Julie Means-Powell

Identification of markers of taxane sensitivity using proteomic and genomic analyses of breast tumors from patients receiving neoadjuvant paclitaxel and radiation.

Purpose: To identify molecular markers of pathologic response to neoadjuvant paclitaxel/radiation treatment, protein and gene expression profiling were done on pretreatment biopsies. Experimental Design: Patients with high-risk, operable breast cancer were treated with three cycles of paclitaxel followed by concurrent paclitaxel/radiation. Tumor tissue from pretreatment biopsies was obtained from 19 of the 38 patients enrolled in the study. Protein and gene expression profiling were done on serial sections of the biopsies from patients that achieved a pathologic complete response (pCR) and compared to those with residual disease, non-pCR (NR). Results: Proteomic and validation immunohistochemical analyses revealed that α-defensins (DEFA) were overexpressed in tumors from patients with a pCR. Gene expression analysis revealed that MAP2, a microtubule-associated protein, had significantly higher levels of expression in patients achieving a pCR. Elevation of MAP2 in breast cancer cell lines led to increased paclitaxel sensitivity. Furthermore, expression of genes that are associated with the basal-like, triple-negative phenotype were enriched in tumors from patients with a pCR. Analysis of a larger panel of tumors from patients receiving presurgical taxane-based treatment showed that DEFA and MAP2 expression as well as histologic features of inflammation were all statistically associated with response to therapy at the time of surgery. Conclusion: We show the utility of molecular profiling of pretreatment biopsies to discover markers of response. Our results suggest the potential use of immune signaling molecules such as DEFA as well as MAP2, a microtubule-associated protein, as tumor markers that associate with response to neoadjuvant taxane–based therapy. Clin Cancer Res; 16(2); 681–90

DCE-MRI analysis methods for predicting the response of breast cancer to neoadjuvant chemotherapy: Pilot study findings

The purpose of this pilot study is to determine (1) if early changes in both semiquantitative and quantitative DCE‐MRI parameters, observed after the first cycle of neoadjuvant chemotherapy in breast cancer patients, show significant difference between responders and nonresponders and (2) if these parameters can be used as a prognostic indicator of the eventual response.

Multiparametric magnetic resonance imaging for predicting pathological response after the first cycle of neoadjuvant chemotherapy in breast cancer.

ObjectivesThe purpose of this study was to determine whether multiparametric magnetic resonance imaging (MRI) using dynamic contrast-enhanced MRI (DCE-MRI) and diffusion-weighted MRI (DWI), obtained before and after the first cycle of neoadjuvant chemotherapy (NAC), is superior to single-parameter measurements for predicting pathologic complete response (pCR) in patients with breast cancer. Materials and MethodsPatients with stage II/III breast cancer were enrolled in an institutional review board–approved study in which 3-T DCE-MRI and DWI data were acquired before (n = 42) and after 1 cycle (n = 36) of NAC. Estimates of the volume transfer rate (Ktrans), extravascular extracellular volume fraction (ve), blood plasma volume fraction (vp), and the efflux rate constant (kep = Ktrans/ve) were generated from the DCE-MRI data using the Extended Tofts-Kety model. The apparent diffusion coefficient (ADC) was estimated from the DWI data. The derived parameter kep/ADC was compared with single-parameter measurements for its ability to predict pCR after the first cycle of NAC. ResultsThe kep/ADC after the first cycle of NAC discriminated patients who went on to achieve a pCR (P < 0.001) and achieved a sensitivity, specificity, positive predictive value, and area under the receiver operator curve (AUC) of 0.92, 0.78, 0.69, and 0.88, respectively. These values were superior to the single parameters kep (AUC, 0.76) and ADC (AUC, 0.82). The AUCs between kep/ADC and kep were significantly different on the basis of the bootstrapped 95% confidence intervals (0.018–0.23), whereas the AUCs between kep/ADC and ADC trended toward significance (−0.11 to 0.24). ConclusionsThe multiparametric analysis of DCE-MRI and DWI was superior to the single-parameter measurements for predicting pCR after the first cycle of NAC.

A novel AIF tracking method and comparison of DCE-MRI parameters using individual and population-based AIFs in human breast cancer.

Quantitative analysis of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) data requires the accurate determination of the arterial input function (AIF). A novel method for obtaining the AIF is presented here and pharmacokinetic parameters derived from individual and population-based AIFs are then compared. A Philips 3.0 T Achieva MR scanner was used to obtain 20 DCE-MRI data sets from ten breast cancer patients prior to and after one cycle of chemotherapy. Using a semi-automated method to estimate the AIF from the axillary artery, we obtain the AIF for each patient, AIF(ind), and compute a population-averaged AIF, AIF(pop). The extended standard model is used to estimate the physiological parameters using the two types of AIFs. The mean concordance correlation coefficient (CCC) for the AIFs segmented manually and by the proposed AIF tracking approach is 0.96, indicating accurate and automatic tracking of an AIF in DCE-MRI data of the breast is possible. Regarding the kinetic parameters, the CCC values for K(trans), v(p) and v(e) as estimated by AIF(ind) and AIF(pop) are 0.65, 0.74 and 0.31, respectively, based on the region of interest analysis. The average CCC values for the voxel-by-voxel analysis are 0.76, 0.84 and 0.68 for K(trans), v(p) and v(e), respectively. This work indicates that K(trans) and v(p) show good agreement between AIF(pop) and AIF(ind) while there is a weak agreement on v(e).

Statistical comparison of dynamic contrast-enhanced MRI pharmacokinetic models in human breast cancer.

By fitting dynamic contrast‐enhanced MRI data to an appropriate pharmacokinetic model, quantitative physiological parameters can be estimated. In this study, we compare four different models by applying four statistical measures to assess their ability to describe dynamic contrast‐enhanced MRI data obtained in 28 human breast cancer patient sets: the chi‐square test (χ2), Durbin–Watson statistic, Akaike information criterion, and Bayesian information criterion. The pharmacokinetic models include the fast exchange limit model with (FXL_vp) and without (FXL) a plasma component, and the fast and slow exchange regime models (FXR and SXR, respectively). The results show that the FXL_vp and FXR models yielded the smallest χ2 in 45.64 and 47.53% of the voxels, respectively; they also had the smallest number of voxels showing serial correlation with 0.71 and 2.33%, respectively. The Akaike information criterion indicated that the FXL_vp and FXR models were preferred in 42.84 and 46.59% of the voxels, respectively. The Bayesian information criterion also indicated the FXL_vp and FXR models were preferred in 39.39 and 45.25% of the voxels, respectively. Thus, these four metrics indicate that the FXL_vp and the FXR models provide the most complete statistical description of dynamic contrast‐enhanced MRI time courses for the patients selected in this study. Magn Reson Med, 2012.

Temporal sampling requirements for reference region modeling of DCE-MRI data in human breast cancer

To assess the temporal sampling requirements needed for quantitative analysis of dynamic contrast‐enhanced MRI (DCE‐MRI) data with a reference region (RR) model in human breast cancer.

Motion correction in diffusion-weighted MRI of the breast at 3T

To provide a quantitative assessment of motion and distortion correction of diffusion‐weighted images (DWIs) of the breast and to evaluate the effects of registration on the mean apparent diffusion coefficient (mADC).

A Phase Ib Trial of RAD001, an mTOR Inhibitor, with Weekly Cisplatin and Paclitaxel in Patients with HER2-Negative Metastatic Breast Cancer.

Background: Pre-clinical data suggests that in basal-like breast cancers (triple-negative and some luminal B), drugs that either negatively modulate p63 and/or activate p73, such as cisplatin and paclitaxel, promote p73-dependent apoptosis. This is enhanced upon concomitant inhibition of mTOR with RAD001 (Everolimus). We conducted a phase Ib trial in patients with HER2-negative metastatic breast cancer to explore the safety, tolerability and anti-tumor activity of the combination of paclitaxel, cisplatin and RAD001.Materials and Methods: This was an open-label, phase Ib dose-escalation study. RAD001 was started at 20 mg/week on a 28-day treatment cycle, and was escalated over 3 dose levels (20, 25 and 30 mg/week). Cisplatin (25 mg/m2) and paclitaxel (80 mg/m2) doses were fixed, and were administered once a week for 3 weeks on a 28-day treatment cycle. Treatment was continued until dose-limiting toxicity (DLT) was observed or until progression of disease. All toxicities were documented using the NCI CTC v.3. Disease assessment was done every 2 months after initiation of therapy.Results: A total of 16 patients were enrolled. Median age was 55 years and the median number of previous chemotherapy regimens in the metastatic setting was 3. Seventy percent of the patients had triple-negative disease, all patients had metastatic visceral disease, and 25% of those had concomitant bone metastasis. Three patients are still on study, but have not had their first assessment of disease. Of the 13 patients that are currently evaluable for best response, 1 had a complete response (CR), 2 had partial response (PR), 7 had stable disease (SD), and 3 had disease progression (PD) at their first disease assessment. All patients with CR or PR received the higher dose level (RAD001 30 mg/week). Twelve patients have discontinued study drugs at this time; 7 due to disease progression, 3 due to toxicity and 2 due to maximum benefit. Overall median time to progression (TTP) was 5 months. The most common toxicities were alopecia (100%), neutropenia (28%), anemia (10%) and fatigue (5%). Grade 3 and 4 toxicities were overall uncommon (8.5%) and consisted of neutropenia which lasted for less than 5 days. No DLTs were seen at any of the dose levels.Discussion: The combination of weekly RAD001, cisplatin and paclitaxel was overall very well tolerated, despite neutropenia (non-dose limiting and without serious sequelae). Significant antitumor activity in this heavily pre-treated patient population was seen at all dose levels and appeared to be higher in the group treated with RAD001 30 mg/week. The recommended phase II doses for this combination are cisplatin 25 mg/m2, paclitaxel 80 mg/m2 given weekly for 3 weeks, and RAD 30 mg/week, on a 28-day treatment cycle. A phase Ib-II study of cisplatin, paclitaxel, and daily doses of RAD001 is ongoing. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3093.

Sympathetic nervous system alterations with HER2+ antagonism: an early marker of cardiac dysfunction with breast cancer treatment?

Background HER2 antagonists (anti-HER2; e.g., trastuzumab and lapatinib) are effective in treating an aggressive form of breast cancer (BC), but can cause cardiotoxicity due to the disruption in neuregulin (NRG)/HER2+ ligand receptor signalling. The recent data show that NRG-HER2 receptors located in the medulla oblongata are important regulators of vasomotor tone. Disrupting the NRG-HER2 signalling in mouse medulla results in increased sympathetic nerve output and blood pressure. We hypothesized that anti-HER2 agents would cause increased sympathetic tone with changes in plasma catecholamines and NRG. Methods In 15 newly diagnosed HER2+ BC patients receiving anti-HER2 agents, vital signs were measured along with supine plasma epinephrine (EPI), norepinephrine (NE), and NRG at baseline and three months. Serial echocardiography was performed. Results With three months of anti-HER2 treatment, NE increased (2.334 ± 1.294 nmol/L vs. 3.262 ± 2.103 nmol/L; p = 0.004) and NRG decreased (12.7±15.7 ng/ml vs. 10.9 ± 13.3 ng/ml; p = 0.036) with a corresponding increase in systolic blood pressure (110 ± 10 mmHg vs. 120 ± 16 mmHg, p = 0.049) and diastolic blood pressure (67 ± 14 vs. 77 ± 10, p = 0.009). There was no change, however, in EPI (0.183 ± 0.151 nmol/L vs. 0.159 ± 0.174 nmol/L; p = 0.519) or heart rate (73 ± 12 bpm vs. 77 ± 10 bpm, p = 0.146). Left ventricular ejection function declined over the follow-up period (baseline 63 ± 6% vs. follow-up 56 ± 5%). Conclusions Anti-HER2 treatment results in increased NE, blood pressure, and decreased NRG; this suggests that the inhibition of NRGHER2 signalling leads to increased sympathoneural tone. Larger studies are needed to determine if these observations have prognostic value and may be offset with medical interventions, such as beta-blockers. Clinical Trial Registration The study was registered with www.clinicaltrials.gov (NCT00875238).

PD09-06: Phase II Trial of RAD001 (Everolimus), an mTOR Inhibitor, with Weekly Cisplatin and Paclitaxel in Patients with HER2−Negative Metastatic Breast Cancer (MBC).

Background: In basal-like breast cancers, drugs that either negatively modulate p63 and/or activate p73, such as cisplatin and paclitaxel, promote p73-dependent apoptosis. Further, the serine threonine kinase mTOR negatively regulates p73. Inhibition of mTOR with RAD001 upregulates p73, and results in p73-mediated apoptosis. Therefore, we conducted a phase II trial in patients with HER2−negative MBC to explore safety, tolerability and anti-tumor activity of the combination of paclitaxel, cisplatin and RAD001. Materials and Methods: We initiated an open-label, phase II multi-institutional study of weekly cisplatin (25 mg/m2), paclitaxel (80 mg/m2) and daily RAD001 (5 mg), given on a 28-day cycle. Treatment was continued until unacceptable toxicity or progression of disease. All toxicities were documented using the NCICTCv.4. Disease was assessed every 2 months. Results: A total of 55 patients were enrolled. Median age was 55 years; 62% of patients had prior chemotherapy with a median of 3 previous regimens in the metastatic setting. Sixty-three percent of patients had triple-negative disease, 81% patients had visceral disease, and 35% had bone metastases. Twenty-one patients are still on study. The most common toxicities are summarized in the table below. Neutropenia was the main cause for dose reductions, mainly after cycle 3. Only 1 patient developed febrile neutropenia. Of the 44 patients assessed for best response (RECIST) thus far, 11 had partial response, 21 stable disease, 9 disease progression, and 3 were not evaluable. Thirty eight patients have discontinued treatment so far; 30 due to disease progression, 5 due to toxicity, and 3 withdrew consent. Current median time to progression on the evaluable patients is 6 months. Discussion: The combination of RAD001, cisplatin and paclitaxel was overall very well tolerated despite cumulative pancytopenia. Significant antitumor activity in this heavily pre-treated patient population was seen. All patients’ primary diagnostic and/or metastatic tumor biopsies are currently being analyzed for the presence of PIK3CA and AKT1 mutations, and immunohistochemical expression of p53, p63, p73, and PTEN. Microarrays are being generated to determine whether time to progression is superior in patients with basal-like breast cancers. Microarrays will be mined to identify a pretreatment profile that mirrors a low p63/high p73 gene expression signature. Correlation of mutational analysis and gene signatures with clinical benefit will be presented at the meeting Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr PD09-06.