Response to Neoadjuvant Therapy and Long-Term Survival in Patients With Triple-Negative Breast Cancer.

PURPOSE: Triple-negative breast cancer (TNBC) is defined by the lack of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER-2) expression. In this study, we compared response to neoadjuvant chemotherapy and survival between patients with TNBC and non-TNBC. PATIENTS AND METHODS: Analysis of a prospectively collected clinical database was performed. We included 1,118 patients who received neoadjuvant chemotherapy at M.D. Anderson Cancer Center for stage I-III breast cancer from 1985 to 2004 and for whom complete receptor information were available. Clinical and pathologic parameters, pathologic complete response rates (pCR), survival measurements, and organ-specific relapse rates were compared between patients with TNBC and non-TNBC. RESULTS: Two hundred fifty-five patients (23%) had TNBC. Patients with TNBC compared with non-TNBC had significantly higher pCR rates (22% v 11%; P = .034), but decreased 3-year progression-free survival rates (P < .0001) and 3-year overall survival (OS) rates (P < .0001). TNBC was associated with increased risk for visceral metastases (P = .0005), lower risk for bone recurrence (P = .027), and shorter postrecurrence survival (P < .0001). Recurrence and death rates were higher for TNBC only in the first 3 years. If pCR was achieved, patients with TNBC and non-TNBC had similar survival (P = .24). In contrast, patients with residual disease (RD) had worse OS if they had TNBC compared with non-TNBC (P < .0001). CONCLUSION: Patients with TNBC have increased pCR rates compared with non-TNBC, and those with pCR have excellent survival. However, patients with RD after neoadjuvant chemotherapy have significantly worse survival if they have TNBC compared with non-TNBC, particularly in the first 3 years.

Dynamic clonal remodelling in breast cancer metastases is associated with subtype conversion.

BACKGROUND: Changes in the clinical subtype (CS) and intrinsic subtype (IS) between breast cancer (BC) metastases and corresponding primary tumours have been reported. However, their relationship with tumour genomic changes remains poorly characterised. Here, we analysed the association between genomic remodelling and subtype conversion in paired primary and metastatic BC samples. METHODS: A total of 57 paired primary and metastatic tumours from GEICAM/2009-03 (ConvertHER, NCT01377363) study participants with centrally assessed CS (n = 57) and IS (n = 46) were analysed. Targeted capture and next-generation sequencing of 202 genes on formalin-fixed paraffin-embedded samples was performed. The cancer cell fraction (CCF) of mutations in primary and metastatic pairs was estimated as a surrogate of tumour clonal architecture. Changes in mutation CCF between matched primary and metastatic tumours were analysed in the presence or absence of subtype conversion. FINDINGS: CS conversion occurred in 24.6% and IS conversion occurred in 36.9% of metastases. Primary tumours and metastases had a median of 11 (range, 3-29) and 9 (range, 1-38) mutations, respectively (P = 0.05). Overall, mutations in metastases showed a higher estimated CCF than in primary tumours (median CCF, 0.51 and 0.47, respectively; P = 0.042), consistent with increased clonal homogeneity. The increase in mutation CCF was significant in CS-converted (P = 0.04) but not in IS-converted (P = 0.48) metastases. Clonal remodelling was highest in metastases from hormone receptor-positive and human epidermal growth factor 2 (HER2)-positive tumours (P = 0.006). CONCLUSIONS: Mutations in BC metastases showed significantly higher estimated CCF than primary tumours. CCF changes were more prominent in metastases with CS conversion. Our findings suggest that changes in BC subtypes are linked to clonal remodelling during BC evolution.

Cooperative Effect of Oncogenic MET and PIK3CA in an HGF-Dominant Environment in Breast Cancer.

There is compelling evidence that oncogenic MET and PIK3CA signaling pathways contribute to breast cancer. However, the activity of pharmacologic targeting of either pathway is modest. Mechanisms of resistance to these monotherapies have not been clarified. Currently, commonly used mouse models are inadequate for studying the HGF-MET axis because mouse HGF does not bind human MET. We established human HGF-MET paired mouse models. In this study, we evaluated the cooperative effects of MET and PIK3CA in an environment with involvement of human HGF in vivo Oncogenic MET/PIK3CA synergistically induced aggressive behavior and resistance to each targeted therapy in an HGF-paracrine environment. Combined targeting of MET and PI3K abrogates resistance. Associated cell signaling changes were explored by functional proteomics. Consistently, combined targeting of MET and PI3K inhibited activation of associated oncogenic pathways. We also evaluated the response of tumor cells to HGF stimulation using breast cancer patient-derived xenografts (PDX). HGF stimulation induced significant phosphorylation of MET for all PDX lines detected to varying degrees. However, the levels of phosphorylated MET are not correlated with its expression, suggesting that MET expression level cannot be used as a sole criterion to recruit patients to clinical trials for MET-targeted therapy. Altogether, our data suggest that combined targeting of MET and PI3K could be a potential clinical strategy for breast cancer patients, where phosphorylated MET and PIK3CA mutation status would be biomarkers for selecting patients who are most likely to derive benefit from these cotargeted therapy.

Impact of clinical trial on survival outcomes.

The number of patients with breast cancer who participate in therapeutic clinical trials remains low. One reason is a lack of opportunity; another is health care providers who do not recommend trials because they fear poorer outcome from the use of new drugs. Thus, we compared survival outcome in patients with metastatic breast cancer (MBC) who participated in first-line therapeutic clinical trials with outcome in patients who had never enrolled in a clinical trial and received only standard care. We hypothesized that first-line therapeutic clinical trials does not have a negative survival outcome. We reviewed the records of patients with MBC who were treated at MD Anderson Cancer Center between January 2000, and December 2010. The medical records of 5501 patients with MBC were screened, and 652 patients-285 in the trial arm and 367 in the control arm-met our specific eligible criteria. The median follow-up of our cohort was 7.16 years (95 % confidence interval [CI] 6.53-7.64 years). Among the global population, no significant differences in progression-free survival (PFS) or overall survival (OS) were observed between the treatment arms: for the clinical trial cohort, median PFS was 7 months (95 % CI 5.72-8.71 months), and median OS was 28.48 months (95 % CI 22.70-34.60 months). For the control cohort, median PFS was 10.02 months (95 % CI 7.13-11.99 months), and median OS was 28.71 months (95 % CI 24.41-31.31 months) (P = .089 and .335, respectively). Enrollment in first-line MBC therapeutic clinical trials does not result in less favorable survival outcome than that in MBC patients who never enrolled in a clinical trial.

Use of Biomarkers to Guide Decisions on Adjuvant Systemic Therapy for Women With Early-Stage Invasive Breast Cancer: American Society of Clinical Oncology Clinical Practice Guideline.

PURPOSE: To provide recommendations on appropriate use of breast tumor biomarker assay results to guide decisions on adjuvant systemic therapy for women with early-stage invasive breast cancer. METHODS: A literature search and prospectively defined study selection sought systematic reviews, meta-analyses, randomized controlled trials, prospective-retrospective studies, and prospective comparative observational studies published from 2006 through 2014. Outcomes of interest included overall survival and disease-free or recurrence-free survival. Expert panel members used informal consensus to develop evidence-based guideline recommendations. RESULTS: The literature search identified 50 relevant studies. One randomized clinical trial and 18 prospective-retrospective studies were found to have evaluated the clinical utility, as defined by the guideline, of specific biomarkers for guiding decisions on the need for adjuvant systemic therapy. No studies that met guideline criteria for clinical utility were found to guide choice of specific treatments or regimens. RECOMMENDATIONS: In addition to estrogen and progesterone receptors and human epidermal growth factor receptor 2, the panel found sufficient evidence of clinical utility for the biomarker assays Oncotype DX, EndoPredict, PAM50, Breast Cancer Index, and urokinase plasminogen activator and plasminogen activator inhibitor type 1 in specific subgroups of breast cancer. No biomarker except for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 was found to guide choices of specific treatment regimens. Treatment decisions should also consider disease stage, comorbidities, and patient preferences.

Antiepileptic drug use improves overall survival in breast cancer patients with brain metastases in the setting of whole brain radiotherapy.

BACKGROUND AND PURPOSE: There is mounting evidence that histone deacetylase (HDAC) inhibitors, e.g. valproic acid (VPA), synergize with radiation to improve outcomes in several cancers. This study was conducted to ascertain whether VPA affected outcomes in breast cancer patients with brain metastases treated with whole brain radiotherapy (WBRT). MATERIALS AND METHODS: Records from 253 breast cancer patients with brain metastases treated with WBRT were reviewed. Data regarding use of all antiepileptic drugs (AEDs) were extracted. Kaplan-Meier survival times were calculated using the date of brain involvement as time zero. Cox proportional hazard models were used to determine the association between patient and tumor characteristics and overall survival (OS). RESULTS: Median OS for the entire patient cohort was 6 months. Patients receiving VPA (n=20) had a median OS of 11 months versus 5 months for those not receiving VPA (p=0.028). Median OS was 9 months for patients taking any AED (n=101) versus 4 months for those not taking AEDs (p=0.0003). On multivariate analysis both VPA and AED use were associated with improved OS (HR 0.61, p=0.0419; HR 0.59, p=0.0002, respectively). CONCLUSIONS: This study suggests the use of AEDs, including VPA, is associated with improved OS in breast cancer patients with brain metastases following WBRT.

Multigene clinical mutational profiling of breast carcinoma using next-generation sequencing.

OBJECTIVES: The advent of next-generation sequencing (NGS) platforms in the realm of clinical molecular diagnostics provides multigene mutational profiling through massively parallel sequencing. METHODS: We analyzed 415 breast carcinoma samples from 354 patients using NGS in known hotspots of 46 commonly known cancer-causing genes. RESULTS: A total of 281 somatic nonsynonymous mutations were detected in 62.1% of patients. TP53 was most frequently mutated (38.8%), followed by PIK3CA (31.7%), AKT1 (6%), and ATM (3.9%), with other mutations detected at a lower frequency. When stratified into clinically relevant therapeutic groups (estrogen receptor [ER]/progesterone receptor [PR]+ human epidermal growth factor receptor 2 [HER2]-, ER/PR+HER2+, ER/PR-HER2+, ER/PR/HER2-), each group showed distinct mutational profiles. The ER/PR+HER2- tumors (n = 132) showed the highest frequency of PIK3CA mutations (38%), while the triple-negative tumors (n = 64) had a significantly higher number of TP53 mutations (62%). Of the 61 patients tested for both primary and metastatic tumors, concordant results were seen in 47 (77%) patients, while 13 patients showed additional mutations in the metastasis. CONCLUSIONS: Our results indicate that breast cancers may harbor potentially actionable mutations for targeted therapeutics. Therefore, NGS-based mutational profiling can provide useful information that can guide targeted cancer therapy.

Recurrence and survival among breast cancer patients achieving a pathological complete response to neoadjuvant chemotherapy.

Patients who achieve a pathological complete response (pCR) after neoadjuvant therapy, including chemotherapy with or without trastuzumab (NAT) have better outcomes than patients with residual disease. Despite the excellent prognosis associated with achieving a pCR, tumors still recur. The objective of this study was to evaluate factors associated with tumor recurrence and survival among patients achieving pCR after NAT. We identified 749 patients with primary breast cancer who achieved pCR after NAT between 1988 and 2009. pCR was defined as no evidence of invasive cancer in the breast and ipsilateral axillary lymph nodes on pathological evaluation. The Kaplan-Meier product limit method and multivariate Cox proportional hazards models were used to determine the association between clinical and demographic factors and outcomes. Median follow-up was 35 months (range, 1-258 months). Overall 5-year distant metastasis-free survival was 93% (95% confidence interval [CI], 90-95%) and 5-year overall survival (OS) was 96% (95% CI, 93-97%). In the multivariable model, we observed that patients >50 years had significantly decreased risk of distant metastasis (hazard ratio [HR] 0.47; 95% CI, 0.22-0.98) and that patients with clinical stage at diagnosis IIIB-C cancer had both an increased risk of distant metastasis (HR 3.92; 95% CI, 1.54-10.00) and lower OS (HR 4.75; 95% CI, 1.60-14.08). Patients with pCR after NAT have excellent outcomes. However, our data show that younger patient and those with clinical stage at diagnosis IIIB and IIIC cancers are at increased risk of developing distant metastasis.

Effect of 21-Gene RT-PCR Assay on Adjuvant Therapy and Outcomes in Patients With Stage I Breast Cancer.

BACKGROUND: Recurrence score (RS) derived from a 21-gene reverse transcriptase-polymerase chain reaction assay is used to stratify patients with early-stage estrogen receptor-positive, HER2-normal breast cancer into 3 groups on the basis of 10-year distant metastasis risk: low, intermediate, and high. Published data are limited regarding the effect of RS on choice of adjuvant therapy for T1 breast cancer. We investigated the relationship between RS and choice of adjuvant therapy, prognosis, and benefit of chemotherapy (CT) in stage I breast cancer. MATERIALS AND METHODS: We reviewed the records of 1030 patients with estrogen receptor-positive, HER2-normal stage I breast cancer and RS available. RSs were correlated with clinicopathologic characteristics, treatment, and outcome. RESULTS: Patients with pathologic (p)T1a, pT1b, and pT1c disease did not differ in distribution of low, intermediate, and high RS (P = .673). Overall, fewer than 10% of patients had a high RS. Histologic grade 1, nuclear grade 1, and low Ki-67 expression had only 1%, 0%, and 6% of high RSs, respectively. Among patients with intermediate RSs, 41% with pT1b and 46% with pT1c disease received CT. Among patients with intermediate RSs, for pT1b disease, distant disease-free survival (DDFS) did not differ between hormonal therapy (HT) alone and CT with HT (P = .752); for pT1c, DDFS was superior for CT with HT (P = .020). Histologic grade was the only independent prognostic factor of DDFS (P = .0007, 1 vs. 3; P = .035, 2 vs. 3); RS did not predict DDFS (P = .083, high vs. low; P = .066, intermediate vs. low). CONCLUSION: The added value of RS to known prognostic factors appears limited to patients with pT1b breast cancer. However, this study lacked long-term follow-up.

Use of Biomarkers to Guide Decisions on Systemic Therapy for Women With Metastatic Breast Cancer: American Society of Clinical Oncology Clinical Practice Guideline.

PURPOSE: To provide recommendations on the appropriate use of breast tumor biomarker assay results to guide decisions on systemic therapy for metastatic breast cancer. METHODS: A literature search and prospectively defined study selection identified systematic reviews, meta-analyses, randomized controlled trials (RCTs), prospective-retrospective studies, and prospective comparative observational studies published from 2006 through September 2014. RESULTS: The literature search revealed 17 articles that met criteria for further review: 11 studies reporting discordances between primary tumors and metastases in expression of hormone receptors or human epidermal growth factor receptor 2 (HER2), one RCT that addressed the use of a biomarker to decide whether to change or continue a treatment regimen, and five prospective-retrospective studies that evaluated the clinical utility of biomarkers. RECOMMENDATIONS: In patients with accessible metastases, biopsy for confirmation of disease process and retesting of estrogen receptor, progesterone receptor, and HER2 status should be offered, but evidence is lacking to determine whether changing anticancer treatment on the basis of change in receptor status affects clinical outcomes. With discordance of results between primary and metastatic tissues, the Panel consensus is to use preferentially the estrogen receptor, progesterone receptor, and HER2 status of the metastasis to direct therapy if supported by the clinical scenario and patient's goals for care. Carcinoembryonic antigen, cancer antigen 15-3, and cancer antigen 27-29 may be used as adjunctive assessments, but not alone, to contribute to decisions regarding therapy. Recommendations for tumor rebiopsy and use of circulating tumor markers are based on clinical experience and Panel informal consensus in the absence of studies designed to evaluate the clinical utility of the markers. As such, it is also reasonable for clinicians to not use these markers as adjunctive assessments.

Validation and Development of a Modified Breast Graded Prognostic Assessment As a Tool for Survival in Patients With Breast Cancer and Brain Metastases.

PURPOSE: Several indices have been developed to predict overall survival (OS) in patients with breast cancer with brain metastases, including the breast graded prognostic assessment (breast-GPA), comprising age, tumor subtype, and Karnofsky performance score. However, number of brain metastases-a highly relevant clinical variable-is less often incorporated into the final model. We sought to validate the existing breast-GPA in an independent larger cohort and refine it integrating number of brain metastases. PATIENTS AND METHODS: Data were retrospectively gathered from a prospectively maintained institutional database. Patients with newly diagnosed brain metastases from 1996 to 2013 were identified. After validating the breast-GPA, multivariable Cox regression and recursive partitioning analysis led to the development of the modified breast-GPA. The performances of the breast-GPA and modified breast-GPA were compared using the concordance index. RESULTS: In our cohort of 1,552 patients, the breast-GPA was validated as a prognostic tool for OS (P < .001). In multivariable analysis of the breast-GPA and number of brain metastases (> three v ≤ three), both were independent predictors of OS. We therefore developed the modified breast-GPA integrating a fourth clinical parameter. Recursive partitioning analysis reinforced the prognostic significance of these four factors. Concordance indices were 0.78 (95% CI, 0.77 to 0.80) and 0.84 (95% CI, 0.83 to 0.85) for the breast-GPA and modified breast-GPA, respectively (P < .001). CONCLUSION: The modified breast-GPA incorporates four simple clinical parameters of high prognostic significance. This index has an immediate role in the clinic as a formative part of the clinician's discussion of prognosis and direction of care and as a potential patient selection tool for clinical trials.

Is the future of personalized therapy in triple-negative breast cancer based on molecular subtype?

Significant research has been conducted to better understand the extensive, heterogeneous molecular features of triple-negative breast cancer (TNBC). We reviewed published TNBC molecular classifications to identify major groupings that have potential for clinical trial development. With the ultimate aim to streamline translational medicine, we linked these categories of TNBC according to their gene-expression signatures, biological function, and clinical outcome. To this end, we define five potential clinically actionable groupings of TNBC: 1) basal-like TNBC with DNA-repair deficiency or growth factor pathways; 2) mesenchymal-like TNBC with epithelial-to-mesenchymal transition and cancer stem cell features; 3) immune-associated TNBC; 4) luminal/apocrine TNBC with androgen-receptor overexpression; and 5) HER2-enriched TNBC. For each defined subtype, we highlight the major biological pathways and discuss potential targeted therapies in TNBC that might abrogate disease progression. However, many of these potential targets need clinical validation by clinical trials. We have yet to know how we can enrich the targets by molecular classifications.

Phase II Randomized Study of Ixabepilone Versus Observation in Patients With Significant Residual Disease After Neoadjuvant Systemic Therapy for HER2-Negative Breast Cancer.

BACKGROUND: Residual disease (RD) after neoadjuvant chemotherapy carries an increased risk for recurrence. Ixabepilone has activity in anthracycline/taxanes-resistant breast cancer. We explored adjuvant ixabepilone in patients with significant RD HER2-negative breast cancer. METHODS: A phase II study in patients with residual cancer burden II or III randomized to ixabepilone versus observation was conducted. Circulating tumor cells (CTCs) were measured at baseline and at 9 and 18 weeks. Survival probabilities were estimated by Kaplan-Meier product limit. Toxicities were reported as proportions in the ixabepilone arm. RESULTS: Accrual was stopped because of ixabepilone toxicity. Sixty-seven patients were registered; 43 were randomized, 19 received ixabepilone, and 24 went to observation. One patient (9.1%) in the observation arm versus 2 patients (18.2%) in the ixabepilone arm had CTCs at 18 weeks (P = 1.0). Three-year recurrence-free survival and overall survival were 94% and 82%, and 100% and 79% in the observation and ixabepilone arms (P = .35 and .18), respectively. Most common adverse events (AEs) included fatigue, pain, neuropathy, constipation, nausea, rash, anorexia, and diarrhea. Serious AEs included pain (63.2%), fatigue (31.6%), and neuropathy (31.6%). CONCLUSIONS: Adjuvant ixabepilone in patients with significant RD after neoadjuvant chemotherapy was difficult to administer because of AEs and did not change the presence of CTC or affect survival outcomes. NCT00877500.

SU2C phase Ib study of paclitaxel and MK-2206 in advanced solid tumors and metastatic breast cancer.

BACKGROUND: There is preclinical synergism between taxanes and MK-2206. We aim to determine the maximum tolerated dose, safety, and activity of combining MK-2206 and paclitaxel in metastatic cancer. METHODS: Patients received weekly doses of paclitaxel at 80mg/m2 on day 1, followed by MK-2206 orally on day 2 escalated at 90mg, 135mg, and 200mg. Treatment continued until progression, excessive toxicity, or patient request. Blood and tissue were collected for pharmacokinetic and pharmacodynamics markers. A cycle consisted of three weeks of therapy. Dose-limiting toxicity (DLT) was defined as unacceptable toxicity during the first cycle. All statistical tests were two-sided. RESULTS: Twenty-two patients were treated, nine in dose escalation and 13 in dose expansion. Median age was 55 years. Median number of cycles was four. Dose escalation was completed with no DLT. CTCAE Grade 3 or higher adverse events were fatigue (n = 2), rash (n = 2), hyperglycemia (n = 1), and neutropenia (n = 7). Four patients in the expansion phase required MK-2206 dose reduction. Phase II recommended dose was established as paclitaxel 80mg/m2 weekly on day 1, and MK-2206 135mg weekly on day 2. Paclitaxel systemic exposure was similar in the presence or absence of MK-2206. Plasma MK-2206 concentrations were similar to data from previous phase I monotherapy. There was a statistically significant decrease in expression of pAKT S473 (P = .01) and pAKT T308 (P = .002) after therapy. PI3K/AKT/mTOR downregulation in tumor tissues and circulating markers did not correlate with tumor response or clinical benefit. There were five objective responses, and nine patients had stable disease. CONCLUSION: MK-2206 was well tolerated with paclitaxel. Preliminary antitumor activity was documented.

Functional consequence of the MET-T1010I polymorphism in breast cancer.

Major breast cancer predisposition genes, only account for approximately 30% of high-risk breast cancer families and only explain 15% of breast cancer familial relative risk. The HGF growth factor receptor MET is potentially functionally altered due to an uncommon germline single nucleotide polymorphism (SNP), MET-T1010I, in many cancer lineages including breast cancer where the MET-T1010I SNP is present in 2% of patients with metastatic breast cancer. Expression of MET-T1010I in the context of mammary epithelium increases colony formation, cell migration and invasion in-vitro and tumor growth and invasion in-vivo. A selective effect of MET-T1010I as compared to wild type MET on cell invasion both in-vitro and in-vivo suggests that the MET-T1010I SNP may alter tumor pathophysiology and should be considered as a potential biomarker when implementing MET targeted clinical trials.

Receptor status change from primary to residual breast cancer after neoadjuvant chemotherapy and analysis of survival outcomes.

BACKGROUND: To evaluate the frequency of receptor change from pretreatment to residual breast cancer after NCT and their correlation with outcomes. PATIENTS AND METHODS: Three hundred ninety-eight women were identified retrospectively. Estrogen receptor, progesterone receptor, and HER2 were reviewed. Patients were classified as not having receptor change versus any receptor change. Kaplan-Meier was used to estimate survival outcomes according to changes. Cox proportional hazards models were used to determine the association of receptor status changes with outcomes after adjustment for patient and tumor characteristics. RESULTS: One hundred sixty-two (40.7%) patients had a change in at least 1 of the receptors from pretreatment to residual disease. Patients who had no change in receptor status had a significantly greater triple-negative breast cancer (TNBC) rate at baseline (P = .0001). Of the 193 hormone receptor (HR)-positive tumors, 9 (4.7%) and 29 (15.1%) became HER2-positive and TNBC, respectively. Of the 72 HER2-positive tumors, 20 (27.8%) and 9 (12.5%) became HR-positive and TNBC, respectively. Of the 128 TNBC tumors, only 2 (1.6%) and 33 (25.8%) became HER2-positive and HR-positive, respectively. At a median follow up of 40 months, 5-year overall survival (OS) was 73% and 63%; and 5-year relapse-free survival (RFS) was 63% and 48% for patients with or without any receptor change (P = .07 and P = .003), respectively. Any receptor change was associated with better RFS (hazard ratio, 0.63; 95% confidence interval [CI], 0.44-0.9) but not OS. (hazard ratio, 0.79; 95% CI, 0.53-1.18). CONCLUSION: Changes in receptor status between the pretreatment and residual disease after NCT are frequent and appear to be associated with improved RFS because of the receptor stability of TNBC.

Phase II study of gefitinib in patients with advanced salivary gland cancers.

BACKGROUND: The purpose of this study was to determine the antitumor activity of the epidermal growth factor receptor (EGFR) inhibitor gefitinib in patients with recurrent/metastatic salivary gland cancer. METHODS: We conducted a phase II study in adenoid cystic carcinoma (ACC) and non-ACC. Gefitinib was administered 250 mg orally daily. The primary endpoint was tumor response. Secondary endpoints included progression-free survival (PFS), overall survival (OS), and disease control rates. EGFR and human epidermal growth factor receptor 2 (HER2) expression were evaluated and correlated with outcomes. RESULTS: Thirty-seven patients were enrolled in this study, and 36 were evaluable (18 with ACC and 18 with non-ACC). No responses were observed. Median PFS was 4.3 months and 2.1 months, and median OS was 25.9 months and 16 months for patients with ACC and non-ACC, respectively. The disease control rate at 8 weeks was higher in patients with ACC. No unexpected toxicities occurred. EGFR and HER2 overexpression did not correlate with outcomes. CONCLUSION: We did not observe significant clinical activity of gefitinib in advanced salivary gland cancer. NCT00509002.

Outcomes After Multidisciplinary Treatment of Inflammatory Breast Cancer in the Era of Neoadjuvant HER2-directed Therapy.

OBJECTIVES: We previously reported survival trends among patients with inflammatory breast cancer (IBC) over a 30-year period before 2005. Here we evaluated survival outcomes for women with IBC diagnosed before or after October 2006, in the era of HER2-directed therapy and after opening a dedicated multidisciplinary IBC clinic. METHODS: We retrospectively identified and reviewed 260 patients with newly diagnosed IBC without distant metastasis, 168 treated before October 2006 and 92 treated afterward. Most patients received anthracycline and taxane-based neoadjuvant chemotherapy, mastectomy, and postmastectomy radiation. Survival outcomes were compared between the 2 groups. RESULTS: Median follow-up time was 29 months for the entire cohort (39 and 24 mo for patients treated before and after October 2006). Patients treated more recently were more likely to have received neoadjuvant HER2-directed therapy for HER2-positive tumors (100% vs. 54%, P=0.001). No differences were found in receipt of hormone therapy. Three-year overall survival rates were 63% for those treated before and 82% for those treated after October 2006 (log-rank P=0.02). Univariate Cox analysis demonstrated better overall survival among patients treated after October 2006 than among those treated beforehand (hazard ratio [HR] 0.5; 95% confidence interval [CI], 0.34-0.94); a trend toward improved survival was noted in the multivariate analysis (HR=0.47; 95% CI, 0.19-1.16; P=0.10). Significant factors in the multivariate model included HER2-directed therapy (HR=0.38; 95% CI, 0.17-0.84; P=0.02) and estrogen receptor positivity (HR=0.32; 95% CI, 0.14-0.74; P=0.01). CONCLUSIONS: Survival improved in the context of the IBC clinic and prompt initiation of neoadjuvant HER2-directed therapeutics.

Loss of heterozygosity at the CYP2D6 locus in breast cancer: implications for germline pharmacogenetic studies.

BACKGROUND: Controversy exists regarding the impact of CYP2D6 genotype on tamoxifen responsiveness. We examined loss of heterozygosity (LOH) at the CYP2D6 locus and determined its impact on genotyping error when tumor tissue is used as a DNA source. METHODS: Genomic tumor data from the adjuvant and metastatic settings (The Cancer Genome Atlas [TCGA] and Foundation Medicine [FM]) were analyzed to characterize the impact of CYP2D6 copy number alterations (CNAs) and LOH on Hardy Weinberg equilibrium (HWE). Additionally, we analyzed CYP2D6 *4 genotype from formalin-fixed paraffin-embedded (FFPE) tumor blocks containing nonmalignant tissue and buccal (germline) samples from patients on the North Central Cancer Treatment Group (NCCTG) 89-30-52 tamoxifen trial. All statistical tests were two-sided. RESULTS: In TCGA samples (n =627), the CYP2D6 LOH rate was similar in estrogen receptor (ER)-positive (41.2%) and ER-negative (35.2%) but lower in HER2-positive tumors (15.1%) (P < .001). In FM ER+ samples (n = 290), similar LOH rates were observed (40.8%). In 190 NCCTG samples, the agreement between CYP2D6 genotypes derived from FFPE tumors and FFPE tumors containing nonmalignant tissue was moderate (weighted Kappa = 0.74; 95% CI = 0.63 to 0.84). Comparing CYP2D6 genotypes derived from buccal cells to FFPE tumor DNA, CYP2D6*4 genotype was discordant in six of 31(19.4%). In contrast, there was no disagreement between CYP2D6 genotypes derived from buccal cells with FFPE tumors containing nonmalignant tissue. CONCLUSIONS: LOH at the CYP2D6 locus is common in breast cancer, resulting in potential misclassification of germline CYP2D6 genotypes. Tumor DNA should not be used to determine germline CYP2D6 genotype without sensitive techniques to detect low frequency alleles and quality control procedures appropriate for somatic DNA.

cMET Activation and EGFR-Directed Therapy Resistance in Triple-Negative Breast Cancer.

BACKGROUND: EGFR expression and pathway activation are common in triple-negative breast cancer (TNBC). However, anti-EGFR therapies have not been effective in these patients. We aimed to study the efficacy of targeting MET in overcoming resistance to EGFR therapy in TNBC cell lines. METHODS: TNBC lines (MDA-MB-468, HCC-1395, and MDA-MB-231), and a hormone receptor-positive breast cancer line (T47D) were stimulated with epidermal growth factor (EGF) and hepatocyte growth factor (HGF). Lines were then treated with different concentrations of EGFR inhibitors (gefitinib or cetuximab), with or without a MET tyrosine kinase inhibitor (EMD 1214063). Proliferation was measured by MTS assay, in soft agar and with a matrigel assay. Synergy was measured with Calcusyn. Protein expression and signaling were examined with immunoblotting. RESULTS: There was activation of ligand-receptor-downstream signaling pathways in MDA-MB-468 and HCC-1395 upon stimulation with EGF and HGF. In these cell lines, we observed synergism when combining EGFR and MET inhibitors. These results were observed across assays. In western blotting, combination therapy resulted in abrogation of pAKT and pMAPK while monotherapy did not. CONCLUSION: Our data demonstrate that dual EGFR/MET inhibition is synergistic in TNBC. Targeting both EGFR and MET receptors may provide an effective therapeutic strategy in TNBC.