[Show abstract][Hide abstract] ABSTRACT: Obesity increases the risk of cancer death among postmenopausal women with estrogen receptor-positive (ER+) breast cancer, but the direct evidence for the mechanisms is lacking. The purpose of this study is to demonstrate direct evidence for the mechanisms mediating this epidemiologic phenomenon.
Journal of the National Cancer Institute. 07/2014; 106(7).
[Show abstract][Hide abstract] ABSTRACT: Background: PI3K/Akt/mTOR signaling is being actively pursued as a therapeutic target for breast cancer. We sought to determine if tumor heterogeneity and biospecimen variables affect the evaluation of PI3K/Akt/mTOR pathway markers. Methods: Intraoperative image-guided core-needle biopsies (CNB), and central and peripheral surgical tumor specimens were prospectively collected in 53 patients with invasive breast cancer. Specimens were assessed with reverse phase protein arrays (RPPA) and immunohistochemistry (IHC). Results: There was a moderate or strong correlation between the expression of 149 (97%) of the 154 different RPPA markers in the center and periphery. Correlation was higher for smaller tumors, in patients who did not undergo neoadjuvant therapy, and with shorter cold ischemia time. Of 154 markers, 132 (86%) were not statistically different between the center and periphery, and 97 (63%) were not different between the CNB and the surgical specimen (average of the central and peripheral specimen). pAkt S473 and PTEN had a significant correlation between central and peripheral specimens, and between CNB and surgical specimen. However, pAkt S473, pS6 S235/236 and pS6 240/244 levels were significantly higher in CNB than the central specimens both by RPPA and by IHC. Conclusions: Most individual proteomic biomarkers studied do not have significant intratumoral heterogeneity. However, protein and phosphoprotein levels are affected by biospecimen type and other preanalytic variables. PI3K pathway activation is greater in CNB compared to post-excision surgical samples suggesting a potential loss of phosphorylation during surgical manipulation, or with cold ischemia of surgical specimens.
Clinical cancer research : an official journal of the American Association for Cancer Research. 06/2014;
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to assess the frequency of potentially actionable genomic alterations in breast cancer that could be targeted with approved agents or investigational drugs in clinical trials using a next-generation sequencing-based genomic profiling assay performed in a Clinical Laboratory Improvement Amendments-certified and College of American Pathologists-accredited commercial laboratory.Methods.Fifty-one breast cancers were analyzed, including primary tumor biopsies of 33 stage I-II and 18 stage IV cancers (13 soft tissue, 3 liver, and 2 bone metastases). We assessed 3,230 exons in 182 cancer-related genes and 37 introns in 14 genes often rearranged in cancer for base substitutions, indels, copy number alterations, and gene fusions. The average median sequencing depth was 1,154×.Results.We observed 158 genomic alterations in 55 genes in 48 of 51 (94%) tumors (mean 3.1, range 0-9). The average number of potentially therapeutically relevant alterations was similar in primary (1.6, range 0-4) and in heavily pretreated metastatic cancers (2.0, range 0-4) (p = .24). The most common actionable alterations were in PIK3CA (n = 9, phosphatidylinositol 3-kinase [PI3K]/mammalian target of rapamycin [mTOR] inhibitors), NF1 (n = 7, PI3K/mTOR/mitogen-activated protein kinase inhibitors), v-akt murine thymoma viral oncogene homolog 1-3 (n = 7, PI3K/mTOR/AKT inhibitors), BRCA1/2 (n = 6, poly[ADP-ribose] polymerase inhibitors), and CCND1,2 and CCNE (n = 8)/cycline dependent kinase (CDK)6 (n = 1) (CDK4/6 inhibitors), KIT (n = 1, imatinib/sunitinib), ALK (n = 1, crizotinib), FGFR1,2 (n = 5, fibroblast growth factor receptor inhibitors), and EGFR (n = 2, epidermal growth factor receptor inhibitors). Our sequencing assay also correctly identified all six cases with HER2 (ERBB2) amplification by fluorescence in situ hybridization when tumor content was adequate. In addition, two known activating HER2 mutations were identified, both in unamplified cases.Conclusion.Overall, 84% of cancers harbored at least one genomic alteration linked to potential treatment options. Systematic evaluation of the predictive value of these genomic alterations is critically important for further progress in this field.
[Show abstract][Hide abstract] ABSTRACT: Everolimus synergistically enhances taxane-induced cytotoxicity in breast cancer cells in-vitro and in-vivo in addition to demonstrating a direct antiproliferative activity. We aim to determine pharmacodynamics (PD) changes and response of adding everolimus to standard neoadjuvant chemotherapy in triple-negative breast cancer (TNBC).
Phase II study in patients with primary TNBC randomized to T-FEC (paclitaxel 80 mg/m2 IV weekly for 12 weeks, followed by 5FU 500 mg/m2, epirubicin 100 mg/m2, and cyclophosphamide 500 mg/m2 every 3 weeks for 4 cycles) vs. TR-FEC (paclitaxel 80 mg/m2 IV and everolimus 30 mg PO weekly for 12 weeks, followed by FEC). Tumor samples were collected to assess molecular changes in the PI3K/AKT/mTOR pathway, at baseline, 48-hours, 12-weeks and at surgery by reverse phase protein arrays (RPPA). Clinical endpoints included 12-week clinical response rate (12wk RR), pathological complete response (pCR), and toxicity.
62 patients were registered, and 50 were randomized, 27 received T-FEC and 23 received TR-FEC. Median age was 48 (range 31-75). There was downregulation of the mTOR pathway at 48-hours in the TR-FEC arm. 12wk RR by ultrasound were 29.6% vs. 47.8%, (P=0.075), and pCR were 25.9% vs. 30.4% (P=0.76) for T-FEC and TR-FEC, respectively. mTOR downregulation at 48 hours did not correlate with 12wk RR in the TR-FEC group (P=0.58). Main NCI grade 3/4 toxicities included anemia, neutropenia, rash/desquamation, vomiting in both arms. There was one case of grade 3 pneumonitis in the TR-FEC arm. No grade 3/4 stomatitis occurred.
The addition of everolimus to paclitaxel was well tolerated. Everolimus downregulated mTOR signaling but downregulation of mTOR at 48 hours did not correlate with 12wk RR in the TR-FEC group.
[Show abstract][Hide abstract] ABSTRACT: The goal of this analysis was to develop a computational tool that integrates the totality of gene expression, DNA copy number, and sequence abnormalities in individual cancers in the framework of biological processes. We used the hierarchical structure of the gene ontology (GO) database to create a reference network and projected mRNA expression, DNA copy number and mutation anomalies detected in single samples into this space. We applied our method to 59 breast cancers where all three types of molecular data were available. Each cancer had a large number of disturbed biological processes. Locomotion, multicellular organismal process, and signal transduction pathways were the most commonly affected GO terms, but the individual molecular events were different from case-to-case. Estrogen receptor-positive and -negative cancers had different repertoire of anomalies. We tested the functional impact of 27 mRNAs that had overexpression in cancer with variable frequency (<2-42 %) using an siRNA screen. Each of these genes inhibited cell growth in at least some of 18 breast cancer cell lines. We developed a free, on-line software tool ( http://netgoplot.org ) to display the complex genomic abnormalities in individual cancers in the biological framework of the GO biological processes. Each cancer harbored a variable number of pathway anomalies and the individual molecular events that caused an anomaly varied from case-to-case. Our in vitro experiments indicate that rare case-specific molecular abnormalities can play a functional role and driver events may vary from case-to-case depending on the constellation of other molecular anomalies.
Breast Cancer Research and Treatment 03/2014; · 4.47 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Guidelines for the use of chemotherapy and endocrine therapy recently recommended that estrogen receptor (ER) status be considered positive if ≥1% of tumor cells demonstrate positive nuclear staining by immunohistochemistry. In clinical practice, a range of thresholds are used; a common one is 10% positivity. Data addressing the optimal threshold with regard to the efficacy of endocrine therapy are lacking. In this study, we compared patient, tumor, treatment and survival differences among breast cancer patients using ER-positivity thresholds of 1% and 10%.
The study population consisted of patients with primary breast carcinoma treated at our center from January 1990 to December 2011 and whose records included complete data on ER status. Patients were separated into three groups: ≥10% positive staining for ER (ER-positive ≥10%), 1-9% positive staining for ER (ER-positive 1-9%) and <1% positive staining (ER-negative).
Of 9,639 patients included, 80.5% had tumors that were ER-positive ≥10%, 2.6% had tumors that were ER-positive 1-9% and 16.9% had tumors that were ER-negative. Patients with ER-positive 1-9% tumors were younger with more advanced disease compared with patients with ER-positive ≥10% tumors. At a median follow-up of 5.1 years, patients with ER-positive 1-9% tumors had worse survival rates than did patients with ER-positive ≥10% tumors, with and without adjustment for clinical stage and grade. Survival rates did not differ significantly between patients with ER-positive 1-9% and ER-negative tumors.
Patients with tumors that are ER-positive 1-9% have clinical and pathologic characteristics different from those with tumors that are ER-positive ≥ 10%. Similar to patients with ER-negative tumors, those with ER-positive 1-9% disease do not appear to benefit from endocrine therapy; further study of its clinical benefit in this group is warranted. Also, there is a need to better define which patients of this group belong to basal or luminal subtypes.
[Show abstract][Hide abstract] ABSTRACT: Background
Tissue handling can alter global gene expression potentially affecting the analytical performance of genomic signatures, but such effects have not been systematically evaluated.
Tissue samples from 11 previously untreated breast tumors were minced and aliquots were either snap frozen or placed in RNAlater immediately or after 20, 40, 60, 120 or 180 minutes at room temperature. RNA was profiled on Affymetrix HG-U133A arrays. We used probe-set-wise hierarchical models to evaluate the effect of preservation method on transcript expression and linear mixed effects models to assess the effect of cold ischemic delay on the expression of individual probe sets. Gene set enrichment analysis identified pathways overrepresented in the affected transcripts. We combined the levels of 41 most sensitive transcripts to develop an index of ischemic stress.
Concordance in global gene expression between the baseline and 40 min delay was higher for samples preserved in RNAlater (average concordance correlation coefficient CCC = 0.92 compared to 0.88 for snap frozen). Overall, 481 transcripts (3%) were significantly affected by the preservation method, most of them involved in processes important in cancer. Prolonged cold ischemic delay of up to 3 hours induced marginal global gene expression changes (average CCC=0.90 between baseline and 3 hour delay). However 41 transcripts were significantly affected by cold ischemic delay. Among the induced transcripts were stress response genes, apoptotic response genes; among the downregulated were genes involved in metabolism, protein processing and cell cycle regulation. An index combining the expression levels of these genes was proportional to the cold ischemic delay.
Prolonged cold ischemia induces significant transcriptional changes in a small subset of transcripts in the tissue. Furthermore, the expression level of about 3% of the transcripts is affected by the preservation method. These sensitive transcripts should not be included in genomic signatures for more reliable analytical performance.
[Show abstract][Hide abstract] ABSTRACT: We examined estrogen receptor (ER) mRNA expression and molecular subtypes in stage I-III breast cancers that are progesterone receptor (PR) positive but ER and HER2 negative by immunohistochemistry (IHC) or fluorescent in situ hybridization. The ER, PR, and HER2 status was determined by IHC as part of routine clinical assessment (N = 501). Gene expression profiling was done with the Affymetrix U133A gene chip. We compared expressions of ESR1 and MKI67 mRNA, distribution of molecular subtypes by the PAM50 classifier, the sensitivity to endocrine therapy index, and the DLDA30 chemotherapy response predictor signature among ER/PR-positive (n = 223), ER-positive/PR-negative (n = 73), ER-negative/PR-positive (n = 20), and triple-negative (n = 185) cancers. All patients received neoadjuvant chemotherapy with an anthracycline and taxane and had adjuvant endocrine therapy only if ER or PR > 10 % positive. ESR1 expression was high in 25 % of ER-negative/PR-positive, in 79 % of ER-positive/PR-negative, in 96 % of ER/PR-positive, and in 12 % of triple-negative cancers by IHC. The average MKI67 expression was significantly higher in the ER-negative/PR-positive and triple-negative cohorts. Among the ER-negative/PR-positive patients, 15 % were luminal A, 5 % were Luminal B, and 65 % were basal like. The relapse-free survival rate of ER-negative/PR-positive patients was equivalent to ER-positive cancers and better than the triple-negative cohort. Only 20-25 % of the ER-negative/PR-positive tumors show molecular features of ER-positive cancers. In this rare subset of patients (i) a second RNA-based assessment may help identifying the minority of ESR1 mRNA-positive, luminal-type cancers and (ii) the safest clinical approach may be to consider both adjuvant endocrine and chemotherapy.
Breast Cancer Research and Treatment 12/2013; · 4.47 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background: Differences in gene or protein expression patterns between breast cancers according to race/ethnicity and cancer subtype. Methods: Transcriptional profiling was performed using Affymetrix HG-U133A platform in 376 patients and reverse phase protein array analysis (RPPA) was done for 177 proteins in 255 patients from a separate cohort. Unsupervised clustering was conducted, as well as supervised comparison by race and tumor subtype. Standard statistical methods, BRB-Array tools and Ingenuity Pathways software packages were used to analyze the data. Results: Median age was 50 years in both cohorts. In the RPPA cohort 54.5% of the tumors were HR-positive, 20.7% HER2-positive and 24.71% triple-negative (TNBC). One hundred and forty-seven (57.6%), 47 (18.43%), 46 (18.1%) of the patients were White, Hispanic and Black, respectively. Unsupervised hierarchal clustering of the protein expression data showed no distinct clusters by race (p-values were 0.492, 0.489 and 0.494 for the HR-positive, HER2-positive and TNBC tumors respectively). In the gene expression cohort, 54.2% of the tumors were HR-positive, 16.5% HER2-positive and 29.3% TNBC. Two hundred and sixteen (57.5%), 111 (29.52%), and 32 (8.52%) patients were white, Hispanic and black, respectively. No probe set with an FDR < 0.05 showed an association with race by breast cancer subtype; similar results were obtained using pathway and gene set enrichment analysis methods. Conclusions: we did not detect significant variation in RNA or protein expression comparing different race/ethnicity groups of women with breast cancer Impact: More research on the complex network of factors that result in outcomes differences among race/ethnicities is needed.
Cancer Epidemiology Biomarkers & Prevention 12/2013; · 4.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Inflammatory breast cancer (IBC) is an aggressive disease. To date, no molecular feature reliably predicts either the response to chemotherapy (CT) or the survival. Using DNA microarrays, we searched for multigene predictors.
The World IBC Consortium generated whole-genome expression profiles of 137 IBC and 252 non-IBC (nIBC) samples. We searched for transcriptional profiles associated with pathological complete response (pCR) to neoadjuvant anthracycline-based CT and distant metastasis-free survival (DMFS) in respective subsets of 87 and 106 informative IBC samples. Correlations were investigated with predictive and prognostic gene expression signatures published in nIBC (nIBC-GES). Supervised analyses tested genes and activation signatures of 19 biological pathways and 234 transcription factors.
Three of five tested prognostic nIBC-GES and the two tested predictive nIBC-GES discriminated between IBC with and without pCR, as well as two interferon activation signatures. We identified a 107-gene signature enriched for immunity-related genes that distinguished between responders and nonresponders in IBC. Its robustness was demonstrated by external validation in three independent sets including two IBC sets and one nIBC set, with independent significant predictive value in IBC and nIBC validation sets in multivariate analysis. We found no robust signature associated with DMFS in patients with IBC, and neither of the tested prognostic GES, nor the molecular subtypes were informative, whereas they were in our nIBC series (220 stage I-III informative samples).
Despite the relatively small sample size, we show that response to neoadjuvant CT in IBC is, as in nIBC, associated with immunity-related processes, suggesting that similar mechanisms responsible for pCR exist. Analysis of a larger IBC series is warranted regarding the correlation of gene expression profiles and DMFS.
[Show abstract][Hide abstract] ABSTRACT: Because of its high rate of metastasis, inflammatory breast cancer (IBC) has a poor prognosis compared with non-inflammatory types of breast cancer (non-IBC). In a recent study, Lehmann and colleagues identified seven subtypes of triple-negative breast cancer (TNBC). We hypothesized that the distribution of TNBC subtypes differs between TN-IBC and TN-non-IBC. We determined the subtypes and compared clinical outcomes by subtype in TN-IBC and TN-non-IBC patients.
We determined TNBC subtypes in a TNBC cohort from the World IBC Consortium for which IBC status was known (39 cases of TN-IBC; 49 cases of TN-non-IBC). We then determined the associations between TNBC subtypes and IBC status and compared clinical outcomes between TNBC subtypes.
We found the seven subtypes exist in both TN-IBC and TN-non-IBC. We found no association between TNBC subtype and IBC status (P = 0.47). TNBC subtype did not predict recurrence-free survival. IBC status was not a significant predictor of recurrence-free or overall survival in the TNBC cohort.
Our data show that, like TN-non-IBC, TN-IBC is a heterogeneous disease. Although clinical characteristics differ significantly between IBC and non-IBC, no unique IBC-specific TNBC subtypes were identified by mRNA gene expression profiles of the tumor. Studies are needed to identify the subtle molecular or microenvironmental differences that contribute to the differing clinical behaviors between TN-IBC and TN-non-IBC.
Breast cancer research: BCR 11/2013; 15(6):R112. · 5.87 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In breast cancer, immunohistochemical assessment of proliferation using the marker Ki67 has potential use in both research and clinical management. However, lack of consistency across laboratories has limited Ki67's value. A working group was assembled to devise a strategy to harmonize Ki67 analysis and increase scoring concordance. Toward that goal, we conducted a Ki67 reproducibility study.
Eight laboratories received 100 breast cancer cases arranged into 1-mm core tissue microarrays-one set stained by the participating laboratory and one set stained by the central laboratory, both using antibody MIB-1. Each laboratory scored Ki67 as percentage of positively stained invasive tumor cells using its own method. Six laboratories repeated scoring of 50 locally stained cases on 3 different days. Sources of variation were analyzed using random effects models with log2-transformed measurements. Reproducibility was quantified by intraclass correlation coefficient (ICC), and the approximate two-sided 95% confidence intervals (CIs) for the true intraclass correlation coefficients in these experiments were provided.
Intralaboratory reproducibility was high (ICC = 0.94; 95% CI = 0.93 to 0.97). Interlaboratory reproducibility was only moderate (central staining: ICC = 0.71, 95% CI = 0.47 to 0.78; local staining: ICC = 0.59, 95% CI = 0.37 to 0.68). Geometric mean of Ki67 values for each laboratory across the 100 cases ranged 7.1% to 23.9% with central staining and 6.1% to 30.1% with local staining. Factors contributing to interlaboratory discordance included tumor region selection, counting method, and subjective assessment of staining positivity. Formal counting methods gave more consistent results than visual estimation.
Substantial variability in Ki67 scoring was observed among some of the world's most experienced laboratories. Ki67 values and cutoffs for clinical decision-making cannot be transferred between laboratories without standardizing scoring methodology because analytical validity is limited.
[Show abstract][Hide abstract] ABSTRACT: IMPORTANCE Sentinel lymph node (SLN) surgery provides reliable nodal staging information with less morbidity than axillary lymph node dissection (ALND) for patients with clinically node-negative (cN0) breast cancer. The application of SLN surgery for staging the axilla following chemotherapy for women who initially had node-positive cN1 breast cancer is unclear because of high false-negative results reported in previous studies. OBJECTIVE To determine the false-negative rate (FNR) for SLN surgery following chemotherapy in women initially presenting with biopsy-proven cN1 breast cancer. DESIGN, SETTING, AND PATIENTS The American College of Surgeons Oncology Group (ACOSOG) Z1071 trial enrolled women from 136 institutions from July 2009 to June 2011 who had clinical T0 through T4, N1 through N2, M0 breast cancer and received neoadjuvant chemotherapy. Following chemotherapy, patients underwent both SLN surgery and ALND. Sentinel lymph node surgery using both blue dye (isosulfan blue or methylene blue) and a radiolabeled colloid mapping agent was encouraged. MAIN OUTCOMES AND MEASURES The primary end point was the FNR of SLN surgery after chemotherapy in women who presented with cN1 disease. We evaluated the likelihood that the FNR in patients with 2 or more SLNs examined was greater than 10%, the rate expected for women undergoing SLN surgery who present with cN0 disease. RESULTS Seven hundred fifty-six women were enrolled in the study. Of 663 evaluable patients with cN1 disease, 649 underwent chemotherapy followed by both SLN surgery and ALND. An SLN could not be identified in 46 patients (7.1%). Only 1 SLN was excised in 78 patients (12.0%). Of the remaining 525 patients with 2 or more SLNs removed, no cancer was identified in the axillary lymph nodes of 215 patients, yielding a pathological complete nodal response of 41.0% (95% CI, 36.7%-45.3%). In 39 patients, cancer was not identified in the SLNs but was found in lymph nodes obtained with ALND, resulting in an FNR of 12.6% (90% Bayesian credible interval, 9.85%-16.05%). CONCLUSIONS AND RELEVANCE Among women with cN1 breast cancer receiving neoadjuvant chemotherapy who had 2 or more SLNs examined, the FNR was not found to be 10% or less. Given this FNR threshold, changes in approach and patient selection that result in greater sensitivity would be necessary to support the use of SLN surgery as an alternative to ALND. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00881361.
JAMA The Journal of the American Medical Association 10/2013; 310(14):1455-1461. · 29.98 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: DNA repair pathways can enable tumor cells to survive DNA damage induced by chemotherapy and thus provide prognostic and/or predictive value. We evaluated Affymetrix gene expression profiles for 145 DNA repair genes in untreated breast cancer (BC) patients (n = 684) and BC patients treated with regimens containing neoadjuvant taxane/anthracycline (n = 294) or anthracycline (n = 210). We independently assessed estrogen receptor (ER)-positive/HER2-negative, HER2-positive, and ER-negative/HER2-negative subgroups for differential expression, bimodal distribution, and the prognostic and predictive value of DNA repair gene expression. Twenty-two genes were consistently overexpressed in ER-negative tumors, and five genes were overexpressed in ER-positive tumors, but no differences in expression were associated with HER2 status. In ER-positive/HER2-negative tumors, the expression of nine genes (BUB1, FANCI, MNAT1, PARP2, PCNA, POLQ, RPA3, TOP2A, and UBE2V2) was associated with poor prognosis, and the expression of one gene (ATM) was associated with good prognosis. Furthermore, the prognostic value of specific genes did not correlate with proliferation. A few genes were associated with chemotherapy response in BC subtypes and treatment-specific manner. In ER-negative/HER2-negative tumors, the MSH2, MSH6, and FAN1 (previously MTMR15) genes were associated with pathological complete response and residual invasive cancer in taxane/anthracycline-treated patients. Conversely, PMS2 expression was associated with residual invasive cancer in treatments using anthracycline as a single agent. In HER2-positive tumors, TOP2A was associated with patient response to anthracyclines but not to taxane/anthracycline regimens. In genes expressed in a bimodal fashion, RECQL4 was significantly associated with clinical outcome. In vitro studies showed that defects in RECQL4 impair homologous recombination, sensitizing BC cells to DNA-damaging agents.
[Show abstract][Hide abstract] ABSTRACT: We examined if a combination of proliferation markers and estrogen receptor (ER) activity could predict early versus late relapses in ER-positive breast cancer and inform the choice and length of adjuvant endocrine therapy.
Baseline affymetrix gene-expression profiles from ER-positive patients who received no systemic therapy (n = 559) or adjuvant tamoxifen for 5 years (cohort-1: n = 683, cohort-2: n = 282) and from 58 patients treated with neoadjuvant letrozole for 3 months (gene-expression available at baseline, 14 and 90 days) were analyzed. A proliferation score based on the expression of mitotic kinases (MKS) and an ER-related score (ERS) adopted from Oncotype DX(R) were calculated. The same analysis was performed using the Genomic Grade Index as proliferation marker and the luminal gene score from the PAM50 classifier as measure of estrogen-related genes. Median values were used to define low and high marker groups and four combinations were created. Relapses were grouped into time cohorts of 0--2.5, 0--5, >5-10 years.
In the overall 10 years period, the proportional hazards assumption was violated for several biomarker groups indicating time-dependent effects. In tamoxifen-treated patients Low-MKS/Low-ERS cancers had continuously increasing risk of relapse that was higher after 5 years than Low-MKS/High-ERS cancers [0 to 10 year, HR 3.36; p = 0.013]. High-MKS/High-ERS cancers had low risk of early relapse [0--2.5 years HR 0.13; p = 0.0006], but high risk of late relapse which was higher than in the High-MKS/Low-ERS group [after 5 years HR 3.86; p = 0.007]. The High-MKS/Low-ERS subset had most of the early relapses [0 to 2.5 years, HR 6.53; p < 0.0001] especially in node negative tumors and showed minimal response to neoadjuvant letrozole. These findings were qualitatively confirmed in a smaller independent cohort of tamoxifen-treated patients. Using different biomarkers provided similar results.
Early relapses are highest in highly proliferative/low-ERS cancers, in particular in node negative tumors. Relapses occurring after 5 years of adjuvant tamoxifen are highest among the highly-proliferative/high-ERS tumors although their risk of recurrence is modest in the first 5 years on tamoxifen. These tumors could be the best candidates for extended endocrine therapy.
Breast cancer research: BCR 09/2013; 15(5):R86. · 5.87 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This randomized phase II trial was designed to compare the rate of pathologic complete response (pCR) induced by neoadjuvant cyclophosphamide plus doxorubicin (AC) followed by ixabepilone or paclitaxel in women with early stage breast cancer (BC). Expression of βIII-tubulin as a predictive marker was also evaluated.
Women with untreated, histologically confirmed primary invasive breast adenocarcinoma received four cycles of AC followed by 1:1 randomization to either ixabepilone 40 mg/m(2) (3-hour infusion) every 3 weeks for four cycles ( N: = 148) or weekly paclitaxel 80 mg/m(2) (1-hour infusion) for 12 weeks ( N: = 147). All patients underwent a core needle biopsy of the primary cancer for molecular marker analysis prior to chemotherapy. βIII-Tubulin expression was assessed using immunohistochemistry.
There was no significant difference in the rate of pCR in the ixabepilone treatment arm (24.3%; 90% confidence interval [CI], 18.6-30.8) and the paclitaxel treatment arm (25.2%; 90% CI, 19.4-31.7). βIII-Tubulin-positive patients obtained higher pCR rates compared with βIII-tubulin-negative patients in both treatment arms; however, βIII-tubulin expression was not significantly associated with a differential response to ixabepilone or paclitaxel. The safety profiles of both regimens were generally similar, although neutropenia occurred more frequently in the ixabepilone arm (grade 3/4: 41.3% vs. 8.4%). The most common nonhematologic toxicity was peripheral neuropathy.
Neoadjuvant treatment of early stage BC with AC followed by ixabepilone every 3 weeks or weekly paclitaxel was well tolerated with no significant difference in efficacy. Higher response rates were observed among βIII-tubulin-positive patients.
[Show abstract][Hide abstract] ABSTRACT: Background: The goal of this study was to develop a method to quantify intratumor heterogeneity of cancers using gene expression data. We compared gene expression heterogeneity between different molecular subtypes of breast cancer and between basal like cancers with or without pathologic complete response (pCR) to neoadjuvant chemotherapy. Methods: Affymetrix U133A gene expression data of 335 stage I-III breast cancers were analyzed. Molecular class was assigned using the PAM50 predictor. All patients received neoadjuvant chemotherapy. We measured tumor heterogeneity by the Gini index (GI) calculated individually for each case over the expression of all probe sets and random subsets. The GI was used as a metric of inequality of gene expression distributions between cases. The higher the GI, the greater the inequality of the expression distribution. Results: Basal like cancers (n=138) had greater heterogeneity than luminal cancers (n=197) (mean GI values 24.51 vs 23.05, p<0.001) and luminal B (n=71) cancers had greater heterogeneity compared to Luminal A (n=126) cancers (24.49 vs 22.25, p<0.001). Among the basal-like cancers, those with pCR (n=44) had significantly higher heterogeneity compared to cancers with residual disease (RD, n=94) (26.10 vs 23.77, p<0.001). Significant differences in GI between cancer subtypes remained for as low 2500 randomly selected probe sets. Conclusions: Breast cancer subtypes differ in intratumor gene expression heterogeneity. Greater degree of heterogeneity correlate with greater chemotherapy sensitivity. Importantly, among basal-like cancers only the heterogeneity metric differed significantly between cases with pCR or RD but not individual genes expression values or gene signatures.
[Show abstract][Hide abstract] ABSTRACT: The goal of this study was to assess the prognostic value of a 3-gene (TOP2A, FOXM1, and MKI67) proliferation score and use it to risk stratify grade-2, estrogen receptor (ER)-positive breast cancers into low- and high-risk groups. We used 4 different breast cancer gene expression datasets including two cohorts of patients who received no systemic adjuvant therapy (Mainz: n = 206, TRANSBIG: n = 134) and two other cohorts that received adjuvant tamoxifen (JBI: n = 227, MDACC/SET: n = 192). We compared individual and combined expression values of the 3 genes between grade 1, 2, and 3 tumors and plotted distant metastasis-free survival (DMFS) curves by the 3-gene score for grade-2 cancers. We compared the prognostic value of the 3-gene score to the Genomic Grade Index (GGI). The individual and combined expression of TOP2A, FOXM1, and MKI67 were significantly different between the 3 histological grade groups with the highest expression in grade-3 and the lowest in grade-1 cancers. Expression levels were variable in grade-2 cancers. Grade-2 tumors with high expression of the 3 genes (>median) showed significantly worse DMFS in one prognostic and one tamoxifen-treated set and showed a similar but non-significant trend for worse survival in the remaining two datasets. The 3-gene score performed equally well in risk stratification as the GGI. A 3-gene proliferation score shows similar prognostic value as the GGI in ER-positive, grade-2 cancers and may serve as basis for a PCR-based assay that could aid prognostic prediction for clinically intermediate-risk cancers.
Breast Cancer Research and Treatment 03/2013; · 4.47 Impact Factor