Armelle Degeorges

A New Model of Patient Tumor-Derived Breast Cancer Xenografts for Preclinical Assays

Purpose: To establish a panel of human breast cancer (HBC) xenografts in immunodeficient mice suitable for pharmacologic preclinical assays. Experimental Design: 200 samples of HBCs were grafted into Swiss nude mice. Twenty-five transplantable xenografts were established (12.5%). Their characterization included histology, p53 status, genetic analysis by array comparative genomic hybridization, gene expression by Western blotting, and quantitative reverse transcription-PCR. Biological profiles of nine xenografts were compared with those of the corresponding patients tumor. Chemosensitivities of 17 xenografts to a combination of Adriamycin and cyclophosphamide (AC), docetaxel, trastuzumab, and Degarelix were evaluated. Results: Almost all patient tumors established as xenografts displayed an aggressive phenotype, i.e., high-grade, triple-negative status. The histology of the xenografts recapitulated the features of the original tumors. Mutation of p53 and inactivation of Rb and PTEN proteins were found in 83%, 30%, and 42% of HBC xenografts, respectively. Two HBCx had an ERBB2 (HER2) amplification. Large variations were observed in the expression of HER family receptors and in genomic profiles. Genomic alterations were close to those of original samples in paired tumors. Three xenografts formed lung metastases. A total of 15 of the 17 HBCx (88%) responded to AC, and 8 (47%) responded to docetaxel. One ERBB2-amplified xenograft responded to trastuzumab, whereas the other did not. The drug response of HBC xenografts was concordant with that of the patients tumor in five of seven analyzable cases. Conclusions: This panel of breast cancer xenografts includes 15 triple-negative, one ER positive and 2 ERBB2 positive. This panel represents a useful preclinical tool for testing new agents and protocols and for further exploration of the biological basis of drug responses.

Clinical value of circulating endothelial cells and circulating tumor cells in metastatic breast cancer patients treated first line with bevacizumab and chemotherapy

BACKGROUND We investigated whether circulating tumor cells (CTCs) and circulating endothelial cells (CECs) predict clinical outcome of first-line chemotherapy combined with bevacizumab in metastatic breast cancer patients. PATIENTS AND METHODS In a French substudy of the MO19391 trial, CTC and CEC counts (CellSearch system) at baseline and changes after two cycles of treatment were correlated with time to progression (TtP). RESULTS CTC and CEC levels were not correlated in the 67 patients included. At baseline, CTC positivity was a significant prognostic marker for TtP at a threshold of 3 CTC/7.5 ml (P < 0.05) but not at 5 CTC/7.5 ml (P = 0.09). Baseline CEC levels (median 17 CEC/4 ml, range 1-769) were associated with age > or =45 years (P = 0.01), elevated lactate dehydrogenase (P < 0.01) and not with TtP at any threshold. Changes of CTC count during treatment were not a surrogate of TtP, with any of the model tested (threshold based or relative decrease in percent). However, increase in CEC count was associated with improved TtP, at the threshold of 20 CEC/4 ml (P < 0.01). CONCLUSION Bevacizumab combined with first-line chemotherapy may modify the predictive value of CTC during treatment possibly due to impaired tumor cells intravasation through vessels endothelium. Variations in CEC levels appear to be a promising early surrogate marker of TtP under antiangiogenic treatment.

Prospective analysis of the impact of VEGF-A gene polymorphisms on the pharmacodynamics of bevacizumab-based therapy in metastatic breast cancer patients.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • Functional polymorphisms on the VEGF-A gene, known to be linked to cancer risk or to VEGF-A plasma concentrations, have been identified. So far, limited knowledge has been published on the relationships between toxicity/efficacy of bevacizumab-based therapy and VEGF-A polymorphisms (tumoral DNA). We therefore prospectively tested the impact of these five gene polymorphisms (blood DNA) on the pharmacodynamics of bevacizumab-based treatment administered in metastatic breast cancer patients. WHAT THIS STUDY ADDS • Present data obtained from a prospective study suggest a role for VEGF-A 936C > T polymorphism as a potential predictor of time to progression in breast cancer patients receiving bevacizumab-containing therapy. Also, the VEGF-A-634G > C polymorphism was linked to bevacizumab-related toxicity. AIMS To test prospectively the impact of VEGF-A gene polymorphisms on the pharmacodynamics of bevacizumab-chemotherapy in breast cancer patients. METHODS As part of the single-arm MO19391 trial, 137 women with locally recurrent or metastatic breast cancer receiving first-line bevacizumab-containing therapy were analysed. Patients received bevacizumab associated (76%) or not (24%) with taxane-based chemotherapy. Clinical evaluation included clinical response, time to progression (TTP) and a toxicity score corresponding to the sum of each maximum observed toxicity grade (hypertension, haemorrhage, arterial and venous thrombo-embolism). Functional VEGF-A polymorphisms at position -2578 C > A, -1498 T > C, -1154 G > A, -634 G > C and 936 C > T were analysed by PCR-RFLP (blood DNA). RESULTS Overall response rate (complete response (CR) + partial response (PR)) was 61%. Median TTP was 11 months. None of the VEGF-A polymorphisms was significantly linked to clinical response. Analysis of the 936C > T polymorphism revealed that the 96 patients homozygous for the 936C allele exhibited a marked tendency for a shorter TTP (median 9.7 months) than the 32 patients bearing the 936T allele (median 11.5 months, P= 0.022) of which 30 were CT and two were homozygous TT. Other polymorphisms did not influence TTP. VEGF-A-634 G > C was significantly related to the toxicity score with 39%, 49% and 81% of patients with score >1 in GG, GC and CC patients, respectively (P= 0.01). CONCLUSIONS The role for VEGF-A 936C > T polymorphism as a potential marker of TTP in breast cancer patients receiving bevacizumab-containing therapy concords with the known impact of VEGF-A 936C > T polymorphism on VEGF-A expression.

Is p53 a protein that predicts the response to chemotherapy in node negative breast cancer

The role of p53 in modulating apoptosis has suggested that it may affect efficacy of anti cancer agents. For this reason, we have evaluated p53 alterations in 282 consecutive patients with infiltrating node-negative breast cancer who underwent primary surgery and were randomized either to CMF (Cyclophosphamide 400 mg/m2, Fluorouracil 400 mg/m2, and Methotrexate 40 mg/m2) or control arm (no adjuvant therapy) from 1980 to 1989. p53 alterations were analyzed by immunohistochemistry using DO7 MoAb, revealed by immunoperoxidase technique, and quantitated in term of percentage of positive cells. We observed a positive staining in 24% of the tumors. Among them, 10% had a positive staining in more than 75% of the cells. There was a highly significant association between the proportion of positive cells and histologic grade of the infiltrating ductal carcinomas (p > 0.004). However, there was no association with age, tumor size, hormone receptor content, or vascular embolism. There was a trend but no significant relationship between positive staining and overall survival either in each arm of the trial or in the overall population. Interestingly, we observed a higher relative risk of local relapse after conservative therapy in the boosted area in the group of mutated p53 (RR = 4.41; p > 0.0005). We conclude that, in this node-negative breast tumor population, alteration of p53 cannot predict the response to the chemotherapy. However, it may represent a useful marker of risk of local relapse and of radio resistance.

Tumor aromatase expression as a prognostic factor for local control in young breast cancer patients after breast-conserving treatment

IntroductionWe sought to determine whether the levels of expression of 17 candidate genes were associated with locoregional control after breast-conserving treatments of early-stage breast cancers in young, premenopausal women.MethodsGene expression was measured by using RT-PCR in the breast tumors of a series of 53 young (younger than 40 years), premenopausal patients. All treatments consisted of primary breast-conserving surgery followed by whole-breast radiotherapy (± regional lymph nodes) with or without systemic treatments (chemotherapy ± hormone therapy). The median follow-up was 10 years.ResultsThe 10-year locoregional control rate was 70% (95% CI, 57% to 87%). In univariate analysis, no clinical/pathologic prognostic factors were found to be significantly associated with decreased locoregional control. Expression of three genes was found to be significantly associated with an increased locoregional recurrence rate: low estrogen-receptor β, low aromatase, and high GATA3. Two others were associated with only a trend (P < 0.10): low HER1 and SKP2. In multivariate analysis, only the absence of aromatase was significantly associated with an increased locoregional recurrence rate (P = 0.003; relative risk = 0.49; 95% CI 0.29 to 0.82).ConclusionsRecent data give credit to the fact that breast cancer in young women is a distinct biologic entity driven by special oncogenic pathways. Our results highlight the role of estrogen-signaling pathways (mainly CYP19/aromatase, GATA3, and ER-β) in the risk of locoregional recurrence of breast cancer in young women. Confirmation in larger prospective studies is needed.

Abstract 2751: Impact of germinal vascular endothelial growth factor-A (VEGF-A) gene polymorphisms on pharmacodynamics of bevacizumab in metastatic breast cancer patients treated as first-line therapy : A French companion study of the open label international multicenter MO19391 trial

Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC Background: VEGF-A expression is a marker of invasiveness and tumor progression in various cancer, including breast cancer. The aim of this prospective companion study was to test the impact of the 5 major functional VEGF-A gene polymorphisms on bevacizumab pharmacodynamics in breast cancer patients. Methods: MO19391 (ATHENA) is a single-arm, prospective, international safety study, conducted in 2296 patients treated with first-line bevacizumab-containing therapy in the context of general oncology practice. A companion study was conducted in 27 French centers to evaluate VEGF-A polymorphisms as potential predictors of treatment efficacy and safety. A total of 143 women with locally recurrent or metastatic breast cancer were enrolled in this pharmacogenetic study. Patients (mean age 54.8, 64% ECOG PS 0) received bevacizumab (10 mg/kg q2w or 15 mg/kg q3w), associated (76 %) or not (24 %) with a taxane-based chemotherapy, until disease progression, unacceptable toxicity or withdrawal. Median duration of bevacizumab treatment was 29 weeks. Median follow-up was 16 months. Clinical end-points were clinical response (complete response (CR) + partial response (PR)), time to progression (TTP) and toxicity. Functional VEGF-A polymorphisms at position −2578 C>A, −1498 T>C, −1154 G>A, −634 G>C and 936 C>T were analyzed by PCR-RFLP in blood DNA. Results: Overall response rate (CR+PR) was 60.5 % and median TTP was 11 months. None of the analyzed VEGF-A polymorphisms was significantly linked to clinical response. In contrast, analysis of the 936C>T polymorphism revealed that the 102 patients homozygous for the 936C allele exhibited a significantly shorter TTP than the 32 patients bearing the 936T allele (Log Rank, p = 0.019) of which 30 were CT and 2 were homozygous TT. Median TTP was 9.0 months (CI 95% 7.6-12) in CC patients vs 11.5 months (CI 95% 10.2-25.8) in CT or TT patients. Other polymorphisms did not influence TTP. Analysis of bevacizumab-related toxicity is ongoing. Conclusion: The present results suggest a role for VEGF-A 936C>T polymorphism as a potential marker of bevacizumab efficacy. This observation concords with the impact of VEGF-A 936C>T polymorphism - located in the 3′untranslated region of the gene - on VEGF-A expression since lower plasma and tumoral VEGF-A concentrations have been reported in patients harboring the VEGF-A 936T allele. Further studies aimed at confirming the influence of VEGF-A 936C>T genotype are warranted. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2751.

Tumour Aromatase Expression, a Prognostic for Local Control in Young Breast Cancer Patients after Breast-Conserving Treatment?

Introduction: To determine whether the levels of expression of 17 candidate genes were associated with locoregional control after breast conserving treatments of early-stage breast cancers in young, premenopausal women.Methods: Gene expression was measured using RT-PCR in the breast tumors of a series of 53 young (≤40 years), premenopausal patients. All treatments consisted in primary breast conserving surgery followed by whole-breast radiotherapy (+/- regional lymph nodes) with or without systemic treatments (chemotherapy +/- hormone-therapy). The median follow-up was 10 years.Results: The 10-year locoregional recurrence rate was 70% (95% CI 57%-87%). In univariate analysis, no clinical/pathological prognostic factors were found to be significantly associated with a decreased loco-regional control. Expression of three genes was found to be significantly associated with an increased loco-regional recurrence rate: low estrogen receptor beta, low aromatase, high GATA3. Two others were associated with only a trend (p Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6035.