Benefit Of Taxanes Research Articles

Predictive gene expression profile for adjuvant taxane benefit in breast cancer in the MATADOR trial

The primary objective of the prospective, randomized, multicenter, phase 3 biomarker Microarray Analysis in breast cancer to Taylor Adjuvant Drugs Or Regimens trial (MATADOR: ISRCTN61893718) is to generate a gene expression profile that can predict benefit from either docetaxel, doxorubicin, and cyclophosphamide (TAC) or dose-dense scheduled doxorubicin and cyclophosphamide (ddAC). Patients with a pT1-3, pN0-3 tumor were randomized 1:1 between ddAC and TAC. The primary endpoint was a gene profile-treatment interaction for recurrence-free survival (RFS). We observed 117 RFS events in 664 patients with a median follow-up of 7 years. Hallmark gene set analyses showed significant association between enrichment in immune-related gene expression and favorable outcome after TAC in hormone receptor-negative, human epidermal growth factor receptor 2 (HER2)-negative breast cancer (BC) (triple-negative breast cancer [TNBC]). We validated this association in TNBC patients treated with TAC on H&E slides; stromal tumor-infiltrating lymphocytes (sTILs) ≥20% was associated with longer RFS (hazard ratio 0.18, p= 0.01), while in patients treated with ddAC no difference in RFS was seen (hazard ratio 0.92, p= 0.86, p interaction= 0.02).

FER regulates endosomal recycling and is a predictor for adjuvant taxane benefit in breast cancer.

Elevated expression of non-receptor tyrosine kinase FER is an independent prognosticator that correlates with poor survival of high-grade and basal/triple-negative breast cancer (TNBC) patients. Here, we show that high FER levels are also associated with improved outcomes after adjuvant taxane-based combination chemotherapy in high-risk, HER2-negative patients. In TNBC cells, we observe a causal relation between high FER levels and sensitivity to taxanes. Proteomics and mechanistic studies demonstrate that FER regulates endosomal recycling, a microtubule-dependent process that underpins breast cancer cell invasion. Using chemical genetics, we identify DCTN2 as a FER substrate. Our work indicates that the DCTN2 tyrosine 6 is essential for the development of tubular recycling domains in early endosomes and subsequent propagation of TNBC cell invasion in 3D. In conclusion, we show that high FER expression promotes endosomal recycling and represents a candidate predictive marker for the benefit of adjuvant taxane-containing chemotherapy in high-risk patients, including TNBC patients.

Abstract LB203: FER regulates endosomal recycling and is a candidate predictor for taxane benefit in breast cancer

Abstract To this day, targeted treatment options for patients with triple negative metastatic breast cancer (TNBC) are still virtually absent. Previously, we showed that elevated expression of the tyrosine kinase FER is an independent prognosticator that correlates with poor survival of high-grade and basal/TNBC patients. Here, we show that high FER levels are also associated with improved outcome after adjuvant taxane-based combination chemotherapy, in high-risk, HER2-negative patients. In TNBC cells, we observed a causal relation between high FER levels and sensitivity to taxanes. Our proteomics and mechanistic studies demonstrated that FER regulates endosomal recycling, a microtubule-dependent process that underpins breast cancer cell invasion. Using chemical genetics, we identified DCTN2 as a novel FER substrate. Our work indicates that the DCTN2 tyrosine 6 is essential for tubular recycling domains development in early endosomes and subsequent propagation of TNBC cell invasion in 3D. In conclusion, we show that high FER expression promotes endosomal recycling and represents a candidate predictive marker for benefit of adjuvant taxane-containing chemotherapy in high-risk patients, including TNBC patients. Citation Format: Sandra Tavares, Nalan Liv, Milena Pasolli, Mark Opdam, Max Ratze, Manuel Saornil, Lilian Sluimer, Rutger Hengeveld, Robert van Es, Erik van Werkhoven, Harmjan Vos, Holger Rehmann, Boudewijn Burgering, Hendrika Oosterkamp, Susanne Lens, Judith Klumperman, Sabine Linn, Patrick Derksen. FER regulates endosomal recycling and is a candidate predictor for taxane benefit in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB203.

GRP78 expression in peripheral blood mononuclear cells is a new predictive marker for the benefit of taxanes in breast cancer neoadjuvant treatment

BackgroundBreast cancer treatment is tailored to the specific cancer subtype. Often, systemic treatment is given prior to surgery. Chemotherapy induces significant endoplasmic reticulum (ER) stress-mediated cell death and upregulation of 78-kDa glucose-regulated protein (GRP78). We hypothesized that chemotherapy induces ER stress not only in the tumor tissue but also in immune cells, which may affect the response to anti-cancer treatment.MethodsWe determined the surface expression of GRP78 on 15 different peripheral blood mononuclear cell (PBMC) subpopulations in 20 breast cancer patients at three time points of the neoadjuvant treatment, i.e., at baseline, after anthracycline treatment, and after taxanes treatment. For this purpose, we performed flow cytometric analyses and analyzed the data using ANOVA and the Tukey test. Serum cytokine levels were also evaluated, and their levels were correlated with response to treatment using the t-test after log transformation and Mann-Whitney U Wilcoxon W test.ResultsA significant increase in GRP78 expression in PBMCs was documented during the taxane phase, only in patients who achieved pathological complete response (pCR). GRP78-positive clones correlated with increased serum levels of interferon gamma (IFNγ).ConclusionsThe presence of GRP78-positive clones in certain PBMC subpopulations in pCR patients suggests a dynamic interaction between ER stress and immune responsiveness. The correlation of GRP78-positive clones with increased levels of IFNγ supports the idea that GRP78 expression in PBMCs might serve as a new predictive marker to identify the possible benefits of taxanes in the neoadjuvant setting.

Taxanes – The Backbone of Medical Oncology

AbstractDrug development in oncology has witnessed a revolutionary growth from its humble beginning with nitrogen mustard in 1940 to immunotherapy in 1986 (Interferon alpha). The arsenal of cytotoxics is ever increasing, contributing to better survival outcomes and improved quality of life. Over the years, many cytotoxics have fallen out of favor too, due to its side effects and availability of drugs with better efficacy and toxicity profile. Taxane, a microtubule stabilizing agent extracted from the poisonous Yew tree, was discovered in 1964 and came into clinical use in 1992 with its approval for ovarian cancer. This group has grown into a cornerstone of many treatment protocols, spanning multiple tumor types. This review discusses in brief the salient features of cytotoxic agents in this drug group, its history, physico-chemical properties, mechanism of action, pharmacodynamics, and pharmacokinetics. Though the benefits of taxanes are well understood, there are unique problems associated with the use of taxanes and there is an expanding literature on taxane resistance. We briefly look at the resistance mechanisms. There have been significant efforts to circumvent the problems related to conventional taxanes, with an attempt at creating newer carrier molecules and adjunct drugs with taxanes, which is slowly gaining traction in clinical practice.

Association of neuroendocrine (NE) mRNA expression profiling in hormone-sensitive tumors samples with adverse clinical outcome in castration-resistant prostate cancer (CRPC) patients.

165 Background: NE dedifferentiation is associated to clinical aggressiveness and resistance to androgen receptor inhibition in prostate cancer. We investigated impact of a NE expression signature in the clinical outcome of mCRPC patients treated with taxanes. Methods: This is a multicenter retrospective study. A customized panel of 45 NE-related gene signature was tested in total RNA from formalin-fixed paraffin-embedded hormone-sensitive tumor samples, by the nCounter platform (Nanostring Technologies). Patients were grouped according to their molecular profile by unsupervised clustering. Expression levels were correlated with taxanes response and clinical outcome. Independent association with survival was evaluated by multivariate Cox modeling. Results: Eighty seven patients were included in the study, 79 were treated with docetaxel and 8 with cabazitaxel. Median age was 64.8 (44-88.3) years and median follow-up was 20.7 (1.17-74.4) months. High expression of the NE signature was associated with a shorter time of CRPC development (N=60, median 12.8 vs 21.6, HR 2.4, 95%CI 1.3-4.3, P=0.003) and shorter OS from CRPC diagnosis (median 24.1 vs 41.33, HR 2.3, 95%CI 1.4-3.8, P=0.001). Moreover, according to the outcome to taxanes, high NE signature correlated with lower PSA-PFS (median 6.6 vs 10.1 mo P=0.047, HR 1.6, 95%CI 1-2.7, P=0.05) and OS (median 19 vs 22 mo, HR 1.8, 95%CI 1.1-2.8, P=0.014), and it was independently associated to a lower OS (HR 1.9, 95%CI 1.1-3.2, P=0.016). Conclusions: NE-related gene expression in hormone-sensitive tumor samples is associated with adverse clinical outcome and lower taxane benefit in metastatic CRPC patients. Thus, molecular characterization of primary tumors may be useful to guide treatment strategies in metastatic prostate cancer.

Effects of adjuvant chemotherapy in T1N0M0 triple-negative breast cancer

ObjectivesPatients with T1N0M0 breast cancers are considered to have an excellent prognosis, even in triple-negative breast cancer (TNBC), which is often associated with diminished recurrence-free survival (RFS) and overall survival. Chemotherapy remains the only adjuvant treatment for TNBC, but evidence that adjuvant chemotherapy is beneficial for stage T1N0M0 TNBC patients is limited. In this study, we aimed to evaluate the effect of adjuvant chemotherapy and the benefit of taxanes in T1N0M0 TNBC patients. Material and methodsA cohort of 354 consecutive patients with newly diagnosed T1N0M0 TNBC between January 2008 and December 2015 were included from the Fudan University Shanghai Cancer Center. Univariate and multivariate survival analyses were performed to compare patients treated with adjuvant chemotherapy with/without taxane addition. ResultsMedian follow-up was 45 months. Chemotherapy was used in 92.4% of patients. The 5-year estimated RFS rates of patients with and without adjuvant chemotherapy were 94.5% and 83.6%, respectively. In multivariate analysis, adjuvant chemotherapy and a lack of lymphovascular invasion were associated with a significant benefit for RFS. A significant RFS benefit from adjuvant chemotherapy was observed in T1c (hazard ratio, HR = 0.24, 95% CI [0.08–0.76], P = 0.014) but not in T1b (HR = 0.32, 95% CI [0.03–3.18], P = 0.330) subgroups. Addition of taxane to an anthracycline-based regimen was not significantly associated with improved RFS in T1N0M0 TNBC patients. ConclusionAdjuvant chemotherapy improves recurrence-free survival in T1c TNBC patients but not in T1b. Anthracycline-based taxane-free regimens might be sufficient to achieve RFS benefits in T1N0M0 TNBC patients.

1686P - Ability of TMPRSS2-ERG (TE) expression to predict taxane benefit depending on prior abiraterone or enzalutamide therapy in castration-resistant prostate cancer

1686P - Ability of TMPRSS2-ERG (TE) expression to predict taxane benefit depending on prior abiraterone or enzalutamide therapy in castration-resistant prostate cancer

728PD - Impact of AR-V7 protein localization in the prediction of therapeutic benefit of taxanes over androgen receptor signaling inhibitors (ARSi) in metastatic castration resistant prostate cancer (mCRPC)

AR-V7 is a truncated form of the AR lacking the ligand binding domain that activates AR signaling in the absence of androgens. The presence of AR-V7 mRNA in CTCs predicts a poor outcome on the ARSi, abiraterone and enzalutamide. Localization of AR-V7 in the nucleus of CTCs also predicts poor ARSi outcomes, and a treatment-specific interaction that predicted a reduced risk of death if Taxanes vs. ARSi (HR = 0.242, p = 0.0350) are prescribed. Overall, the incidence of nuclear AR-V7 protein was lower than that of AR-V7 mRNA, but more predictive of ARSi outcomes. In a post-hoc analysis of outcomes of samples evaluated with AR-V7 CTC protein we asked if the presence of cytoplasmic AR-V7 protein could explain the difference in prognostic ability of the two tests, and separately, explored the association between non-nuclear AR-V7 and benefit from taxanes over ARSi. 191 blood samples (n = 128 pre-ARSi, n = 63 pre-Taxane) from 161 patients were processed utilizing the Epic Sciences CTC nuclear AR-V7 protein test. Patients were followed up to 29.5 months (range 1.3 to 29.5). Samples were rescored by readers, blinded to outcome to determine the frequency of and outcome with cytoplasmic AR-V7. Inclusion of non-nuclear localized AR-V7 protein as positive scoring criteria increased the incidence of detection in all lines of therapy, an equivalent increase in false positives (PSA responders), and loss of the significance of the treatment-specific survival interaction in multivariate model.Tabled 1AR-V7 LocalizationDetection Rate by Line of Therapy (1st, 2nd, 3rd +)HR of OS on ARSiTherapy Interaction (Taxanes vs. ARSi)Nuclear (alone)3%, 18%, 31%11.5, p < 0.00010.242, p = 0.0350Cytoplasmic (alone)13%, 8%, 12%1.11, p = 0.8441.21, p = 0.838Any (Nuc & Cyto)16%, 26%, 43%4.93, p < 0.00011.04, p = 0.943 Open table in a new tab Including cytoplasmic AR-V7 in the “positive” test definition reduces the prognostic power of the assay and negates the treatment predictive value of AR-V7. Not all AR-V7 signal is equivalent. It remains to be seen if non-nuclear localized AR-V7 protein samples would test positive via mRNA methods.

TLE3 is not a predictive biomarker for taxane sensitivity in the NCIC CTG MA.21 clinical trial

Background:TLE3, a nuclear transcriptional repressor downstream of WNT signalling pathways, has been hypothesised as predictive of benefit from adjuvant taxane.Methods:MA.21 tissue microarrays were constructed from 1097 out of 2104 (52%) patients. TLE3 staining by immunohistochemistry used validated methodology. Continuous TLE3+ (percentage of cells staining positive) was assessed with both visual and automated scoring. The primary objective was to test the predictive effect of TLE3 on relapse-free survival using the MA.21 EC/T and CEF arms and the previously defined cut-point of 30% of cells staining positive in ⩾1 core/tumour.Results:MA.21 patients had 83.2% TLE3 positive (TLE3+) tumours by visual score and 80.6% TLE3+ by automated image analysis while the previously observed rate of TLE3+ cases was 58.6%. TLE3 expression was significantly associated with ER expression (91.2% of ER-positive tumours were TLE3+ P<0.0001). At median 8-year follow-up, there was no evidence of a predictive effect of TLE3 expression with respect to taxane benefit using the established 30% or exploratory quartile cut-points.Conclusions:Proportionately more MA.21 patient tumours than expected were TLE3+. The pre-specified TLE3+ cut-point of 30% was not predictive of taxane benefit. TLE3 expression does not represent a viable biomarker for taxane benefit in breast cancer.

Final 10-year results of the Breast International Group 2–98 phase III trial and the role of Ki67 in predicting benefit of adjuvant docetaxel in patients with oestrogen receptor positive breast cancer

AimBreast International Group (BIG) 2–98 is a randomised phase III trial that tested the effect of adding docetaxel, either in sequence to or in combination with anthracycline-based adjuvant chemotherapy, in women with node-positive breast cancer (BC). Here, we present the 10-year final trial safety and efficacy analyses. We also report an exploratory analysis on the predictive value of Ki67 for docetaxel efficacy, in the BIG 2–98 and using a pooled analysis of three other randomised trials. Patients and methods2887 patients were randomly assigned in a 2×2 trial design to one of four treatments. The primary objective was to evaluate the overall efficacy of docetaxel on disease free survival (DFS). Secondary objectives included comparisons of sequential docetaxel versus sequential control arm, safety and overall survival (OS). Ki67 expression was centrally evaluated by immunohistochemistry. ResultsAfter a median follow-up of 10.1years, the addition of docetaxel did not significantly improve DFS or OS (hazard ratio (HR)=0.91, 95% confidence interval (CI)=0.81–1.04; P=0.16 and HR=0.88, 95% CI=0.76–1.03; P=0.11, respectively). Sequential docetaxel did not improve DFS compared to the sequential control arm (HR=0.86, 95% CI=0.72–1.03; P=0.10). In oestrogen receptor (ER)-positive tumours with Ki67⩾14%, the addition of docetaxel resulted in 5.4% improvement in 10-year OS (P=0.03, test for interaction=0.1). In a multivariate model, there was a trend for improved DFS and OS in ER-positive patients with high Ki67 and treated with docetaxel (HR=0.79, 95% CI=0.63–1.01; P=0.05 and HR=0.76, 95% CI=0.57–1.01; P=0.06, respectively). A pooled analysis of four randomised trials showed a benefit of taxanes in highly proliferative ER-positive disease but not in low proliferating tumours (interaction test P=0.01). ConclusionThe DFS benefit previously demonstrated with sequential docetaxel is no longer observed at 10years. However, an exploratory analysis suggested a benefit of docetaxel in patients with highly proliferative ER-positive BC.

EVALUATION OF THE EXPRESSION OF TLE3 IN SEROUS OVARIAN CANCER

Indications for treatment of ovarian cancer with taxane derivatives requires individualization, and this is necessary to have a reliable marker allowing to determine the rationality of the using of cytostatics. One of the progressive trends in this issue may be related to the immunohistochemical identification in removed tumors of transducing-like protein TLE3, which is a transcriptional repressor that is involved in the differentiation of epithelial cells and carcinogenesis. In the present study retrospectively analyzed 100 patients and prospectively 73 patients with serous ovarian cancer treated in MCCOC from 2007 to2014. In the first stage of treatment all patients underwent debulking surgery followed by adjuvant chemotherapy with platinum and taxanes or cyclophosphamide. Providing of immunohistochemical investigation of removed tumor tissue was carried out with a standard peroxidase-antiperoxidase method. Statistically significant influence of expression of TLE3 on disease-free survival (log-rank = 0.023). Five-year disease-free survival in the group with positive expression of TLE3 was 1.2 times higher than in the group with negative expression of TLE3 (0.490; 95% confidence interval [0.287, 0.837] and 0.261; 95% confidence interval [0.179, 0.380], respectively). An objective response in patients with TLE3-positive tumors was obtained in 93.8%. There were no benefits of taxanes using compared with cyclophosphamide in group of patients with negative expression TLE3. Thus, it is advisable to evaluate the expression of TLE3 to identify groups of patients that are sensitive to chemotherapy with taxanes.

Abstract P4-11-06: TLE3 is not a predictive biomarker for taxane sensitivity in the NCIC CTG MA.21 clinical trial

Abstract Background: TLE3, a nuclear transcriptional repressor downstream of the WNT signaling pathway, has been identified as a candidate predictive biomarker of taxane benefit in early breast cancer. However, robust clinical evidence is required before implementing novel diagnostic biomarkers. We tested the hypothesis that TLE3 predicts for benefit from taxane containing polychemotherapy in the NCIC CTG MA.21 clinical trial. Methods: MA.21 accrued 2104 patients [701 each to cyclophosphamide, epirubicin, and 5 fluorouracil (CEF) and epirubicin and cyclophosphamide with filgrastim and epoetin alfa followed by paclitaxel (EC/T), 702 to doxorubicin and cyclophosphamide followed by paclitaxel (AC/T)] who were followed median 8 years by the final analysis. EC/T and CEF were not significantly different (p= 0.69) while AC/T was inferior to both EC/T and CEF (respectively, p=0.001 and p=0004). Tissue microarrays were constructed from 1097 of the 2104 patients. Patient characteristics were well balanced between those included in the TLE3 analysis and the full trial population. Up to four 0.6 mm tumor cores were stained for TLE3 expression by immunohistochemistry using a previously validated methodology. Continuous visual TLE3 score was the average % positive stain across all cores, while continuous automated score was sum of cells with positive stain/ total cells assessed in all cores. The primary objective used the EC/T (taxane-containing) and CEF (non-taxane; similar dose-density) arms for a test of predictive effect of TLE3 on relapse free survival. TLE3 was positive if &amp;gt;30% of cells stained, the established cut-point, with data available from at least 1 core/tumor. We also examined quartile cut-points, multivariate effects of TLE3, and compared AC/T and CEF. Results: MA.21 patients had 83.2% TLE3+ tumors by visual score and 80.6% TLE3+ by automated image analysis greater than the predicted rate of TLE3 positivity (58.6%) based on prior series and adjusting for clinicopathological features. TLE3 expression was significantly positively associated with ER expression (91.2% of ER+ were TLE3+; p&amp;lt;0.0001). There was no evidence of a predictive effect of TLE3 expression with respect to taxane benefit using the established 30% cut-point, nor quartile cut-points. The treatment and TLE3 interaction term for the EC/T by CEF comparison was not significant (stratified p=0.68, for manual TLE3; p=0.44, for automated TLE3). Conclusions: MA.21 patients had a much higher proportion of TLE3+ tumors than anticipated. Multiple assessments of TLE3 cut-points yielded no evidence that it was predictive of taxane benefit. In our trial TLE3 expression was not a biomarker for taxane benefit (EC/T vs CEF) when using either previously established or common quartile cut-offs for expression in breast cancer. Citation Format: John MS Bartlett, Torsten O Nielsen, Dongxia Gao, Karen A Gelmon, Mary Anne Quintayo, Jane Starczynski, Lei Han, Margot J Burnell, Mark N Levine, Lois E Shepherd, Judy-Anne W Chapman. TLE3 is not a predictive biomarker for taxane sensitivity in the NCIC CTG MA.21 clinical trial [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P4-11-06.

Predictive role of HER2/neu, topoisomerase-II-alpha, and tissue inhibitor of metalloproteinases (TIMP-1) for response to adjuvant taxane-based chemotherapy in patients with intermediate-risk breast cancer: results from the WSG-AGO EC-Doc trial.

Taxane-anthracycline-based adjuvant chemotherapy is standard of care in patients with node-positive breast cancer (BC) but is also associated with severe side effects and significant costs. It is yet unclear, which biomarkers would predict benefit from taxanes and/or general chemoresistance. In this study, we investigate a large cohort of patients with intermediate-risk BC treated within the WSG EC-DOC Trial for the predictive impact of topoisomerase-II-alpha, HER2/neu, and TIMP-1. Tumor tissue was available in a representative cohort of 772 cases of the WSG EC-DOC Trial collective which compared 4xEC-4xDoc versus 6xCEF/CMF. In addition to hormone receptor status and Ki-67, HER2/neu+ and topoisomerase-II-alpha status using fluorescence in situ hybridisation (FISH) and immunohistochemistry, TIMP-1 using immunohistochemistry, and aneuploidy of chromosome 17 using FISH were evaluated and correlated with outcome and taxane benefit. There was significant superiority of EC-Doc over CEF regarding 5-year DFS (90 vs. 80 %, respectively, p = 0.006) particularly in patient subgroups defined by HR+, HER2/neu+, high proliferation (i.e., Ki-67 ≥ 20 %), patient age >50 years old and normal chromosome 17 status, high TIMP-1 and low topoisomerase-II-alpha protein expression. Significant prognostic factors in multivariate analysis were EC-Doc therapy (HR = 0.61; 95 %CI 0.38-0.986), age <50 years old (HR = 1.682; 95 %CI 1.025-2.579), centrally assessed grade 3 (HR = 4.657; 95 %CI 1.809-11.989), and high Ki-67 (HR = 2.232; 95 %CI 1.209-4.121). Interestingly, we observed a significant interaction between treatment arm (EC-Doc vs. CEF) and high topoisomerase-II-alpha protein expression (HR = 0.427; 95 %CI 0.203-0.900) in multivariate interaction analysis. Despite of univariate predictive effect of HER2/neu status among other factors only topoisomerase-II-alpha protein expression was associated with significant benefit from EC-Doc compared to CEF by multivariate interaction analysis.

Assessment of microtubule-associated protein (MAP)-Tau expression as a predictive and prognostic marker in TACT; a trial assessing substitution of sequential docetaxel for FEC as adjuvant chemotherapy for early breast cancer

The TACT trial is the largest study assessing the benefit of taxanes as part of adjuvant therapy for early breast cancer. The goal of this translational study was to clarify the predictive and prognostic value of Tau within the TACT trial. Tissue microarrays (TMA) were available from 3,610 patients. ER, PR, HER2 from the TACT trial and Tau protein expression was determined by immunohistochemistry on duplicate TMAs. Two parallel scoring systems were generated for Tau expression ('dichotomised' vs. 'combined' score). The positivity rate of Tau expression was 50 % in the trial population (n = 2,483). Tau expression correlated positively with ER (p < 0.001) and PR status (p < 0.001); but negatively with histological grade (p < 0.001) and HER2 status (p < 0.001). Analyses with either scoring systems for Tau expression demonstrated no significant interaction between Tau expression and efficacy of docetaxel. Contrary to the hypothesis that taxane benefit would be enriched in Tau negative/low patients, the only groups with a suggestion of a reduced event rate in the taxane group were the HER2-positive, Tau positive subgroups. Tau expression was seen to be a prognostic factor on univariate analysis associated with an improved DFS, independent of the treatment group (p < 0.001). It had no prognostic value in ER-negative tumours and the weak prognostic effect of Tau in ER-positive tumours (p = 0.02) diminished, when considering ER as an ordinal variable. On multivariable analyses, Tau had no prognostic value in either group. In addition, no significant interaction between Tau expression and benefit from docetaxel in patients within the PR-positive and negative subsets was seen. This is now the second large adjuvant study, and the first with quantitative analysis of ER and Tau expression, failing to show an association between Tau and taxane benefit with limited utility as a prognostic marker for Tau in ER-positive early breast cancer patients.

The prognostic and predictive impact of genomic grade index (GGI) versus central grade or molecular class in intermediate-risk breast cancer (BC): Results from the EC-Doc trial.

1092 Background: Potential markers for adjuvant taxane-based chemotherapy (CTx) in early, intermediate-risk BC include histologic grade (HG), Ki-67, Genomic Grade (GG) or molecular classification. The randomized EC-Doc trial demonstrated improvements in DFS and OS for EC-Doc vs. FEC in patients with 1-3 positive LN. Methods: Centrally assessed protein expression data by IHC, histology/HG (n=772) and GG (n=476) were obtained. Luminal A/B classes were defined as: ER/PR+/KI-67&lt;20/&gt;20% and/or HER2+. Correlations/concordance of these factors were estimated; impact on DFS and value for predicting taxane-based CTx benefit was assessed. Results: Low, equivocal and high GG (GG-1/-EQ/-3) categories were observed among 54 (11%); 60 (13%); 358 patients (76%) and associated with decreasing 5-yr-DFS rates of 100%, 92% and 82% (p &lt; 0.001).There is only 60% concordance between local (L)/central(C) HG assessments and 63% between GG and C-HG. 37.7% of GG-3 tumors were L- HG3 vs. 72% C-HG3; 79% of C-HG2 and 83% of L-HG2 tumors were re-classified (56-71% to GGI3). Only 5.6-6% of GG1 were HG1 by L/C-HG respectively.GG was prognostic only in L-HG subgroups.In univariate subgroup analyses, EC-Doc was significantly superior to FEC: C-G3 (HR=0.58, 0.39-0.93), high Ki-67 (HR=0.55, 0.32E0.92) and GG-3 (HR=0.58, 0.34-0.99) subgroups. In multivariate analyses of HR+ disease (including age, therapy, GGI category, tumor size, LN status, central/local HG, Ki-67, HER2), either C-HG3 / high Ki-67 (as dichotomous variables) or C-HG3 / GGI (as continuous variable) were identified as independent prognostic factors.In interaction analysis, only C-HG, luminal A subtype and interaction of luminal-B/therapy were significant. If local HG was included instead of C-HG, only GG was as independent prognostic factor. Conclusions: These data support GGI as independent prognostic factor in early HR+ BC and as predictive marker regarding taxane benefit by univariate analysis. There is heterogeneity between L/C-HG and GGI. C-HG and Ki-67 assessment appear similarly informative. A predictive effect regarding benefit of taxane-containing CTx was seen in the IHC-luminal B subtype.

Taxane benefit in breast cancer—a role for grade and chromosomal stability

Chromosomal instability, which is a characteristic of many human cancers, contributes to intratumour heterogeneity and has been functionally implicated in resistance to taxane therapy in tumour models. However, defining the status of tumour chromosomal instability in a given tumour to test this hypothesis remains challenging. Measurements of numerical and structural chromosomal heterogeneity demonstrate that histological grade correlates with chromosomal instability in oestrogen receptor (ER)-positive breast cancer. Using data on adjuvant taxane therapy in women with breast cancer, we propose that patients with low-grade ER-positive tumours, which are thought to be chromosomally stable, might derive unexpected benefit from taxane therapy. We discuss the implications of the relationships between tumour grade, chromosomal instability and intratumour heterogeneity, the development of high-throughput methods to define tumour chromosomal instability and the potential use of chromosomal instability to tailor therapy.

Abstract P6-07-15: The effect of taxanes in ER+ early breast cancer is likely to be mitigated by chromosomal instability.

Abstract Background: Mechanisms of tumour sensitivity to microtubule-stabilizing (MTS) agents, such as taxanes, are still a matter of debate. Through an RNA interference screen for regulators of taxane resistance, our group identified a number of genes which initiated taxane resistance and Chromosomal INstability (CIN) (1) when silenced, suggesting that the cellular mechanisms that monitor faithful chromosome segregation may also impact upon taxane sensitivity. Consistent with this hypothesis, we previously reported in a small clinical trial cohort of ovarian cancers that CIN tumours (defined by overexpression of the CIN70 signature) appeared to be relatively resistant to paclitaxel in vivo (2). We have observed that repression of a subset of the CIN70 signature occurs in diploid cancer cells following paclitaxel exposure, contributing to cell death. Conversely, less efficient repression of these CIN70 genes occurs in CIN cells following paclitaxel exposure. Overexpression of the CIN70 signature is associated with poor clinical outcome and chromosomal instability is significantly correlated with high tumour grade in ER positive disease. We hypothesised that in ER+ tumours the effect of taxanes should decrease with tumour grade and relative chromosomal instability (3). We assessed this hypothesis by analysing the differences in the published taxane effect in the EBCTCG Chemotherapy overview (4) according to tumour grade. Methods: Annual event rate ratios and 95% CIs were calculated from data on over 20,000 early breast cancer patients treated with chemotherapy (4). P-values for trend in taxane effect were calculated across 3 tumour grade categories or for heterogeneity between 2 categories. Results: The table shows annual event rate ratios (CIs) for grade categories, for taxane-plus-anthracycline-based regimen versus the same, or more (&amp;lt; doubled or ∼doubled) non-taxane cytotoxic chemotherapy. Significantly different taxane effects were observed across categories of tumour grade. For both endpoints taxane benefit increased with lower tumour grade, there was a smaller effect in high grade tumours and no evidence the treatment benefit decreased with follow up time. Conclusions: These results support the assessment of CIN in ER+ breast cancer to optimize treatment stratification and clinical trial design when using microtubule-stabilizing agents. Significant benefit from adjuvant taxanes appeared to be restricted to the lower risk, low and intermediate grade ER positive cohort. Differences in recurrence and survival in this low risk cohort with the use of taxanes would be detected in a worldwide meta-analysis and could easily be missed in individual trials.

Epithelial Cell Dissemination and Readhesion: Analysis of Factors Contributing to Metastasis Formation in Breast Cancer

Although considerable progress has been achieved in breast cancer diagnosis and treatment, the live-saving effect of mammography has hardly been measurable and the benefit of taxanes regarded as highly active is still a matter of debate, possibly because treatment effects have hitherto been mainly determined from the solid part of the tumor, due to lack of measurability of the systemic part of the disease. Here, we have quantified the influence on the systemic disease, cells mobilized from the solid tumor. Increased numbers of circulating epithelial cells were observed in screened individuals and still higher numbers in breast cancer patients with repeated mammograms as compared to mammogram naïve individuals. Taxanes as part of the subsequent systemic treatment led to mobilization of tumor suspect cells in up to 78% cases and the majority of relapses have occurred in these patients. Surgery-induced activation of disseminated cells may additionally contribute to metastasis formation.

Docetaxel-containing adjuvant chemotherapy in patients with early stage breast cancer. Consistency of effect independent of nodal and biomarker status: a meta-analysis of 14 randomized clinical trials

The benefit of taxanes in the adjuvant setting for node-negative (N0) early breast cancer (EBC) has not yet been established. We conducted a meta-analysis of randomized adjuvant trials comparing docetaxel-containing versus non-taxane-containing regimens. The purpose of this study was to determine whether the incorporation of docetaxel improves disease-free survival (DFS) and overall survival (OS) in early stage breast cancer. Studies were retrieved by searching major databases and the proceedings of leading breast cancer conferences. We extracted hazard ratios (HRs) and 95% confidence intervals (CIs) for DFS and OS and obtained pooled estimates using an inverse-variance model. Fourteen randomized phase III studies were included (25,067 patients). The pooled HR estimate was 0.84 (95% CI 0.78-0.89; P < 0.001) favoring docetaxel for DFS and 0.86 (0.78-0.94; P < 0.001) for OS. In N0 patients (4,274 patients), the pooled HR estimate for DFS was 0.86 (0.73-1.00; P = 0.05). The HR for OS was equal to 1 (0.75-1.34). The improvement in DFS with docetaxel-containing regimens was observed across all subgroups (age, under or over 50; number of involved nodes; hormone receptor or HER2 status (including triple negative status), or administration schedule (sequential or concomitant). The addition of docetaxel to a non-taxane-containing regimen improves DFS and OS in high risk EBC patients. The benefit in DFS was seen across all subgroups regardless of nodal status, age, hormone receptor or HER2 status (including triple negative status), or administration schedule.