Abstract P1-14-11: nab-paclitaxel at a dose of 125 mg/m2 weekly is more efficacious but less toxic than at 150 mg/m2. Results from the neoadjuvant randomized GeparSepto study (GBG 69)

Background: We previously reported that nab-paclitaxel (nP) increases the pathological complete response (pCR, ypT0 ypN0) rate when it replaces solvent-based paclitaxel (P) as part of a sequential taxane followed by epirubicin/cyclophosphamide (EC) neoadjuvant chemotherapy for patients with early breast cancer (Untch et al. SABCS 2014). Here, we report efficacy and safety of patients being treated either with 150 mg/m2 nab-paclitaxel (nP150) before an amendment or with 125 mg/m2 nab-paclitaxel (nP125) thereafter in comparison to solvent-formulated paclitaxel at 80 mg/m2 (P80).

Methods: In the GeparSepto study (NCT01583426), 1207 patients were randomized to either nP150 or P80 q1w for 12 weeks followed by 4 cycles of conventionally dosed EC (E: 90mg/m2; C: 600 mg/m2) q3w. The primary objective of the study was to compare the pCR rate (pCR, ypT0 ypN0). Patients with untreated, histologically confirmed uni- or bilateral, cT2- cT4d carcinoma, and no clinically relevant cardiovascular and other co-morbidities were included. Patients with HER2+ tumors received trastuzumab (loading dose 8mg/kg; 6 mg/kg) plus pertuzumab (loading dose 840 mg; 420 mg) q3w concomitantly to all chemotherapy cycles. After a safety analysis showed a higher rate of dose reductions and treatment discontinuations with nP150 compared to P80, weekly dose of nP was reduced to 125 mg/m2.

Results: nP was given for the majority of cycles at a dose of 150 mg/m2 to 179 patients and at a dose of 125 mg/m2 to 426 patients. Treatment characteristics were fairly balanced between these two sequential cohorts as well as compared to 601 patients receiving P80 except for HER2 status (HER2-positive: nP150 22%, nP125 37% and P80 33%) and Ki67 (<20%: nP150 60%, nP125 73% and P80 69%). Taxane treatment was discontinued in 16% (nP150), 11% (nP125) and 6% (P80) of patients, respectively. Median dose per cycle (based on relative total dose intensity (RTDI)) was 129 mg/m2 with nP150, 119 mg/m2 with nP125 and 78 mg/m2 with P80, respectively. Peripheral sensory neuropathy (PNP) grade 3/4 (NCI-CTCAE v4.0) was observed in 15% with nP150, 8% with nP125 and 3% with P80, respectively. pCR was 32% with nP150, 41% with nP125 and 29% with P80 in all patients and 46% with nP150, 49% with nP125 and 26% with P80 in 277 patients with triple-negative breast cancer, respectively.

Conclusions: Risk-benefit ratio of nP125 was improved over nP150 with better drug adherence and RTDI, lower frequency of PNP but a higher pCR rate. It should therefore be considered as the preferred schedule when nP is used as neoadjuvant treatment for primary breast cancer.

The trial was financially supported by Celgene and Roche.

Citation Format: von Minckwitz G, Untch M, Jakisch C, Schneeweiss A, Conrad B, Aktas B, Denkert C, Eidtmann H, Weibringhaus H, Kümmel S, Hilfrich J, Warm M, Paepke S, Just M, Hanusch C, Hackmann J, Blohmer J-U, Clemens M, Costa SD, Gerber B, Nekljudova V, Loibl S. nab-paclitaxel at a dose of 125 mg/m2 weekly is more efficacious but less toxic than at 150 mg/m2. Results from the neoadjuvant randomized GeparSepto study (GBG 69). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-14-11.

Survival after adding capecitabine and trastuzumab to neoadjuvant anthracycline-taxane-based chemotherapy for primary breast cancer (GBG 40--GeparQuattro)

BACKGROUND

The GeparQuattro study showed that adding capecitabine or prolonging the duration of anthracycline-taxane-based neoadjuvant chemotherapy from 24 to 36 weeks did not increase pathological complete response (pCR) rates. Trastuzumab-treated patients with HER2-positive disease showed a higher pCR rate than patients with HER2-negative disease treated with chemotherapy alone. We here present disease-free (DFS) and overall survival (OS) analyses.

PATIENTS AND METHODS

Patients (n = 1495) with cT ≥ 3 tumors, or negative hormone-receptor status, or positive hormone-receptor and clinically node-positive disease received four times epirubicin/cyclophosphamide and were thereafter randomly assigned to four times docetaxel (Taxotere), or four times docetaxel/capecitabine over 24 weeks, or four times docetaxel followed by capecitabine over 36 weeks. Patients with HER2-positive tumors received 1 year of trastuzumab, starting with the first chemotherapy cycle. Follow-up was available for a median of 5.4 years.

RESULTS

Outcome was not improved for patients receiving capecitabine (HR 0.92; P = 0.463 for DFS and HR 93; P = 0.618 for OS) as well as for patients receiving 36 weeks of chemotherapy (HR 0.97; P = 0.818 for DFS and HR 0.97; P = 0.825 for OS). Trastuzumab-treated patients with HER2-positive disease showed similar DFS (P = 0.305) but a significantly better adjusted OS (P = 0.040) when compared with patients with HER2-negative disease treated with chemotherapy alone. Recorded long-term cardiac toxicity was low.

CONCLUSIONS

Long-term results, similar to the results of pCR, do not support the use of capecitabine in the neoadjuvant setting in addition to an anthracycline-taxane-based chemotherapy. However, the results support previous data showing a benefit of trastuzumab as predicted by higher pCR rates.

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

BACKGROUND

The 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.

PATIENTS AND METHODS

We 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).

RESULTS

A 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.

CONCLUSIONS

Ki67 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.

Abstract OT3-3-11: A RANDOMIZED PHASE III TRIAL COMPARING NANOPARTICLE-BASED PACLITAXEL WITH SOLVENT-BASED PACLITAXEL AS PART OF NEOADJUVANT CHEMOTHERAPY FOR PATIENTS WITH EARLY BREAST CANCER (GeparSepto) GBG 69

Background: Anthracycline/taxane based regimen are standard of care for neoadjuvant therapy in breast cancer. Recent data from the neo-Tango study suggest that a reverse sequence of taxane followed by the anthracycline can achieve higher pCR rates. Solvent-based taxanes (paclitaxel, docetaxel) cause severe toxicities most likely by the solvents such as cremophor. Nab-paclitaxel is a solvent-free formulation of paclitaxel encapsulated in albumin. It is believed that nab-Paclitaxel compared to solvent based paclitaxel followed by conventional dosed EC might further improve the pCR rate in breast cancer patients receiving neoadjuvant treatment. Previous studies have shown that dual anti-HER blockade is superior to trastuzumab alone resulting in an increase of pCR rate by 20%.

Patients and Methods: The GeparSepto trial, a neoadjuvant, randomized phase III study, planned to include 1200 pts, randomized to nab-paclitaxel versus conventional, solvent based paclitaxel given weekly for 12 weeks followed in both arms by 4 cylces conventionally dosed EC. The primary objective is to compare the rate of pCR (ypT0 + ypN0). Further objectives are to compare the pCR rate in predefined subgroups, pCR by other definition, the clinical response rate and the rate of breast conserving surgery after chemotherapy in the two different treatment arms.

Women with untreated, histologically confirmed uni- or bilateral, cT2- cT4d carcinoma, and no clinically relevant cardiovascular and other co-morbidities are randomized to receive either paclitaxel (80mg/m2) or nab-paclitaxel (150 mg/ m2) day 1, 8, 15, q d 22 for 4 cycles followed by conventional EC (E (90mg/m2)+C (600 mg/m2)) on day 1 q day 22 for 4 cycles. HER2 positive pts receive trastuzumab (loading dose 8mg/kg followed by 6 mg/kg) and pertuzumab (loading dose 840 mg followed by 420 mg) q3w concomitantly to the chemotherapy. Biomaterial including FFPE form core biopsy, serum, plasma, full blood is collected before randomization, after the 12 cycles for (nab−) paclitaxel therapy and after the 4 cycles of EC before surgery. The HER2, estrogen receptor, progesterone receptor, Ki67 and SPARC status will be centrally tested by immunohistochemistry prior to randomization for stratification. A broad translational program is planned. It has been assumed that solvent based taxane will achieve an overall pCR rate of 33% to be increased using nab-paclitaxel to 41%, corresponding to an odds ratio of 1.41. If 596 patients are enrolled into each arm, a χ2-test will have an 80% power with a 2-sided significance level α=0.05 to show the superiority of nab-paclitaxel. Closed test procedure will be used to test for non-inferiority of nab-paclitaxel first.

The trial is registered under NCT01583426. It is financially supported by Roche and Celgene.

Results: The centres have been initiated after approval by ethics committee and authorities.

First patient in will be this months. It is planned to recruit 18 months in 100 sites in Germany.

Conclusion: Geparsepto will investigate the efficacy of neoadjuvant nab-paclitaxel compared to solvent based paclitaxel given weekly and the dual blockade with Trastuzumab and Pertuzumab in HER 2 positive BC.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr OT3-3-11.

Abstract PD06-01: Automated computational Ki67 scoring in the GeparTrio breast cancer study cohort

Background: Scoring proliferation through Ki67-immunohistochemistry is an important component in predicting therapy response to chemotherapy in breast cancer patients. Therefore, an accurate and standardized Ki67-scoring is pivotal both in routine diagnostics and larger multi-center studies aiming at improving present or establishing new cut-off values for existing or novel therapy regimens. However, recent studies have cast some doubt on the reliability of “visual” Ki67 scoring by pathologists, especially within the lower - yet clinically important - proliferation range. Here, we present and apply a novel automated image analysis approach for Ki67-quantification in breast cancer tissue.

Methods: We perform automated Ki67-scoring in 1219 breast cancer patients from the GeparTrio study cohort using a novel image analysis approach that avoids detection biases due to morphological variability by using a generic minimum-model approach. The method is capable of tumor-stroma-separation and may be used to process large data sets fully unsupervised in batch mode while allowing for efficient visual checks of the results. We compare these results with a different in-house-developed subtiling-based automated quantification method and moreover, gauge our approach with manual scoring performed by pathologists.

Results: The results show deviations of 10% (automated method 1 vs. manual), 9% (automated method 2 vs. manual) and 3% (automated method 1 vs. automated method 2) on average. The Ki67 scores show Pearson correlations between automated and manual scoring of r&gt;0.8 (p &lt; 0.001) for both automated methods and r&gt;0.95 (p &lt; 0.001) between the two tested automated methods.

Conclusion: Because of the methodological differences of the presented techniques our results suggest a high robustness of the automated methods that at the same time show a good agreement with manual Ki67 scoring. Our approach therefore offers an automated and standardized means of Ki67 quantification applicable in routine diagnostics as well as larger clinical study settings, such as in the GeparTrio cohort shown here.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr PD06-01.

Abstract P1-14-01: Adding capecitabine and trastuzumab to neoadjuvant breast cancer chemotherapy - first survival analysis of the GBG/AGO intergroup-study GeparQuattro

Background: Previous results of the GeparQuattro study demonstrated that adding capecitabine either simultaneously or sequentially to EC-Docetaxel (D) neoadjuvant chemotherapy could not increase pathological complete response rates (pCR) (von Minckwitz G, JCO 2010). However, patients with HER2-positive disease treated simultaneously with trastuzumab showed a significant higher pCR rate than patients with HER2-negative disease treated with chemotherapy alone (Untch M, JCO 2010). We here report survival after a median follow up of 58 months including 279 relapses and 191 deaths.

Patients and methods: Patients with either large operable (cT3) and locally advanced (cT4) tumors, or hormone-receptor (HR)-negative receptor status, or HR-positive tumors but clinically node-positive disease were recruited to receive 4 cycles of EC (90mg/m2/600mg/m2) and randomized to either 4 cycles of D (100mg/m2) or 4 cycles of DX (75mg/m2/1800mg/m2) or 4 cycles of D (75mg/m2) followed by 4 cycles of X (1800mg/m2) (D→X). Patients with HER-2 positive tumors received 1 year of trastuzumab, the first part concurrent to all chemotherapy cycles. All patients with HR+ tumors received endocrine therapy according to current standard. The intent-to-treat survival analysis included 1421 patients for the chemotherapy question and 1495 patients for the trastuzumab question. Analyses were adjusted by age, stage, size, nodal status, histologic type, grade, hormone-receptor (HR) and HER2-status at baseline (if applicable).

Results: No difference in DFS and OS was seen for patients receiving D, DX or D-X overall (hazard ratio 0.978, p = 0.984 and hazard ratio 0.986, p = 0.684, respectively) as well as by phenotype defined according to St. Gallen (all P&gt;0.354).

Patients with HER2-positive disease treated additionally with trastuzumab showed significantly better OS (p = 0.015) compared to patients with HER2-negative disease treated with chemotherapy alone. DFS was significantly better for trastuzumab-treated patients with HR-negative tumors (p = 0.046), but not with HR-positive tumors (p = 0.790). OS after first relapse was significantly better in trastuzumab-retreated patients with HER2-positive tumors (p = 0.032) compared to relapsed patients with HER2-negative tumors.

Patients with an early response after 4 cycles, with a clinical response at surgery and with a pCR showed a significantly better DFS and OS compared to patients without pCR (p = 0.022, P &lt; 0.0001, P &lt; 0.0001). This benefit was most prominent in patients with triple-negative tumors.

Conclusions: Survival analysis of the GeparQuattro study confirmed the results of the primary endpoint analysis on pCR. Capecitabine could not improve outcome when added to anthracycline-taxane-based chemotherapy. As suggested by a recent integrated multi-level meta-analysis (von Minckwitz, BCRT 2011) effect of capecitabine could not be properly assessed in this study as planned docetaxel doses in arms DX and D®X were lower than in arm D. Survival of HER-2 positive patients surmounts that of HER2-negative patients if trastuzumab is used in the neoadjuvant as well as in the metastatic setting.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-14-01.

Abstract S4-5: Ki67 levels in pretherapeutic core biopsies as predictive and prognostic parameters in the neoadjuvant GeparTrio trial

Background: Ki67 has been suggested as a marker for definition of luminal A and luminal B tumors by the 2011 St. Gallen consensus panel. However, the cutoffs for Ki67 are still under debate. In particular, it is not clear if one single cutoff is useful for prognostic and predictive information in the different molecular subtypes. It is an advantage of the neoadjuvant approach that predictive and prognostic outcome measurements can be separated in the same cohort. In this study, we evaluated a large cohort of core biopsies from the neoadjuvant GeparTrio trial to investigate the impact of pretherapeutic Ki67 levels as a predictive marker for response to neoadjuvant chemotherapy as well as a prognostic marker for progression-free and overall survival. The analysis was stratified for hormone-receptor positive and negative tumors as well as HER2 status.

Methods: A total of 1166 pretherapeutic core biopsies from the neoadjuvant Gepartrio trial were evaluated for Ki67 by immunohistochemistry, a total of 200 cells were counted in each sample. Ki67 cutoffs were evaluated using web-based software Cutoff Finder (http://molpath.charite.de/cutoff/). The details of the GeparTrio study design have been described before (von Minckwitz, JNCI 2008). We compared pCR rate as well as the overall and disease free survival in the complete cohort as well as subgroups of patients based on hormone receptor and HER2 expression.

Results: Using Ki67 as a continuous parameter, a wide range of cutoffs between 10% and 80% for Ki67 were predictive for pCR. For DFS and OS, a wide range of cutoffs between 10% and 45% was significant. For further analysis, the three groups of Ki67 0–15% vs. Ki67 15.1%–35% vs. Ki67 &gt;35 were defined and were compared for different outcome parameters. The pCR rates in these three groups of Ki67 expression were 4.2%, 12.9% and 29.0% (p &lt; 0.0005). For DFS and OS, the groups were significantly linked to prognosis in univariate and multivariate analysis. A detailed subgroup analysis was performed showing that Ki67 was significantly predictive for pCR in all molecular subgroups. However, in subgroup survival analysis, Ki67 was prognostic in luminal, but not in triple-negative tumors.

Conclusion: Ki67 is a valid predictive and prognostic marker in breast cancer. This marker is significant over a wide range of different cutoffs, which explains the different results of Ki67 cutoffs in different previous studies. Therefore, the variability observed in different studies evaluating Ki67 might reflect A) the wide range of valid cutoffs B) the different clinical endpoints of the studies and C) the different contribution of the molecular subtypes in the study cohorts. Based on our results we suggest three subgroups for Ki67 (0–15% vs. 15.1–35 vs. &gt;35%) as a reasonable approach for further standardization of this marker.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr S4-5.

Abstract OT1-1-13: Dual blockade with Afatinib and Trastuzumab as neooadjuvant treatment for patients with locally advanced or operable breast cancer receiving taxane-anthracycline containing chemotherapy (DAFNE)-GBG70

Background: Anthracycline/taxane based combination chemotherapy of at least 18 weeks represents the standard of care in the neoadjuvant setting. In HER2 positive disease trastuzumab is given concurrently to chemotherapy and achieves a pCR rate (no invasive residuals in breast and nodes) of approx. 40% which can be increased by double anti HER2 blockade by approximately 20%. There are no data on the combination of afatinib (BIBW 2992), an irreversible HER family inhibitor with trastuzumab.

Methods: This is a multi-centre, prospective, open-label phase II study evaluating the efficacy and safety of afatinib in combination with weekly paclitaxel + trastuzumab followed by epirubicin/cyclophosphamide/trastuzumab as neoadjuvant therapy in patients with untreated HER2-positive early breast cancer. Pts with histologically confirmed, centrally reviewed HER2 positive, unilateral, primary operable or locally advanced breast cancer can be included. Tumor size has to be at least 2cm by sonography.

All patients will be treated for a total duration of 30 weeks (6 weeks with afatinib (20mg) and trastuzumab (8/6mg/kg) alone, 12 weeks with weekly paclitaxel (80mg/m2), afatinib and trastuzumab and 12 weeks with epirubicin/cyclophosphamide/trastuzumab according to standard). During the first 2 weeks afatinib 20 mg will be given only every other day to reduce the risk of diarrhea and skin toxicities. Primary prophylaxis with loperamide 2×2 mg daily is obligatory during the first 4 weeks of afatinib/trastuzumab and the first 2 weeks of afatinib/trastuzumab/paclitaxel. Thereafter prophylaxis with loperamide can be stopped if no diarrhea grade &gt; 1 occurred.

Primary objective is pathological complete response (pCR = ypT0/is ypN0). Secondary objectives are pCR by other definitions, clinical response rates, rate and type of surgery, toxicity and compliance, pCR related to skin toxicity and diarrhoea and pre-specified molecular markers. An extensive biomaterial collection is integreated, including obligatory biomaterial (e.g. skin biopsies) collection at baseline, prior to start of paclitaxel at the end of paclitaxel and prior to surgery.

Neoadjuvant anthracycline-taxane-based chemotherapy given simultaneously with trastuzumab after central HER 2-testing results in a pCR rate of approx. 50%. The addition of a dual anti HER2 blockade to chemotherapy increased the pCR by absolute 20%. A pCR rate of 70% is expectedand and a pCR rate of 55% or lower excluded; with α=0.1 and 1-ß=80%, this requires 65 evaluable patients for two-sided one group χ2-test. An integrated safety phase is planned for the first 15 patients entering the study.

The trial is registered under NCT015591477. It is financially supported by Boehringer Ingelheim.

Results: Centres have been initiated after approval by ethics committee and authorities. Three patients have been recruited. It is planned to recruit 12 months in 15 sites in Germany.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr OT1-1-13.

The 21-gene recurrence score assay impacts adjuvant therapy recommendations for ER-positive, node-negative and node-positive early breast cancer resulting in a risk-adapted change in chemotherapy use

Background

We carried out a prospective clinical study to evaluate the impact of the Recurrence Score (RS) on treatment decisions in early breast cancer (EBC).

Patients and methods

A total of 379 eligible women with estrogen receptor positive (ER+), HER2-negative EBC and 0–3 positive lymph nodes were enrolled. Treatment recommendations, patients' decisional conflict, physicians' confidence before and after knowledge of the RS and actual treatment data were recorded.

Results

Of the 366 assessable patients 244 were node negative (N0) and 122 node positive (N+). Treatment recommendations changed in 33% of all patients (N0 30%, N+ 39%). In 38% of all patients (N0 39%, N+ 37%) with an initial recommendation for chemoendocrine therapy, the post-RS recommendation changed to endocrine therapy, in 25% (N0 22%, N+ 39%) with an initial recommendation for endocrine therapy only to combined chemoendocrine therapy, respectively. A patients' decisional conflict score improved by 6% (P = 0.028) and physicians' confidence increased in 45% (P < 0.001) of all cases. Overall, 33% (N0 29%, N+ 38%) of fewer patients actually received chemotherapy as compared with patients recommended chemotherapy pre-test. Using the test was cost-saving versus current clinical practice.

Conclusion

RS-guided chemotherapy decision-making resulted in a substantial modification of adjuvant chemotherapy usage in node-negative and node-positive ER+ EBC.

PD07-05: Local Recurrence Risk in 6377 Patients with Early Breast Cancer Receiving Neoadjuvant Anthracycline-Taxane +/− Trastuzumab Containing Chemotherapy

Background: Locoregional recurrence (LRR; defined according to Hudis C, JCO 2007) risk after neoadjuvant systemic treatment is considered as a possible hazard of this treatment approach. However, few data exist on the incidence and risk factors for LRR after anthracycline-taxane+/−trastuzumab (AT+/−H) containing neoadjuvant treatment. We analyzed individual data of 7 prospective neoadjuvant trials conducted by the German Breast Group and the AGO Breast Group.

Patients (Pts) and methods: 6377 Pts with operable or locally advanced, non-metastatic breast cancer were analyzed (for details see von Minckwitz G et al, BCRT 2010). Postsurgical radiotherapy was indicated after breast conservation for all patients and after mastectomy for patients with cT3/4 or cN+ disease. Endocrine treatment was given to ER− and/or PgR-positive patients. 485 LRR were observed during a median follow up of 46.2 (0-127) months.

Results: LRR was similar for patients treated by tumorectomy (7.2% of N=1123), segmentectomy (6.8% of N=1121), quadrantectomy (7% of 557), or breast conservation (BCT) (not otherwise specified) (7.7% of N=819), but higher in patients treated by mastectomy (ME) (12.1% of N=1670) (p&lt;0.001). Rate of breast conservation decreased by increasing initial tumor size (cT1(N=198): 77.7%, cT2(N=3675): 78.1%, cT3(N=795): 49.4%, cT4a-c(N=348): 35.9%, cT4d(N=235):19.1%). LRR in patients treated by BCT or ME were 9.1% vs 9.1% for cT1 (p=0.9); 6.9% vs. 9.8% for cT2 (p=0.001); 9.7% vs 14.2% for cT3 (p=0.04); 3.2% vs. 11.7% for cT4a-c (p=0.004; and 22.2% vs 18.9% for cT4d (p=0.4). LRR increased with surgical yT-stage from 4.7% for ypT0 (N=990), 11.8% for ypTis (N=340), 9.1% for ypT1 (N=1555), 8.2% for ypT2 (N=926), 13.8% for ypT3 (N=232), 20% ypT4a-c (N=80), to 31.2% for ypT4d (N=16) (p&lt;0.001). Comparable results were obtained for cN and ypN stages. Patients with a pathological complete response (pCR = ypT0 ypN0) showed a lower LRR of 3.7% compared to patients not achieving a pCR (3.7% vs 9.9% (HR 0.36 p&lt;0.001). Patients with a pCR showed low LRR in all intrinsic subtypes except Luminal B/HER2+ -like tumors (Luminal A-like tumors (N=105; 3.8%), Luminal B/HER2− -like (N=40; 0%), Luminal B/Her2+ -like (N=124; 8.1%), HER2+(non-luminal)-like (N=158; 1.9%), triple-negative (N=276; 2.5%) (p=0.016). Patients without a pCR showed an excessive LRR for HER2+(non-luminal) and triple-negative tumors (Luminal A-like tumors (N=1498; 5.1%), Luminal B/HER2− -like (N=304; 11.9%), Luminal B/HER2+ -like (N=602; 8.5%), HER2+(non-luminal)-like (N=367; 18%) and triple-negative (N=276; 17.8%) (p&lt;0.001). cT, cN, ypN, intrinsic subtype, but not ypT stage and type of surgery were independent predictors of LRR for patients without pCR in a Cox regression model. None of these factors except Luminal B/HER2+ (p=0.012) were significant in patients with pCR.

Conclusions: LRR in this large pooled analysis after AT+/−H containing neoadjuvant treatment appears to be low, especially in all patients with a pCR except Luminal B/HER2+ disease. In patients without a pCR low cT, cN, ypN and Luminal tumor type predict a low LRR. Other stages and subtypes without pCR should be carefully followed up irrespective of type of surgery.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr PD07-05.

Lapatinib Can Be Safely Given Concomitantly to EC-Doc as Neoadjuvant Chemotherapy for Breast Cancer. First Planned Safety Analysis of the Geparquinto Study (GBG 44)

Background:Trastuzumab has significantly improved pathological complete response rates of neoadjuvant treatment in HER2 positive breast cancer (HER2+BC). The tyrosine-kinase inhibitor lapatinib (L) has shown efficacy in metastatic breast cancer. Previous data in metastatic breast cancer suggested increased hematologic toxicity of docetaxel (Doc) combined with L. As the dose and safety of L in combination with epirubicin (E), cyclophosphamide (C), and Doc has not yet been adequately tested, an integrated safety phase was conducted.Patients and Methods:The GeparQuinto trial, a neoadjuvant phase III study, planned to include 2500 patients (pts) in total and 594 HER2+BC pts for comparing L versus trastuzumab (H) given concomitantly to anthracycline-taxane based chemotherapy. Female pts with untreated, histologically confirmed uni- or bilateral, cT3/4a-d, HER2+BC and no clinically relevant cardiovascular co-morbidities received 4 cycles of E (90mg/m²) + C (600 mg/m²) q3w followed by Doc 100mg/ m² q3w. Pts were randomized to receive either H (6 mg/kg; 8mg/kg loading dose; q3w) or L given concomitantly to all cycles. The 1st cohort in the L arm received 1000 mg/d L during the 1st cycle EC and the 1st cycle Doc and 1250 mg/d L through all other cycles and received prophylactic treatment with pegfilgrastim (6 mg on day 2) and loperamide (2x2mg daily). The 2nd cohort received no loperamide, if &lt;=1 diarrhea grade 3 and no pegfilgrastim if &lt;=3 events of grade 4 neutropenia and &lt;=1 febrile neutropenia (FN) occurred during cycles 1+2 of the 1st 10 pts of the 1st cohort. The remaining pts received 1250 mg/d L in the first cycle and no prophylaxis with loperamide if &lt;=2 diarrhea grade 3 and &lt;= 1 diarrhea grade 4 and no pegfilgrastim if &lt;=4 events of grade 4 neutropenia and &lt;=2 FN occurred during cycles 1+2 of the 1st 10 pts of the 2nd cohort. An interim safety analysis was planned when 60 pts completed all cycles.Results:As of June 1 2009 918 (178 HER+BC) pts have been recruited. 31 pts received ECH-DocH and 29 pts ECL-DocL. In the 1st cohort no grade 3 diarrhea and 2 grade 4 neutropenias occurred. In the 2nd cohort again, no grade diarrhea 3, but 8 grade 4 neutropenias (1 FN) occurred in 4 pts. L was, when compared to H, associated with less grade 1/2 anemia (27.6% vs. 51.6.%) but more grade 1/2 skin rash (27.6% vs. 6.5%) during cycle 1 (data on all cycles will be presented). No significant differences for other toxicities were seen.Conclusion:L at a dose of 1250 mg/d is feasible and well tolerated when given concomitantly to EC-Doc if G-CSF is given prophylactically during DocL.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1094.

Toxicity analysis of a phase III study evaluating FEC-Doc vs. FEC-Doc in combination with gemcitabine as adjuvant treatment for breast cancer – the SUCCESS-trial

Abstract #4108

Background:&#x2028; Taxane containing regimens have been established as standard of care for node-positive primary breast cancer patients and have shown superiority to mere anthracycline containing regimens. The SUCCESS-trial evaluates, whether adjuvant taxane based treatment can be further improved by the addition of Gemcitabine.&#x2028; Methods:&#x2028; The SUCCESS-Study is an open-label randomized controlled, Phase III study comparing the disease free survival after randomisation in patients treated with 3 cycles of Epirubicin(100 mg/m²)-Fluorouracil(500)-Cyclophosphamide(500, FEC)-chemotherapy, followed by 3 cycles of Docetaxel(100 mg/mg², D) versus 3 cycles of FEC, followed by 3 cycles of Gemcitabine(1,000mg/m² d1,8)-Docetaxel(75 mg/m²)(DG). Complete, monitored toxicity data of 2.691 pts were available for this analysis.&#x2028; Results:&#x2028; Dose reduction &gt;20% (3.97% vs 2.90%) and postponement of treatment cycles &gt;7die (22,85% vs 14.19%) was rare, but more frequent in the FEC-DG arm (both p&lt; .001). Cytostatic treatment was prematurely stopped in 119 pts (4,4%) receiving FEC-DG and in 103 pts (3,8%) with FEC-D (p=0,21). G-CSF support was applied in 850 (29.2%) vs. 602 pts (20.7%, p&lt; .001). Toxicities NCI grade &gt; 2 which occurred with incidence &gt; 1% or significantly different in the two arms are depicted in Table 1. Afebrile and febrile neutropenia and anemia did not differ between the two arms, but thrombocytopenia was more frequent in FEC-DG (1.7%, p= .007). Hand-foot syndrome and neuropathy was more frequent in the FEC-D arm (p= .09 and p= .02, respectively).&#x2028; Conclusion:&#x2028; No unexpected toxicities were observed and severe adverse effects were rare in both treatment arms. With the addition of gemcitabine to FEC-D adjuvant chemotherapy toxicity was moderately increased. Outcome data will have to be awaited to further interpret these findings.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4108.