Estrogen receptor, Progesterone receptor, HER2 status and Ki67 index and responsiveness to adjuvant tamoxifen in postmenopausal high-risk breast cancer patients enrolled in the DBCG 77C trial.

BACKGROUND: The DBCG 77C trial compared one year of tamoxifen in postmenopausal, steroid-receptor unknown, high-risk breast cancer patients to no adjuvant systemic therapy. After a potential follow-up of 30years we report overall efficacy of the study and results according to subtypes subsequently assessed by immunohistochemistry and fluorescent in situ hybridisation (FISH). METHODS: Between 1977 and 1982, 1716 postmenopausal patients with tumours larger than 5cm or positive axillary nodes were randomly assigned to no systemic therapy or tamoxifen 30mg daily for one year. Archival tumour tissue from 1515 patients was analysed and the hormone receptor positive (estrogen receptor (ER) and/or progesterone receptor (PR)) cancers were defined as luminal A if Ki67 low and HER2-negative; as luminal B if Ki67 high or HER2-positive; and otherwise as non-luminal-HER2 positive or triple negative. FINDINGS: In the intent-to-treat (ITT) population one year of tamoxifen improved the disease-free-survival (DFS) (hazard ratio (HR)=0.87; 95% confidence interval (CI) 0.77-0.98), the Breast Cancer Recurrence Rate (BCRR) (HR=0.79; 0.69-0.90) and reduced the breast-cancer-specific-mortality (BCM) (HR=0.83; 0.73-0.93). BCRR were improved significantly by tamoxifen in luminal A (HR=0.66; 0.53-0.84) and luminal B/HER2- (HR=0.54; 0.39-0.74) but not in the other subsets, and with similar results for BCM with 30years follow-up. INTERPRETATION: One year of treatment with tamoxifen significantly improves BCRR and BCM in postmenopausal patients with ER positive breast cancers. The relative benefit from tamoxifen was not significantly different in luminal A and B subtypes. FUNDING: The Danish Breast Cancer Cooperative Group (DBCG) prepared the original protocol (DBCG 77C) and was the sponsor of the study. Funding was not provided to the participating departments. The biomarker study was supported by grants from the Clinical Institute, Odense University.

Gene aberrations of RRM1 and RRM2B and outcome of advanced breast cancer after treatment with docetaxel with or without gemcitabine.

BACKGROUND: The purpose of the present study was to retrospectively evaluate whether copy number changes of the genes encoding the ribonucleotide reductase subunit M1 (RRM1) and/or subunit M2B (RRM2B) predict sensitivity to gemcitabine administered in combination with docetaxel compared to single agent docetaxel in advanced breast cancer patients. METHODS: Primary tumor samples from patients randomly assigned to gemcitabine plus docetaxel or docetaxel alone were analyzed for RRM1 and RRM2B copy number changes using Fluorescence In Situ Hybridization (FISH) technology with probes covering respectively RRM1 at 11p15.5 and a reference probe covering the centromere of chromosome 11 (CEN-11), and RRM2B at 8q22.3 and a reference probe covering the centromere of chromosome 8 (CEN-8). The assays were validated in a material of 60 normal breast samples. Time to progression (TTP) was the primary endpoint. Overall survival (OS) and response rate (RR) were secondary endpoints. Associations between RRM1/CEN-11 and/or RRM2B/CEN-8 ratios and time-to-event endpoints were analyzed by unadjusted and adjusted Cox proportional hazards regression models. Heterogeneity of treatment effects on TTP and OS according to gene status were investigated by subgroup analyses, and the Wald test was applied. All statistical tests were two-sided. RESULTS: FISH analysis for both RRM1 and RRM2B was successful in 251 patients. RRM1 and RRM2B aberrations (deletions and amplifications) were observed in 15.9% and 13.6% of patients, respectively. RRM1 aberrations were associated with a decreased OS in the time interval 1.5-7.4 years (hazard ratio = 1.72, 95% confidence interval = 1.05-2.79, P = 0.03). RRM2B aberrations alone or in combination with RRM1 aberrations had no prognostic impact in terms of TTP or OS. RR was not different by gene status. No significant differences were detected in TTP or OS within subgroups according to gene status and chemotherapy regimen. CONCLUSIONS: This study demonstrated the presence of RRM1 and RRM2B copy number changes in primary breast tumor specimens. Nevertheless, we found no support of the hypothesis that aberrations of RRM1 or RRM2B, neither individually nor in combination, are associated with an altered clinical outcome following chemotherapy with gemcitabine in combination with docetaxel compared to docetaxel alone in advanced breast cancer patients.

HER2, TOP2A, and TIMP-1 and responsiveness to adjuvant anthracycline-containing chemotherapy in high-risk breast cancer patients.

PURPOSE To evaluate whether the combination of HER2 with TIMP-1 (HT) or TOP2A with TIMP-1 (2T) more accurately identifies patients who benefit from cyclophosphamide, epirubicin, and fluorouracil (CEF) compared with cyclophosphamide, methotrexate, and fluorouracil (CMF) than these markers do when analyzed individually. PATIENTS AND METHODS The Danish Breast Cancer Cooperative Group (DBCG) 89D trial randomly assigned 980 high-risk Danish breast cancer patients to CMF or CEF. Archival tumor tissue was analyzed TIMP-1, and HER2-negative and TIMP-1 immunoreactive tumors were classified as HT nonresponsive and otherwise HT responsive. Similarly, the 2T panel was constructed by combining TOP2A and TIMP-1; tumors with normal TOP2A status and TIMP-1 immunoreactivity were classified as 2T-nonresponsive and otherwise 2T-responsive. Results In total, 623 tumors were available for analysis, of which 154 lacked TIMP-1 immunoreactivity, 188 were HER2 positive, and 139 had a TOP2A aberration. HT status was a statistically significant predictor of benefit from CEF compared with CMF (P(interaction) = .036 for invasive disease-free survival [IDFS] and .047 for overall survival [OS]). The 269 (43%) patients with a 2T-responsive profile had a significant reduction in IDFS events (adjusted hazard ratio, 0.48; 95% CI, 0.34 to 0.69; P < .001) and OS events (adjusted hazard ratio, 0.54; 95% CI, 0.38 to 0.77; P < .001). 2T status was a highly significant predictor of benefit from CEF compared with CMF (P(interaction) < .0001 for IDFS and .004 for OS). CONCLUSION The 2T profile is a more accurate predictor of incremental benefit from anthracycline-containing chemotherapy than HER2, TIMP-1, or TOP2A individually, and compared with these, 2T classifies a larger proportion of patients as sensitive to anthracyclines.

Amplified in breast cancer 1 in human epidermal growth factor receptor - positive tumors of tamoxifen-treated breast cancer patients.

PURPOSE: Amplified in breast cancer 1 (AIB1) is a member of the p160/steroid receptor coactivators family and is involved in estrogen-dependent gene transcription by reducing the antagonistic activity of tamoxifen-bound estrogen receptor-alpha (ER-alpha). The present study was carried out to test the hypothesis that AIB1 protein expression and/or gene amplification mediates tamoxifen resistance in breast cancer. EXPERIMENTAL DESIGN: Immunohistochemistry using AIB1 antibody and fluorescence in situ hybridization using probes specific for AIB1 and chromosome 20 was done on 402 ER-alpha-positive tamoxifen-treated breast cancers. RESULTS: AIB1 overexpression was not associated with relapse during treatment with tamoxifen. In contrast, high AIB1 expression in patients with human epidermal growth factor receptor (HER) 2- and HER3-overexpressing tumors or tumors expressing one or more of HER1, HER2, or HER3 (HER1-3 positive) was associated with an increased risk of relapse on tamoxifen [hazard ratio, 2.20; 95% confidence interval, 1.07-3.52 (P = 0.0416); hazard ratio, 2.42; 95% confidence interval, 1.32-4.43 (P = 0.0030), respectively]. AIB1 gene amplification was observed in 18 of 362 (5%) patients. High AIB1 gene copy number had no effect on overall or disease-free survival. CONCLUSIONS: Data presented here support a role for AIB1 expression on relapse during tamoxifen treatment in hormone-responsive HER-expressing clinical breast cancers and support clinical evidence, suggesting a cross-talk between ER-alpha and growth factor receptor pathways through changes in expression of specific coactivator proteins, such as AIB1. This study highlights the potential that tumor profiling, using multiple markers of treatment response, may improve patient selection for endocrine treatment, such as tamoxifen or aromatase inhibitors.

retrospective analysis of topoisomerase IIa amplifications and deletions as predictive markers in primary breast cancer patients randomly assigned to cyclophosphamide, methotrexate, and fluorouracil or cyclophosphamide, epirubicin, and fluorouracil: Danish Breast Cancer Cooperative Group.

PURPOSE: The aim of the study was to evaluate the predictive value of HER2 and topoisomerase IIalpha gene (TOP2A) for the efficacy of epirubicin in the adjuvant setting of breast cancer patients. PATIENTS AND METHODS: In the Danish Breast Cancer Cooperative Group trial 89D, 980 pre- and postmenopausal primary patients were randomly allocated to either CMF (cyclophosphamide, methotrexate, and fluorouracil; n = 500) or CEF (cyclophosphamide, epirubicin, and fluorouracil; n = 480) times 9, between January 1990 and November 1999. Tumor tissue was retrospectively identified from 805 patients and was analyzed for HER2-positivity and for TOP2A-amplifications and deletions. RESULTS: HER2-positivity was found in 33% of the 805 investigated tumors and was not a predictive marker for epirubicin sensitivity. TOP2A changes were identified in 23% of the 773 investigated tumors: 12% had TOP2A amplifications and 11% had TOP2A deletions. We found that patients with TOP2A amplification had an increased recurrence-free (RFS; hazard ratio [HR], 0.43; 95% CI, 0.24 to 0.78) and overall survival (OS; HR, 0.57; 95% CI, 0.29 to 1.13), respectively if treated with CEF compared with CMF, and that patients with TOP2A deletions had an almost identical hazard ratio (RFS: HR, 0.63; 95% CI, 0.36 to 1.11; OS: HR, 0.56; 95% CI, 0.30 to 1.04). This is in contrast to patients with a normal TOP2A genotype for whom similar outcome was observed in both treatment arms (RFS: HR, 0.90; 95% CI, 0.70 to 1.17; OS: HR, 0.88; 95% CI, 0.66 to 1.17). CONCLUSION: TOP2A amplification-and possibly deletion-seems to be predictive markers for the effect of adjuvant epirubicin containing therapy in primary breast cancer, but a final conclusion has to await a confirmative study or a meta-analysis.

Amplification of HER2 and TOP2A and deletion of TOP2A genes in breast cancer investigated by new FISH probes.

New strategies for improving treatment of patients with breast carcinoma have focused on the HER2 oncoprotein with regard to response to traditional therapy regimes and the effect of a new drug specifically directed against the protein. Furthermore, the status of the topoisomerase IIalpha (TOP2A) gene has been suggested as a predictive marker of anthracycline treatment. In this study of 120 tumours, immunohistochemically detected HER2 overexpression with HercepTest has been compared to the HER2 gene amplification investigated with a new HER2 probe for fluorescence in situ hybridization (FISH). In addition, the HercepTest was evaluated as a screening tool for choosing cases for FISH investigation of TOP2A gene aberrations. The HercepTest score 3+ identified HER2 gene amplification in 27 of 30 amplified tumours (sensitivity of 0.90) with a false-negative rate of 0.10 and a false-positive rate of 0.06. TOP2A gene amplification or deletion was found in 20 cases. Sixteen (80%) of these carcinomas were in the HercepTest 3+ group, but four tumours had alterations in the TOP2A gene with normal HER2 status. Traditionally, in the FISH technique the result has been based on counting 60 cells. However, we found that a much less time-consuming method of counting 60 signals gave equally good results.