles of Doxorubicin Plus Cyclophosphamide Followed by Weekly Paclitaxel) to Chemotherapy Plus Trastuzumab in Women with Node-Positive or High-Risk Node-Negative HER2−Low Invasive Breast Cancer

Adjuvant studies utilizing trastuzumab in early HER2+ breast cancer demonstrated a large reduction in recurrence and death. Post-enrollment central testing showed HER2 non-amplified participants derived similar benefit. Among HER2−amplified patients, multiple studies showed no effect on benefit by degree of amplification. Extensive testing including blinded external review confirmed the non-amplified nature of the HER2 normal group. Detailed relevant background and confirmatory studies will be provided. As a result of these findings, NSABP study B-47, sponsored by the NCI, was activated January 2011. The study is NCI central IRB approved, open in the CTSU, and endorsed by SWOG as of April 2011.

Study: Selection of one of the two chemotherapy regimens is by physician choice: The non-anthracycline regimen is TC (docetaxel 75 mg/m2, cyclophosphamide 600 mg/m2) administered IV every 3 weeks for 6 cycles; the anthracycline regimen is AC followed by WP (doxorubicin 60 mg/m2 and cyclophosphamide 600 mg/m2 administered IV either every 3 weeks or every 2 weeks [per investigator discretion] for 4 cycles followed by paclitaxel 80 mg/m2 IV weekly for 12 doses). Patients will be randomly assigned to receive chemotherapy with or without trastuzumab therapy. For patients receiving the TC chemotherapy regimen, trastuzumab will be given every 3 weeks during and following chemotherapy until 1 year after the first trastuzumab dose (8 mg/kg loading dose; 6 mg/kg for the remaining doses). For patients receiving the AC followed by WP chemotherapy regimen, trastuzumab will begin with the first dose of weekly paclitaxel and will be given weekly for 12 doses (4 mg/kg loading dose; 2 mg/kg for the remaining weekly doses). Following completion of WP, trastuzumab therapy will continue with 6 mg/kg doses given every 3 weeks for a total of 1 year. Patients will also receive adjuvant radiation therapy and endocrine therapy, as clinically indicated.

Detailed menstrual history, concurrent medications, weight changes, and biomarkers (estrogen, stress, inflammation status) will be collected throughout the study. Collection of circulating tumor cells as an ancillary study is planned.

Eligibility: Eligibility includes: node positive or high risk node negative female breast cancer patients; HER2 IHC 1+ or 2+ scores, but non amplified by FISH; normal cardiac, renal, and liver function. Detailed eligibility will be provided.

Statistical: The primary aim is to determine whether the addition of trastuzumab to chemotherapy improves invasive disease-free survival (IDFS). 3260 patients will be enrolled to provide statistical power of 0.9 to detect a 33% reduction in the hazard rate of IDFS using a one-sided alpha level of 0.025. Projected accrual time is approximately 3 years.

Progress: Protocol was activated in January 2011. First patient was entered in February 2011. As of June 16, 2011, 115 of 3260 patients have been enrolled. Supported by NCI U10-12027, -37377, 69651, 69974, and Genentech, Inc.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr OT1-02-07.

Importance of Sox2 in maintenance of cell proliferation and multipotency of mesenchymal stem cells in low-density culture

OBJECTIVES

This study has aimed to repopulate 'primitive' cells from late-passage mesenchymal stem cells (MSCs) of poor multipotentiality and low cell proliferation rate, by simply altering plating density.

MATERIALS AND METHODS

Effects of low density culture compared t high density culture on late-passage bone marrow (BM)-derived MSCs and pluripotency markers of multipotentiality were investigated. Cell proliferation, gene expression, RNA interference and differentiation potential were assayed.

RESULTS AND CONCLUSIONS

We repopulated 'primitive' cells by replating late-passage MSCs at low density (17 cells/cm(2) ) regardless of donor age. Repopulated MSCs from low-density culture were smaller cells with spindle shaped morphology compared to MSCs from high-density culture. The latter had enhanced colony-forming ability, proliferation rate, and adipogenic and chondrogenic potential. Strong expression of osteogenic-related genes (Cbfa1, Dlx5, alkaline phosphatase and type Ι collagen) in late-passage MSCs was reduced by replating at low density, whereas expression of three pluripotency markers (Sox2, Nanog and Oct-4), Osterix and Msx2 reverted to levels of early-passage MSCs. Knockdown of Sox2 and Msx2 but not Nanog, using RNA interference, showed significant decrease in colony-forming ability. Specifically, knockdown of Sox2 significantly inhibited multipotentiality and cell proliferation. Our data suggest that plating density should be considered to be a critical factor for enrichment of 'primitive' cells from heterogeneous BM and that replicative senescence and multipotentiality of MSCs during in vitro expansion may be predominantly regulated through Sox2.

Prediction of late recurrences by breast cancer index in the NCIC CTG MA.17 cohort

2

Background: The MA.17 trial demonstrated that extended adjuvant endocrine therapy with letrozole after 5-y of tamoxifen markedly reduced the risk of recurrence in women with ER+ early stage breast cancer. This trial provides an opportunity to assess the ability of biomarkers to predict late recurrences in ER+ breast cancer. The Breast Cancer Index (BCI), a continuous risk index based on the combination of HOXB13:IL17BR (H:I) and the molecular grade index (MGI), estimates the individual risk of recurrence in ER+ breast cancer patients. In this study, the prognostic utility of BCI to predict late recurrences was examined.

Methods: FFPE tumor blocks were collected from patients who experienced a breast cancer recurrence up to unblinding of MA.17. Controls were matched 2:1 for age, tumor size, nodal status and prior chemotherapy, and were disease free for longer than cases. All cases were reviewed for standard histopathology and evaluated using the real-time RT-PCR BCI assay.

Results: Patient characteristics for the case-control study were similar to that from the overall study. Characteristics for cases (N=83) and controls (N=166) were not significantly different except for treatment. A higher percentage of controls compared to cases tended to be categorized as low risk by BCI (58% vs 43%), while a lower percentage of controls than cases tended to be categorized as high risk by BCI (34% vs 24%). In univariate analysis, treatment, BCI, H:I and HOXB13, but not tumor grade or MGI, were significant predictors of late recurrence. After adjusting for standard variables (age, tumor grade and treatment), BCI (OR 2.37; P=0.03), H:I (OR 2.55; P=0.04) and HOXB13 (OR 1.35; P=0.02) remained significant predictors of recurrence. HOXB13 expression at diagnosis predicted patient benefit from extended endocrine therapy with letrozole.

Conclusions: In this case-controlled study, the data demonstrate that BCI is a significant predictor of late recurrences in ER+ patients following 5-y of tamoxifen. The prognostic performance of BCI to predict late recurrences was largely dependent on HOXB13 expression. The integration of H:I and MGI within BCI provides prognostic utility for both early and late recurrences.

Peroxisome proliferator-activated receptor gamma/signal transducers and activators of transcription 5A pathway plays a key factor in adipogenesis of human bone marrow-derived stromal cells and 3T3-L1 preadipocytes

Adipogenesis is largely dependent on the signal transducers and activators of transcription (STAT) pathway. However, the molecular mechanism of the STAT pathway in the adipogenesis of human bone marrow-derived stromal cells (hBMSCs) remains not well understood. The purpose of this research was to characterize the transcriptional regulation involved in expression of STAT5A and STAT5B during adipogenesis in hBMSCs and 3T3-L1 cells. The expression of STAT5A and STAT5B increases with the onset of adipogenesis in hBMSCs and 3T3-L1 cells. The PPAR response elements regulatory element of STAT5A exists at a promoter region ranging from -346 to -101, and the CCAAT/enhancer-binding protein (C/EBP) regulatory element is located at -196 to -118 of the STAT5B promoter. C/EBPβ and C/EBPα bound to the STAT5B promoter region, whereas peroxisome proliferator-activated receptor γ (PPARγ) bound to STAT5A. RNA interference of STAT5A completely blocked differentiation, whereas the inhibition of STAT5B only partially blocked differentiation. We propose that C/EBPα, C/EBPβ, and PPARγ control adipogenesis by regulating STAT5B and STAT5A and that STAT5A is necessary, whereas STAT5B plays a supplementary role during adipogenesis. Further, the regulation of PPARγ-STAT5 by C/EBPβ signaling seems to be the crucial adipogenesis pathway-initiating cascade of the various adipogenic genes.

Abstract P3-10-26: Quantitative Protein and Gene Expression Biomarkers of Tamoxifen and Letrozole Recurrence in the NCIC CTG MA.17 Cohort

Background: The MA.17 study showed that extended adjuvant endocrine therapy with letrozole (LET) after completing 5 years of tamoxifen (TAM) markedly reduced the risk of recurrence in women with ER+ early stage breast cancer and improved overall survival in women presenting with node +ve disease. The HOXB 13:IL17BR gene expression ratio (signature) has been shown to predict outcome in breast cancer patients treated with adjuvant tamoxifen monotherapy and provides additional information beyond that from known positive (ER and PR) and negative (Her-1 and Her-2) predictors of responsiveness to tamoxifen in node-ve women. We report a case control evaluation of the Breast Cancer Index (BCI; bioTheranostics, Inc.), which combines the HOXB13 and IL17BR twogene and the molecular grade index (MGI) gene expression signatures, with respect to distinguishing which patients are at risk of late recurrences and who would respond to extended endocrine therapy with LET. The prognostic and predictive utility of quantitative immunofluorescence of ER, PR, Her-2, tumor aromatase, COX-2, GATA3 and Nat1 in the TAM-PLACEBO and the TAM-LET cohorts will also be evaluated and compared to results derived by standard immunohistochemistry. Methods: FFPE tumor blocks were collected from patients who experienced a breast cancer recurrence up to unblinding of MA.17. Controls were matched 2:1 for age, tumor size, lymph node status, and prior chemotherapy, and were all disease free for longer than cases. All cases were reviewed for standard histopathology by two independent pathologists. RNA was extracted, amplified, converted to cDNA and subjected to RT-PCR with primers and probes to HOXB13, IL17BR, BUB1A, CENPA, NEK2, RACGAP1 and RRM2. ER, PR HER1, HER2, COX2, Aromatase, GATA3 and NAT1 will be analyzed by routine IHC techniques and by immunoflourescent Automated Quantitative Analysis (AQuA).

Results: 105 cases and 210 matched controls are available for evaluation. All sections are under review and tissue microarrays have been performed on all cases and controls. Detailed results on the BCI and ER, PR, Her-2 will be available at the SABCS.

Discussion: MA.17 has shown that extended adjuvant endocrine therapy after tamoxifen is effective at preventing disease recurrence given for an additional 5 years. Numerous clinical trials are exploring whether extending AIs will show this benefit, and there is an increasing need to improve the therapeutic index by distinguishing those at risk from those who are not. It is also important to determine which patients will benefit from the therapy and which will recur without benefit. The latter patients could be triaged to clinical trials of novel therapies to overcome endocrine resistance. This study will help to define these issues and pave the way for more effective selection of specific patients for adjuvant endocrine strategies.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-10-26.

Clinical Significance of erbB-2 (HER-2/neu) Protein

erbB-2 protein is believed to be a cell membrane receptor for the recently identified ligand gp30. When overexpressed, erbB-2 is an indicator of poor prognosis in adenocarcinomas of breast, stomach, lung, and endometrium. Even more important, clinical data suggest that erbB-2 overexpression may be an indicator of poor response to at least some commonly used adjuvant regimens. However, there is preliminary evidence that these tumors might respond as well to doxorubicin regimen as do erbB-2 negative tumors, at least in gastric cancer. The efficacy of doxorubicin-containing regimen in the treatment of tumors with erbB-2 overexpression needs to be explored further by retrospective analysis of finished clinical trials. Combination of chemotherapeutics with reagents that block erbB-2 signal transduction pathway may be another effective approach.

Correlation of levels of Akt phosphorylation at Ser473 with benefit from paclitaxel chemotherapy in NSABP B-28 patients with node-positive breast cancer

537

Background: We investigated the levels of tumor phospho-Akt(Ser473) (pAkt) and treatment outcome of patients with node-positive breast cancer after adjuvant treatment with doxorubicin/cyclophosphamide (AC) followed by four cycles of paclitaxel (PTX) (AC→PTX) compared with AC chemotherapy alone in the National Surgical Adjuvant Breast and Bowel Project (NSABP) B-28 trial. Methods: The primary tumors on B-28 tissue microarray were available from 1581 of 3060 patients enrolled. pAkt status was examined by immunohistochemistry with the antibody to pAkt(Ser473) (Cell Signaling Technology) at the National Cancer Institute. Levels of pAkt were quantitatively scored with the assistance of an Automated Digital Imaging System blinded to clinical outcome, and categorized by the staining index (intensity X % of staining /100) of > 2 (high) and ≤ 2 (low). The association between tumor pAkt level and clinical outcome at 10 years was assessed using multivariate Cox modeling adjusting for age, tumor size, number of positive nodes, tumor grade, estrogen receptor and HER2 status. Results: Among patients with low tumor pAkt levels (n = 975), there was no DFS difference between those treated with or without PTX (adjusted HR = 1.02, p = 0.81). However, among patients with high tumor pAkt levels (n = 606), those treated with AC→PTX had a 26% reduction in DFS event rate compared to those treated with AC only (adjusted HR = 0.74, p = 0.02). There was no OS difference between treatment groups for those with low pAkt cancer (HR = 0.97, p = 0.80). In patients with high pAkt cancer, those treated with AC→PTX had a 20% reduction in death rate compared to those treated with AC only but this difference did not reach statistical significance (adjusted HR = 0.80, p = 0.17). Conclusions: High levels of Akt phosphorylation at Ser473 independently predict a DFS benefit from the sequential addition of paclitaxel to adjuvant doxorubicin plus cyclophosphamide in node-positive breast cancer. Patients with low levels of pAkt breast cancer may not benefit from the sequential addition of PTX to doxorubicin plus cyclophosphamide.

[Table: see text]

Survival of patients with HER2+ metastatic breast cancer and use of trastuzumab following progression: analysis of RegistHER

Abstract #3142

Background: Most HER2+ metastatic breast cancer (MBC) patients who initially respond to trastuzumab (T)-based therapies will experience disease progression (PD). Standard practice is to discontinue the cytotoxic agent on which disease progressed, however there is evidence that tumors may remain sensitive to HER2 targeting and that there may be a potentiating effect of T on chemotherapy. We examined the treatment history of a large population of HER2+ MBC patients to assess outcomes associated with continuation of T beyond PD.
 Methods: This analysis was carried out on patients enrolled in registHER, a prospective observational study of 1023 patients with newly diagnosed (within 6 months) HER2+ MBC. Median f/u from MBC diagnosis is 25 months at the time of data cut-off (12/31/07). For those treated with T prior to first PD, we compared demographics and baseline tumor characteristics for those patients treated with or without T following first PD. Treatment with T was defined as a minimum of 21 days of therapy prior to PD. In addition, we evaluated time to second PD, and overall survival post PD (both endpoints calculated from initial PD). Overall survival (OS) was also calculated from the date of treatment initiation to death for the entire treated cohort.
 Results: Of 1023 evaluable patients, 873 (85%) were treated with any T-based first-line therapy. 622 T-treated patients progressed and 500 were subsequently treated with T following first PD. Patients who received T post first PD tended to be younger (<50 years of age, 45.2% vs 29.5%) and have hormone receptor positive disease (51.4% vs 42.0%) compared with patients who did not receive T post first PD. Among all treated patients the median overall survival was 35.6 mo (25th-75th-ile:18.6-63.1 mo). Median survival post PD in the 500 patients treated with trastuzumab following first PD was 21.2 mo (25th-75th-ile:11.8-35.8mo).
 Conclusions: OS in patients on the prospective observational study registHER is longer than the OS of 25.1 months noted in the pivotal trial of first-line HER2+ MBC patients treated with T plus chemotherapy. We will present data on the association between various pre- and post-treatment factors, including the use of T beyond PD, and PFS and OS. This will include a multivariate analysis that specifically examines the association between T use in later lines and survival.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3142.

Evaluation of microtubule associated protein tau expression as prognostic and predictive marker in the NSABP-B 28 randomized clinical trial

Abstract #54

Objective: We assessed Tau protein expression in patients who participated in the National Surgical Breast and Bowel Project (NSABP)-B28 clinical trial using immunohistochemistry. Expression levels were correlated with disease-free (DFS) and overall survival (OS) and we also examined if there is interaction between this marker and paclitaxel efficacy. Patients and Methods: Tissue microarrays were available for 1942 patients (63 % of all trial participants) who were included in the NSABP-B28 clinical trial and were randomized to receive either 4 courses of doxorubicin/cyclophosphamide (AC) or AC followed by 4 additional courses of paclitaxel (ACT) adjuvant chemotherapy. All patients with hormone receptor positive tumors also received adjuvant endocrine treatment. Immunohistochemistry for Tau was performed at MD Anderson Cancer Center blinded to clinical outcome. Correlation with survival was performed by the NSABP Statistical Center. Results: Forty-three percent of tumors were Tau-positive defined as equal or greateer staining than in normal breast epithelium. Tau expression correlated strongly with estrogen receptor (ER)-positive status (p<0.0001). In univariate analyses, Tau, ER and HER-2 expression as well as grade, tumor size and nodal status were each independently and significantly associated with DFS and OS (p<0.003). In multivariate analysis, the same variables except HER2 remained significant. However, there was no significant interaction between Tau expression and benefit from paclitaxel in the entire population or among the ER-positive or ER-negative subsets, respectively. Conclusion: High Tau protein expression is associated with better prognosis including longer disease-free and overall survival in patients treated with adjuvant anthracyline and paclitaxel chemotherapy and endocrine therapy. However, we could not detect a statistically significant interaction between Tau expression and paclitaxel benefit.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 54.

Benefit from adjuvant trastuzumab may not be confined to patients with IHC 3+ and/or FISH-positive tumors: Central testing results from NSABP B-31

511

Background: Trastuzumab is a humanized monoclonal antibody targeted to HER2 protein and currently indicated for HER2-positive breast cancer defined by overexpression of HER2 protein (3+ IHC staining by HercepTest™) or HER2 gene amplification (HER2/CEP17 ratio over 2 by PathVysion® FISH assay). These criteria were determined for advanced disease but have not been formally tested in the adjuvant setting. We examined these tests’ ability to predict benefit from adjuvant trastuzumab in NSABP trial B-31. Methods: All available tumor tissue blocks from the B-31 trial were subjected to HercepTest and PathVysion assay as defined in the B-31 protocol. Formal statistical test of interaction between HER2 levels measured by these two tests and benefit from trastuzumab was performed. Results: 207 of 1,795 cases (11.5%) showed gene amplification as determined by PathVysion, and 255 of 1,662 (15.3 %) showed overexpression as determined by HercepTest. 161 of 1,662 (9.7%) had neither gene amplification nor overexpression. There was a consistent benefit from trastuzumab in every subset defined by IHC or FISH. No statistical interaction was found between DFS benefit from trastuzumab and levels of protein (p=0.26) or HER2 gene copy number (p=0.60). Benefit was observed in patients with tumors that were negative for FISH and had less than 3+ staining intensity on IHC by HercepTest (RR=0.36 [CI: 0.14–0.92] p=0.032). Conclusion: Current definition of HER2 overexpression/gene amplification based on data from advanced disease may need to be modified for the adjuvant setting.

[Table: see text]

No significant financial relationships to disclose.

registHER: Patient characteristics, treatment patterns, and preliminary outcomes in patients with HER2-positive (HER2+), hormone receptor-positive (HR+) metastatic breast cancer (MBC)

21007

Background: Approximately 50% of HER2+ breast cancers are HR+, however, the interaction between HER2 and HR is not completely understood. Patients with HR+/HER2+ or HR-/HER2+ tumors treated with trastuzumab + chemotherapy (CT) achieve similar clinical benefit. Retrospective analyses suggest that HER2+ tumors are resistant to hormone therapy (HT), particularly anti-estrogens, possibly due to estrogen receptor /HER2 interactions and quantitatively lower HR expression in HER2+/HR+ tumors. Conducting randomized clinical trials in HER2+/HR+ MBC is challenging given the small patient population. Methods: registHER is a prospective observational study of approximately 1000 patients with newly diagnosed (<6 months) HER2+ MBC treated in community or academic settings. Baseline characteristics and treatment patterns in patients with HR+ vs HR-, HER2+ MBC receiving first-line therapy were studied in this analysis. The influence of adjuvant HT on disease-free intervals (DFI) from time of diagnosis and MBC treatment selection in patients with HR+/HER2+ tumors was examined. Results: Of 976 patients with HER2+ MBC and recorded tumor HR status, those with HR+ MBC (54.9%) tended to be white (81.7% vs 77.0%), were more likely to have bone only metastases (18.1% vs 6.4%), less likely to have CNS metastases (2.8% vs 8.2%), and have fewer metastatic sites at diagnosis (49.1% vs 43.2%) than those with HR- MBC. Of patients with HR+ MBC, who were stage I- III at initial diagnosis, 51.3% received adjuvant HT, of which 73.2% received tamoxifen. Median DFI was 48.8 vs 29.4 mo for patients receiving tamoxifen vs an aromatase inhibitor. First-line MBC treatment regimens included: HT only (13.8%); HT + trastuzumab (8.4%); HT + trastuzumab + CT (6.2%); trastuzumab only (6.0%); CT only (11.0%); trastuzumab + CT (53.5%). Analyses of progression-free survival by HR status and first-line treatments (HT only, trastuzumab ± HT or ± CT), are ongoing and will be described. Conclusions: registHER represents the largest dataset of patients with HER2+/HR+ MBC and provides a unique opportunity to characterize treatment patterns, efficacy and safety, and the natural history of this subset of breast cancer patients.

[Table: see text]

Chemosensitivity and stratification by a five monoclonal antibody IHC test in the NSABP B20 trial

529

Background: We previously reported the association between a five monoclonal antibody test staining p53, NDRG1, SLC7A5, CEACAM5 and HTF9C and recurrence-free interval (RFI) in 711 ER+ N- breast cancer patients from Tamoxifen (Tam) arm of the NSABP trials B14 and B20 (SABCS 2006). In this study, we examined interaction between the test and chemotherapy in the B20 trial. Subjects and Methods: Tissue array sections from B20 paraffin blocks were stained using standard IHC protocols (N=457). Pre-defined scoring rules and cut- points were applied. RFI was defined as time from entry to any local, regional or distant recurrence. Log-rank test was applied to assess the effect of chemotherapy for each risk stratum pre-defined by this IHC test. Interaction between risk strata and treatment was assessed by the likelihood ratio test in a Cox model with age and clinical tumor size adjusted. Results: The IHC test identified high and low risk groups that both showed significant improvement upon treatment with cytotoxic chemotherapy. The moderate risk group was poorly populated and showed no significant difference between chemo-treated and Tam-only patients. Conclusion: It appears that five monoclonal antibodies may be able to identify groups of ER+, node negative patients who have greater absolute benefit from adjuvant Chemo compared to un-stratified patient populations. However, the formal test for interaction between Chemo and the risk group was not significant (p- value=0.127). This may be due to small sample size and a lack of statistical power. The results suggest that this test deserves further evaluation as a method for identifying subsets of patients who may receive more benefit from Chemo.

[Table: see text]

No significant financial relationships to disclose.

Russell body gastritis associated with Helicobacter pylori infection: a case report

An unusual and rare gastric mucosal lesion histologically consisting of a localised accumulation of Russell bodies and Russell body-containing plasma cells, the so-called Mott cells, has been recognised only recently and termed as "Russell body gastritis". This lesion, despite its densely monomorphous appearance is easily confirmed to be non-neoplastic by its polyclonal immunoreactive pattern to immunoglobulin light chains. However, the aetiology of Russell body gastritis is controversial and hence the optimal treatment for this disease has not been established. Two cases of Russell body gastritis associated with Helicobacter pylori infection are reported, and the possible role of H pylori infection in the pathogenesis is discussed.

registHER: Baseline characteristics of a cohort of HER2-positive metastatic breast cancer (MBC) patients

20095

Background: HER2 is amplified in 25% of breast cancers and is associated with poor survival. registHER captures the natural history, treatment patterns and outcomes in 1000 newly-diagnosed HER2-positive MBC patients (pts) throughout the U.S. This observational study recruits pts in both academic and community centers. Methods: This ongoing prospective cohort study collects clinical, pathologic and treatment data at enrollment, quarterly until death, loss to follow-up or 3 years after the last enrollment. We describe baseline pt and clinical characteristics in registHER compared with HER2-positive MBC pts in the phase III pivotal trial (Slamon DJ, et al. N Engl J Med. 2001;344:783–792). Results: Between December 2003 and September 2005, 813 eligible pts were enrolled at 280 study sites. Most pts were seen at community-based (76%) vs academic (18%) clinics; a few pts did not fall into either category (6%). A comparison of baseline characteristics is shown below. Conclusions: registHER pts tended to have a shorter disease-free interval and more estrogen receptor positive disease than pts in the pivotal trial. Reasons for these differences could reflect trial referral and/or diagnostic testing differences. Fewer registHER patients were white, but other characteristics were similar between the two groups. These findings support the hypothesis that observational studies describe a broad patient population which may not exactly duplicate clinical trials. Within registHER, there was some variation between academic vs community clinics (eg. nodal status and adjuvant therapy). Treatment pattern analyses are ongoing.

[Table: see text]

[Table: see text]