Florence Dalenc

Lapatinib plus capecitabine in patients with previously untreated brain metastases from HER2-positive metastatic breast cancer (LANDSCAPE): a single-group phase 2 study

BACKGROUND Brain metastases occur in 30-50% of patients with metastatic HER2-positive breast cancer. In the case of diffuse brain metastases, treatment is based on whole brain radiotherapy (WBRT). Few systemic options are available. We aimed to investigate the combination of lapatinib plus capecitabine for the treatment of previously untreated brain metastases from HER2-positive breast cancer. METHODS In this single-arm phase 2, open-label, multicentre study, eligible patients had HER2-positive metastatic breast cancer with brain metastases not previously treated with WBRT, capecitabine, or lapatinib. Tretament was given in 21 day cycles: patients received lapatinib (1250 mg, orally) every day and capecitabine (2000 mg/m(2), orally) from day 1 to day 14. The primary endpoint was the proportion of patients with an objective CNS response, defined as a 50% or greater volumetric reduction of CNS lesions in the absence of increased steroid use, progressive neurological symptoms, and progressive extra-CNS disease. All responses had to be confirmed 4 weeks after initial response. Efficacy analyses included all patients who received the study drugs and were assessable for efficacy criteria. This trial is registered with ClinicalTrials.gov, number NCT00967031. FINDINGS Between April 15, 2009, to Aug 2, 2010, we enrolled 45 patients, 44 (98%) of whom were assessable for efficacy, with a median follow-up of 21·2 months (range 2·2-27·6). 29 patients had an objective CNS response (65·9%, 95% CI 50·1-79·5); all were partial responses. Of all 45 treated patients, 22 (49%) had grade 3 or grade 4 treatment-related adverse events, of which the most common were diarrhoea in nine (20%) patients and hand-foot syndrome in nine (20%) patients. 14 (31%) patients had at least one severe adverse event; treatment was discontinued because of toxicity in four patients. No toxic deaths occurred. INTERPRETATION The combination of lapatinib and capecitabine is active as first-line treatment of brain metastases from HER2-positive breast cancer. A phase 3 trial is warranted. FUNDING GlaxoSmithKline-France and UNICANCER.

Widespread Estrogen-Dependent Repression of microRNAs Involved in Breast Tumor Cell Growth

Altered expression of microRNAs (miRNA), an abundant class of small nonprotein-coding RNAs that mostly function as negative regulators of protein-coding gene expression, is common in cancer. Here, we analyze the regulation of miRNA expression in response to estrogen, a steroid hormone that is involved in the development and progression of breast carcinomas and that is acting via the estrogen receptors (ER) transcription factors. We set out to thoroughly describe miRNA expression, by using miRNA microarrays and real-time reverse transcription-PCR (RT-PCR) experiments, in various breast tumor cell lines in which estrogen signaling has been induced by 17beta-estradiol (E(2)). We show that the expression of a broad set of miRNAs decreases following E(2) treatment in an ER-dependent manner. We further show that enforced expression of several of the repressed miRNAs reduces E(2)-dependent cell growth, thus linking expression of specific miRNAs with estrogen-dependent cellular response. In addition, a transcriptome analysis revealed that the E(2)-repressed miR-26a and miR-181a regulate many genes associated with cell growth and proliferation, including the progesterone receptor gene, a key actor in estrogen signaling. Strikingly, miRNA expression is also regulated in breast cancers of women who had received antiestrogen neoadjuvant therapy. Overall, our data indicate that the extensive alterations in miRNA regulation upon estrogen signaling pathway play a key role in estrogen-dependent functions and highlight the utility of considering miRNA expression in the understanding of antiestrogen resistance of breast cancer.

RhoB controls the 24 kDa FGF-2-induced radioresistance in HeLa cells by preventing post-mitotic cell death.

Farnesylated Ras oncoprotein induces a cellular resistance to ionizing radiation that can be reversed by farnesyltransferase inhibitors (FTI). We previously demonstrated that, expression of the 24 kDa FGF2 isoform in wild type ras bearing HeLa cells, induced radioresistance which was also reversed by FTI. We tested the hypothesis that wild type Ras or RhoB, which has been proposed as a potential FTI target, could control the FGF-2-induced radioresistance mechanisms. For this, we expressed inducible dominant negative forms of Ras (RasN17) and Rho (RhoBN19) in 24 kDa FGF2 transfected HeLa cells and analysed their survival after irradiation. While no cell survival modification was observed after RasN17 induction, the expression of RhoBN19 induced a radiosensitization of FGF2 radioresistant HeLa cells in the same range as the one observed after a 48 h treatment with the specific FTI, R115777. Moreover, we showed that activated RhoB but not RhoA induced radioresistance in NIH3T3 cells. The radiosensitizer effect of RhoBN19 expression was due to the induction of the radiation induced post-mitotic cell death. Taken together, these data demonstrate that 24 kDa FGF-2-induced radioresistance is controlled by Rho pathways and suggest that RhoB should be a major determinant in cellular resistance to ionizing radiation.

Dendrogenin A arises from cholesterol and histamine metabolism and shows cell differentiation and anti-tumour properties

We previously synthesized dendrogenin A and hypothesized that it could be a natural metabolite occurring in mammals. Here we explore this hypothesis and report the discovery of dendrogenin A in mammalian tissues and normal cells as an enzymatic product of the conjugation of 5,6α-epoxy-cholesterol and histamine. Dendrogenin A was not detected in cancer cell lines and was fivefold lower in human breast tumours compared with normal tissues, suggesting a deregulation of dendrogenin A metabolism during carcinogenesis. We established that dendrogenin A is a selective inhibitor of cholesterol epoxide hydrolase and it triggered tumour re-differentiation and growth control in mice and improved animal survival. The properties of dendrogenin A and its decreased level in tumours suggest a physiological function in maintaining cell integrity and differentiation. The discovery of dendrogenin A reveals a new metabolic pathway at the crossroads of cholesterol and histamine metabolism and the existence of steroidal alkaloids in mammals.

HFS-14, a Specific Quality of Life Scale Developed for Patients Suffering from Hand–Foot Syndrome

BACKGROUND Hand-foot syndrome (HFS) is a common reaction to certain chemotherapies and new targeted therapies, impairing patient quality of life (QoL). However, there is currently no specific tool to measure QoL in patients with HFS. Objective. The objective was to develop and validate a HFS-specific QoL questionnaire (HFS-14). PATIENTS AND METHODS From a list of 31 items identified from a literature review and patient interview notes, item reduction and pilot testing by cognitive debriefing resulted in a final 14-item questionnaire with excellent internal reliability. Clinical validity was assessed in 43 patients with HFS by comparing the HFS-14 score according to HFS clinical grade based on the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE), version 3.0, and by measuring its correlation with the Dermatology Life Quality Index (DLQI), Skindex-16, and short-form 12 health-related questionnaires and pain measurement. RESULTS The mean HFS-14 score was significantly higher in patients with clinical grade 2 and grade 3 HFS than in those with grade 1 HFS. The higher the HFS-14 score, the greater the QoL impairment. The HFS-14 score was highly correlated with the DLQI and Skindex-16 scores. In the population of patients with severe grade 3 NCI-CTCAE HFS, the HFS-14 score was significantly higher in patients having both hands and feet severely involved than in those with severe involvement of one limb (hands or feet) with the other one less severely affected. CONCLUSIONS This scale specifically developed for patients with HFS is a valid and valuable tool for measuring HFS-related QoL impairment.

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.

Importance of cholesterol and oxysterols metabolism in the pharmacology of tamoxifen and other AEBS ligands

Tamoxifen is one of the major drugs used for the hormonotherapy of estrogen receptor positive breast cancers. However, its therapeutic efficacy can be limited by acquired resistance and tumor recurrence can occur after several years of treatment. Tamoxifen is known as the prototypical modulator of estrogen receptors, but other targets have been identified that could account for its pharmacology. In particular, tamoxifen binds with high affinity to the microsomal antiestrogen binding site (AEBS) and inhibits cholesterol esterification at therapeutic doses. We have recently shown that the AEBS was a hetero-oligomeric complex composed of 3β-hydroxysterol-Δ(8)-Δ(7)-isomerase and 3β-hydroxysterol-Δ(7)-reductase, that binds different structural classes of ligands, including selective estrogen receptor modulators, several sigma receptor ligands, poly-unsaturated fatty acids and ring B oxysterols. We established a link between the modulation of cholesterol metabolism by tamoxifen and other AEBS ligands and their capacity to induce breast cancer cell differentiation, apoptosis and autophagy. Moreover, we showed that the AEBS carries out cholesterol-5,6-epoxide hydrolase activity and established that cholesterol-5,6-epoxide hydrolase is a new target for tamoxifen and other AEBS ligands. Finally in this review, we report on recent data from the literature showing how the modulation of cholesterol and oxysterol metabolism can be linked to the antitumor and chemopreventive properties of tamoxifen, and give new perspectives to improve the clinical outcome of the hormonotherapy of breast cancers.

Mutational Profile of Metastatic Breast Cancers: A Retrospective Analysis.

Background Major advances have been achieved in the characterization of early breast cancer (eBC) genomic profiles. Metastatic breast cancer (mBC) is associated with poor outcomes, yet limited information is available on the genomic profile of this disease. This study aims to decipher mutational profiles of mBC using next-generation sequencing. Methods and Findings Whole-exome sequencing was performed on 216 tumor–blood pairs from mBC patients who underwent a biopsy in the context of the SAFIR01, SAFIR02, SHIVA, or Molecular Screening for Cancer Treatment Optimization (MOSCATO) prospective trials. Mutational profiles from 772 primary breast tumors from The Cancer Genome Atlas (TCGA) were used as a reference for comparing primary and mBC mutational profiles. Twelve genes (TP53, PIK3CA, GATA3, ESR1, MAP3K1, CDH1, AKT1, MAP2K4, RB1, PTEN, CBFB, and CDKN2A) were identified as significantly mutated in mBC (false discovery rate [FDR] < 0.1). Eight genes (ESR1, FSIP2, FRAS1, OSBPL3, EDC4, PALB2, IGFN1, and AGRN) were more frequently mutated in mBC as compared to eBC (FDR < 0.01). ESR1 was identified both as a driver and as a metastatic gene (n = 22, odds ratio = 29, 95% CI [9–155], p = 1.2e-12) and also presented with focal amplification (n = 9) for a total of 31 mBCs with either ESR1 mutation or amplification, including 27 hormone receptor positive (HR+) and HER2 negative (HER2−) mBCs (19%). HR+/HER2− mBC presented a high prevalence of mutations on genes located on the mechanistic target of rapamycin (mTOR) pathway (TSC1 and TSC2) as compared to HR+/HER2− eBC (respectively 6% and 0.7%, p = 0.0004). Other actionable genes were more frequently mutated in HR+ mBC, including ERBB4 (n = 8), NOTCH3 (n = 7), and ALK (n = 7). Analysis of mutational signatures revealed a significant increase in APOBEC-mediated mutagenesis in HR+/HER2− metastatic tumors as compared to primary TCGA samples (p < 2e-16). The main limitations of this study include the absence of bone metastases and the size of the cohort, which might not have allowed the identification of rare mutations and their effect on survival. Conclusions This work reports the results of the analysis of the first large-scale study on mutation profiles of mBC. This study revealed genomic alterations and mutational signatures involved in the resistance to therapies, including actionable mutations.

5,6-Epoxy-cholesterols contribute to the anticancer pharmacology of tamoxifen in breast cancer cells.

Tamoxifen (Tam) is a selective estrogen receptor modulator (SERM) that remains one of the major drugs used in the hormonotherapy of breast cancer (BC). In addition to its SERM activity, we recently showed that the oxidative metabolism of cholesterol plays a role in its anticancer pharmacology. We established that these effects were not regulated by the ER but by the microsomal antiestrogen binding site/cholesterol-5,6-epoxide hydrolase complex (AEBS/ChEH). The present study aimed to identify the oxysterols that are produced under Tam treatment and to define their mechanisms of action. Tam and PBPE (a selective AEBS/ChEH ligand) stimulated the production and the accumulation of 5,6α-epoxy-cholesterol (5,6α-EC), 5,6α-epoxy-cholesterol-3β-sulfate (5,6-ECS), 5,6β-epoxy-cholesterol (5,6β-EC) in MCF-7 cells through a ROS-dependent mechanism, by inhibiting ChEH and inducing sulfation of 5,6α-EC by SULT2B1b. We showed that only 5,6α-EC was responsible for the induction of triacylglycerol (TAG) biosynthesis by Tam and PBPE, through the modulation of the oxysterol receptor LXRβ. The cytotoxicity mediated by Tam and PBPE was triggered by 5,6β-EC through an LXRβ-independent route and by 5,6-ECS through an LXRβ-dependent mechanism. The importance of SULT2B1b was confirmed by its ectopic expression in the SULT2B1b(-) MDA-MB-231 cells, which became sensitive to 5,6α-EC, Tam or PBPE at a comparable level to MCF-7 cells. This study established that 5,6-EC metabolites contribute to the anticancer pharmacology of Tam and highlights a novel signaling pathway that points to a rationale for re-sensitizing BC cells to Tam and AEBS/ChEH ligands.

Cystatin C as a New Covariate to Predict Renal Elimination of Drugs Application to Carboplatin

Background and objectiveThe individual dosing of drugs that are mainly eliminated unchanged in the urine is made possible by assessing renal function. Most of the methods used are based on serum creatinine (SCr) levels. Cystatin C(CysC) has been proposed as an alternative endogenous marker of the glomerular filtration rate (GFR). Carboplatin is one of the drugs for which elimination is most dependent on the GFR. A prospective clinical trial including 45 patients was conducted to assess the value of serum CysC as a predictor of carboplatin clearance (CL).MethodsThe patients were receiving carboplatin as part of established protocols. Carboplatin was administered as a daily 60-minute infusion at doses ranging from 290 to 1700mg. A population pharmacokinetic analysis was performed using the nonlinear mixed effect modelling NONMEM program according to a two-compartment pharmacokinetic model.ResultsData from 30 patients were used to test the relationships between carboplatin CL and morphological, biological and demographic covariates previously proposed for prediction of the GFR. The interindividual variability of carboplatin CL decreased from 31% (no covariate) to 14% by taking into account five covariates (SCr, CysC, bodyweight [BW], age and sex). Prospective evaluation of these relationships using the data from the other 15 patients confirmed that the best equation to predict carboplatin CL was based on these five covariates, with a mean absolute percentage error of 13% as an assessment of precision. NONMEM analysis of the whole dataset (n = 45 patients) was performed. The best covariate equation corresponding to the overall analysis was: CL (mL/min) = 110 · (SCr/75)−0.512 · (CysC/1.0)−0.327 · (BW/65)0.474 · (age/ 56)−0.387 · 0.854sex, with SCr in μmol/L, CysC in mg/L, BW in kilograms, age in years and sex = 0 if male and 1 if female. To put the value of CysC as an endogenous marker of the GFR into perspective, covariate equations without SCr were also evaluated; a better prediction was obtained by considering CysC together with age and BW (interindividual variability of 16.6% vs 23.3% for CysC alone).ConclusionCysC is a marker of drug elimination that is at least as good as SCr for predicting carboplatin CL. The model based on five covariates was superior to those based on only four covariates (with BW, age and sex combined with either SCr or CysC), indicating that CysC and SCr are not completely redundant to each other. Further pharmacokinetic evaluation is needed to determine whether SCr or CysC is the better marker of renal elimination of other drugs.