Jens Huober

PIK3CA mutations are associated with lower rates of pathologic complete response to anti-human epidermal growth factor receptor 2 (her2) therapy in primary HER2-overexpressing breast cancer.

PURPOSEnPhosphatidylinositol 3-kinase (PI3K)/AKT pathway aberrations are common in breast cancer, with mutations in PIK3CA being the most common. This study investigated the association between PIK3CA genotype and pathologic complete response (pCR) rates in human epidermal growth factor receptor 2 (HER2)-positive breast cancer treated with either dual or single anti-HER2 treatment in addition to neoadjuvant chemotherapy.nnnPATIENTS AND METHODSnPIK3CA mutations in 504 tumor samples from participants in the neoadjuvant GeparQuattro, GeparQuinto, and GeparSixto studies were evaluated. All HER2-positive patients received either trastuzumab or lapatinib or the combination plus anthracycline-taxane chemotherapy. PIK3CA mutations were evaluated in formalin-fixed, paraffin-embedded tissues from core biopsies with a tumor cell content of ≥ 20% by using classical Sanger sequencing of exon 9 and exon 20.nnnRESULTSnOverall, 21.4% of the patients harbored a PIK3CA mutation. Detection of a PIK3CA mutation was significantly associated with a lower pCR rate (19.4% with PIK3CA mutation v 32.8% with PIK3CA wild-type; odds ratio [OR], 0.49; 95% CI, 0.29 to 0.83; P = .008). In the 291 hormone receptor (HR) -positive tumors, pCR rate was 11.3% with a PIK3CA mutation compared with 27.5% with PIK3CA wild-type (OR, 0.34; 95% CI, 0.15 to 0.78; P = .011). In 213 patients with HR-negative tumors, pCR rate was 30.4% with PIK3CA mutation and 40.1% without (OR, 0.65; 95% CI, 0.32 to 1.32; P = .233; interaction test P = .292). In multivariable analysis, HR status and PIK3CA status provided independent predictive information. In patients with PIK3CA mutation, the pCR rates were 16%, 24.3%, and 17.4% with lapatinib, trastuzumab, and the combination, respectively (P = .654) and in the wild-type group, they were 18.2%, 33.%, and 37.1%, respectively (P = .017). Disease-free survival and overall survival were not statistically significantly different between patients with mutant and wild-type PIK3CA.nnnCONCLUSIONnHER2-positive breast carcinomas with a PIK3CA mutation are less likely to achieve a pCR after neoadjuvant anthracycline-taxane-based chemotherapy plus anti-HER2 treatment, even if a dual anti-HER2 treatment is given.

Ki67 levels as predictive and prognostic parameters in pretherapeutic breast cancer core biopsies: a translational investigation in the neoadjuvant GeparTrio trial

BACKGROUNDnThe proliferation marker Ki67 has been suggested as a promising cancer biomarker. As Ki67 needs an exact quantification, this marker is a prototype of a new generation of tissue-based biomarkers. In this study, we have systematically evaluated different cut points for Ki67 using three different clinical end points in a large neoadjuvant study cohort.nnnPATIENTS AND METHODSnWe have evaluated pretherapeutic Ki67 levels by immunohistochemistry in 1166 breast cancer core biopsies from the neoadjuvant GeparTrio trial. We used the standardized cutoff-finder algorithm for three end points [response to neoadjuvant chemotherapy (pCR), disease-free (DFS) and overall-survival (OS)]. The analyses were stratified for hormone receptor (HR) and HER2 status by molecular subtype radar diagrams (MSRDs).nnnRESULTSnA wide range of Ki67 cut points between 3%-94% (for pCR), 6%-46% (for DFS) and 4%-58% (for OS) were significant. The three groups of Ki67 ≤ 15% versus 15.1%-35% versus >35% had pCR-rates of 4.2%, 12.8%, and 29.0% (P < 0.0005), this effect was also present in six of eight molecular subtypes. In MSRD, Ki67 was significantly linked to prognosis in uni- and multivariate analysis in the complete cohort and in HR-positive, but not triple-negative tumors.nnnCONCLUSIONSnKi67 is a significant predictive and prognostic marker over a wide range of cut points suggesting that data-derived cut point optimization might not be possible. Ki67 could be used as a continuous marker; in addition, the scientific community could define standardized cut points for Ki67. Our analysis explains the variability observed for Ki67 cut points in previous studies; however, this should not be seen as weakness, but as strength of this marker. MSRDs are an easy new approach for visualization of biomarker effects on outcome across molecular subtypes in breast cancer. The experience with Ki67 could provide important information regarding the development and implementation of other quantitative biomarkers.

Ki67 measured after neoadjuvant chemotherapy for primary breast cancer

Purpose: The value of Ki67 measured on residual disease after neoadjuvant chemotherapy is not sufficiently described. Experimental Design: Participants of the GeparTrio study with primary breast cancer randomly received neoadjuvant response-guided [8 cycles TAC (docetaxel/doxorubicin/cyclophosphamide) in responding and TAC-NX (vinorelbine/capecitabine) in nonresponding patients] or conventional (6 cycles TAC) chemotherapy according to interim response assessment. Ki-67 levels were centrally measured immunohistochemically after neoadjuvant treatment if tumor tissue was available. Here, we analyze 1,151 patients having a pathologic complete response (pCR; n, 484), or residual disease with low (0–15%), intermediate (15.1–35%), or high (35.1–100%) posttreatment Ki67 levels in 488, 77, and 102 patients, respectively. Results: Patients with high posttreatment Ki67 levels showed higher risk for disease relapse (P < 0.0001) and death (P < 0.0001) compared with patients with low or intermediate Ki67 levels. Patients with low Ki67 levels showed a comparable outcome to patients with a pCR (P = 0.211 for disease-free and P = 0.779 for overall survival). Posttreatment Ki67 levels provided more prognostic information than pretreatment Ki67 levels or changes of Ki67 from pre- to posttreatment. Information on pCR plus posttreatment Ki67 levels surmount the prognostic information of pCR alone in hormone–receptor-positive disease [hazard ratios (HR), 1.82–5.88] but not in hormone–receptor-negative disease (HR: 0.61–1.73). Patients with conventional and response-guided treatment did not show a different distribution of posttreatment Ki67 (P = 0.965). Conclusions: Posttreatment Ki67 levels provide prognostic information for patients with hormone–receptor-positive breast cancer and residual disease after neoadjuvant chemotherapy. Levels were not prognostic for outcome after response-guided chemotherapy. High posttreatment Ki67 indicates the need for innovative postneoadjuvant treatments. Clin Cancer Res; 19(16); 4521–31. ©2013 AACR.

Neoadjuvant bevacizumab and anthracycline–taxane-based chemotherapy in 678 triple-negative primary breast cancers; results from the geparquinto study (GBG 44)

BACKGROUNDnWe evaluated the pathological complete response (pCR) rate after neoadjuvant epirubicin, (E) cyclophosphamide (C) and docetaxel containing chemotherapy with and without the addition of bevacizumab in patients with triple-negative breast cancer (TNBC).nnnPATIENTS AND METHODSnPatients with untreated cT1c-4d TNBC represented a stratified subset of the 1948 participants of the HER2-negative part of the GeparQuinto trial. Patients were randomized to receive four cycles EC (90/600 mg/m(2); q3w) followed by four cycles docetaxel (100 mg/m(2); q3w) each with or without bevacizumab (15 mg/kg; q3w) added to chemotherapy.nnnRESULTSnTNBC patients were randomized to chemotherapy without (n = 340) or with bevacizumab (n = 323). pCR (ypT0 ypN0, primary end point) rates were 27.9% without and 39.3% with bevacizumab (P = 0.003). According to other pCR definitions, the addition of bevacizumab increased the pCR rate from 30.9% to 41.8% (ypT0 ypN0/+; P = 0.004), 36.2% to 46.4% (ypT0/is ypN0/+; P = 0.009) and 32.9% to 43.3% (ypT0/is ypN0; P = 0.007). Bevacizumab treatment [OR 1.73, 95% confidence interval (CI) 1.23-2.42; P = 0.002], lower tumor stage (OR 2.38, 95% CI 1.24-4.54; P = 0.009) and grade 3 tumors (OR 1.68, 95% CI 1.14-2.48; P = 0.009) were confirmed as independent predictors of higher pCR in multivariate logistic regression analysis.nnnCONCLUSIONSnThe addition of bevacizumab to chemotherapy in TNBC significantly increases pCR rates.

Influence of zoledronic acid on disseminated tumor cells (DTC) in primary breast cancer patients.

CTRC-AACR San Antonio Breast Cancer Symposium: 2008 AbstractsnnAbstract #2048 nnBackground: The presence of disseminated tumor cells (DTC) in the bone marrow is associated with an increased risk for subsequent bone metastases. Bisphosphonates reduce the occurence of bone metastases in patients (pts) with primary breast cancer (BC) with DTC. The aim of this trial was to evaluate the effect of adjuvant zoledronic acid (ZOL) on DTC in the bone marrow and the Patients and methods: Eligibilty criteria for this prospective, randomized multicenter trial were primary BC pts (pT1-4, N1-2, M0) with positive bone marrow status as determined by a standardized immunocytochemistry staining procedure. Ninety-eight pts were enrolled between April 2002 and January 2006. Randomization and medication had to be started within 28 days of primary surgery. Consenting pts were randomized to the treatment arm (ZOL 4mg i.v. q 4 weekly) or control arm. During the study, all pts received adjuvant treatment in the form of chemotherapy ± hormonal therapy or hormonal therapy alone. Bone marrow aspirations were performed to analyze the presence of DTC at surgery (baseline) and 12 months later. Efficacy and tolerability of intravenous ZOL in pts with primary Result: Bone marrow status was available for 76 patients both at baseline and 12 months after surgery. At baseline a median of 2.0 / range 1-6 (mean 2.1±1.1) DTC were detected in the ZOL group and a median of 2.0 / range 1-35 (mean 2.9±5.5) DTC in the control group. In both groups the number of detected tumor cells decreased during the 12 months follow-up with 0.5±0.8 (median 0.0; 0-2) DTC in the ZOL group and 0.9±0.8 (median 1.0; 0-2) DTC in the control group. By ANCOVA analysis a trend was seen towards a reduction of the number of DTC in the ZOL group compared with the control group (p=0.066). In addition, bone marrow-positive pts treated with ZOL were more likely to become bone marrow negative after 12 months (66.7% versus 35.1%, (p=0.009) compared to the control group. Most frequently reported AEs were musculoskeletal,arthralgia and myalgia in Conclusions: In this first prospective, randomized, multicenter trial we were able to show, that both treatment groups have a reduction in the number of DTC after 12 months as compared to baseline. There is a tendency to more reduction of DTC in the ZOL group. More pts under ZOL achieved a change from positive to negative bone marrow status than controls (p=0.009). Treatment with ZOL was safe and well tolerated.nnCitation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2048.

HER2 and ESR1 mRNA expression levels and response to neoadjuvant trastuzumab plus chemotherapy in patients with primary breast cancer.

IntroductionRecent data suggest that benefit from trastuzumab and chemotherapy might be related to expression of HER2 and estrogen receptor (ESR1). Therefore, we investigated HER2 and ESR1 mRNA levels in core biopsies of HER2-positive breast carcinomas from patients treated within the neoadjuvant GeparQuattro trial.MethodsHER2 levels were centrally analyzed by immunohistochemistry (IHC), silver in situ hybridization (SISH) and qRT-PCR in 217 pretherapeutic formalin-fixed, paraffin-embedded (FFPE) core biopsies. All tumors had been HER2-positive by local pathology and had been treated with neoadjuvant trastuzumab/ chemotherapy in GeparQuattro.ResultsOnly 73% of the tumors (158 of 217) were centrally HER2-positive (cHER2-positive) by IHC/SISH, with cHER2-positive tumors showing a significantly higher pCR rate (46.8% vs. 20.3%, P <0.0005). HER2 status by qRT-PCR showed a concordance of 88.5% with the central IHC/SISH status, with a low pCR rate in those tumors that were HER2-negative by mRNA analysis (21.1% vs. 49.6%, P <0.0005). The level of HER2 mRNA expression was linked to response rate in ESR1-positive tumors, but not in ESR1-negative tumors. HER2 mRNA expression was significantly associated with pCR in the HER2-positive/ESR1-positive tumors (P = 0.004), but not in HER2-positive/ESR1-negative tumors.ConclusionsOnly patients with cHER2-positive tumors - irrespective of the method used - have an increased pCR rate with trastuzumab plus chemotherapy. In patients with cHER2-negative tumors the pCR rate is comparable to the pCR rate in the non-trastuzumab treated HER-negative population. Response to trastuzumab is correlated to HER2 mRNA levels only in ESR1-positive tumors. This study adds further evidence to the different biology of both subsets within the HER2-positive group.Introduction The human epidermal growth factor receptor 2 (HER2) is the prototype of a predictive biomarker for targeted treatment [1–8]. International initiatives have established the combination of immunohistochemistry (IHC) and in situ hybridization as the current gold standard [9, 10]. As an additional approach determination of HER2 mRNA expression is technically feasible in formalin-fixed paraffin-embedded (FFPE) tissue [11–13]. Crosstalk between the estrogen receptor (ER) and the HER2 pathway has been suggested based on cell culture and animal models [14]. Consequently, the 2011 St Gallen panel has pointed out that HER2-positive tumors should be divided into two groups based on expression of the ER [15].A retrospective analysis of the National Surgical Adjuvant Breast and Bowel Project (NSABP) B31 study has suggested that mRNA levels of HER2 and ESR1 might be relevant for the degree of benefit from adjuvant trastuzumab. By subpopulation treatment effect pattern plot (STEPP) analysis in ER-positive tumors, benefit from trastuzumab was shown to be restricted to those with higher levels of HER2 mRNA (S Paik, personal communication, results summarized in [15]).In our study we evaluated this hypothesis in the neoadjuvant setting in a cohort of 217 patients from the neoadjuvant GeparQuattro trial [5]. All patients had been HER2- positive by local pathology assessment and had received 24 to 36 weeks of neoadjuvant trastuzumab plus an anthracycline/taxane-based chemotherapy. For central evaluation we used three different methods, HER2 IHC, and HER2 silver in situ hybridization (SISH), as well as measurement of HER2 mRNA by quantitative real-time (qRT)-PCR [11].The primary objective of this analysis was to investigate if pathological complete response (pCR) rate in HER2-positive breast cancer would depend on the level of HER2 mRNA expression, with a separate analysis for HR-positive and -negative tumors. Central evaluation of the HER2 status showed that 27% of the tumors with HER2 overexpression by local pathology were HER2-negative. This enabled us to compare response rates in patients with HER2-positive and -negative tumors as a secondary objective.

Influence of zoledronic acid on disseminated tumor cells in bone marrow and survival: results of a prospective clinical trial

BackgroundThe presence of disseminated tumor cells (DTC) in bone marrow (BM) of breast cancer patients is associated with reduced clinical outcome. Bisphosphonate treatment was shown to eradicate DTC from BM in several studies. This controlled randomized open-label multi-center study aimed to investigate the influence of zoledronic acid (ZOL) on DTC and survival of breast cancer patients (Clinical Trial Registration Number: NCT00172068).MethodsPatients with primary breast cancer and DTC-positive bone marrow were randomized to treatment with ZOL plus adjuvant systemic therapy (n = 40) or adjuvant systemic therapy alone (n = 46) between 03/2002 and 12/2004. DTC were identified by immunocytochemistry using the pancytokeratin antibody A45B/B3 and by cytomorphology. The change in DTC numbers at 12 months and 24 months versus baseline, as well as patient outcomes were evaluated.Results86 patients could be included into survival analysis (median follow-up: 88 months, range: 8–108 mths). Patients in the control group were more likely to die during follow-up than those in the ZOL-group (11% vs. 2%, p = 0.106). 15% of patients in the control group presented with relapse whereas only 8% of ZOL group patients developed metastatic or recurrent disease during follow-up (p = 0.205). At 24 months, 16% of patients from the control group were still DTC positive, whereas all patients treated with ZOL became DTC negative (p = 0.032). Patients presenting with persistent DTC 12 months after diagnosis had significantly shorter overall survival (p = 0.011).ConclusionsBisphosphonate therapy contributes to eradication of disseminated tumor cells. The positive influence of bisphosphonates on survival in the adjuvant setting may be due to their effects on DTC.Trial registrationClinicalTrials.gov Identifier: NCT00172068 [Zoledronic Acid in the Treatment of Breast Cancer With Minimal Residual Disease in the Bone Marrow (MRD-1)].

Surgical Outcome after Neoadjuvant Chemotherapy and Bevacizumab: Results from the GeparQuinto Study (GBG 44)

AbstractPurposenBevacizumab, a humanized monoclonal antibody against vascular endothelial growth factor, has shown increased pathological complete response rates when added to neoadjuvant chemotherapy. In various cancer types, bevacizumab treatment was accompanied by an increased risk of bleedings and other surgical complications. We assessed associated surgical complications.MethodsIn the GeparQuinto trial, 1,948 patients were randomized to receive four cycles epirubicin/cyclophosphamide (EC, 90/600xa0mg/m2 q3w) followed by four cycles docetaxel (D, 100xa0mg/m2 q3w) each with (ECB-DB) or without (EC-D) bevacizumab (B, 15xa0mg/kg q3w) concurrent with chemotherapy. Surgery had to be performed not earlier than 28xa0days after the last bevacizumab infusion, but within days 21 and 35 after the last chemotherapy.ResultsIn 743 (38.1xa0%) patients, a surgical complication (bleedings, hematomas, necrosis, wound infections, abscess) was documented prospectively. Baseline characteristics of the patients were well balanced between both arms. The breast-conserving surgery (BCS) rate (Nxa0=xa0502) was 69.1xa0% (EC-D) and 71.9xa0% (ECB-DB; pxa0=xa00.464). The first surgical procedure was performed at a median of 29 (EC-D) and 34xa0days (ECB-DB) after last chemotherapy with or without bevacizumab infusion (pxa0<xa00.001). Surgical complications were documented in 38 (10.9xa0%; EC-D) and 59 (15.0xa0%; ECB-DB) patients (pxa0=xa00.103). Surgical complications were significantly higher after ECD-DB only in patients treated with BCS (Nxa0=xa053; pxa0=xa00.029) or in those requiring repeat surgery in order achieve clear margins (Nxa0=xa023; pxa0=xa00.037) compared to the EC-D group.ConclusionsnAddition of bevacizumab to neoadjuvant chemotherapy might be associated with an increased risk for surgical complications in patients treated with BCS or after repeated surgeries.

Abstract LB-63: Relationship between tumor biomarkers (BM) and efficacy in EMILIA, a phase III study of trastuzumab emtansine (T-DM1) in HER2-positive metastatic breast cancer (MBC).

Background: The antibody-drug conjugate T-DM1 retains the mechanisms of action of trastuzumab, including HER2 targeting and interruption of HER2 signaling, and provides a means of delivering the cytotoxic agent DM1 directly to HER2-positive tumors. In the EMILIA study, T-DM1 demonstrated a statistically significant progression-free and overall survival (PFS, OS) benefit with less toxicity vs capecitabine plus lapatinib (XL) in patients (pts) with previously treated HER2-positive MBC. Activating mutations of PIK3CA may lead to resistance to currently available HER2-directed therapies. The relationship between treatment efficacy and tumor HER2 mRNA expression or PIK3CA mutation status was examined in pts from EMILIA. Methods: Tumor tissue collected for HER2 testing was also used for HER2 mRNA analysis by qRT-PCR and for PIK3CA assessment (with additional consent), using a PIK3CA Mutation Detection Kit. PFS and OS were analyzed for each BM subgroup using the Kaplan-Meier method and a Cox regression model. Results: Median mRNA concentration ratios and PIK3CA mutation frequency were similar across treatment arms and consistent with data previously reported. T-DM1 demonstrated superior PFS and OS vs XL in all BM subgroups. The hazard ratio of OS was less for pts with high (>median) vs low tumor HER2 mRNA levels. For XL-treated pts, PIK3CA mutations were associated with shorter median PFS and OS; PIK3CA mutations did not significantly affect T-DM1 treatment outcomes. Conclusions: Pts in all BM subgroups analyzed to date had longer PFS and OS with T-DM1 vs XL. Pts with tumors expressing high HER2 mRNA levels derived even greater OS benefit from T-DM1. XL-treated pts with PIK3CA mutations had worse outcomes than those with wild type PIK3CA. T-DM1-treated pts with PIK3CA mutations had a similar treatment benefit as those without, suggesting that the unique mechanism of action of T-DM1 may overcome PIK3CA mutation resistance. Citation Format: Jose Baselga, Sunil Verma, Jungsil Ro, Jens Huober, Ellie Guardino, Liang Fang, Steven Olsen, Gail Lewis Phillips, Sanne de Haas, Mark Pegram. Relationship between tumor biomarkers (BM) and efficacy in EMILIA, a phase III study of trastuzumab emtansine (T-DM1) in HER2-positive metastatic breast cancer (MBC). [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-63. doi:10.1158/1538-7445.AM2013-LB-63