Holger Eidtmann

Definition and Impact of Pathologic Complete Response on Prognosis After Neoadjuvant Chemotherapy in Various Intrinsic Breast Cancer Subtypes

PURPOSE The exact definition of pathologic complete response (pCR) and its prognostic impact on survival in intrinsic breast cancer subtypes is uncertain. METHODS Tumor response at surgery and its association with long-term outcome of 6,377 patients with primary breast cancer receiving neoadjuvant anthracycline-taxane-based chemotherapy in seven randomized trials were analyzed. RESULTS Disease-free survival (DFS) was significantly superior in patients with no invasive and no in situ residuals in breast or nodes (n = 955) compared with patients with residual ductal carcinoma in situ only (n = 309), no invasive residuals in breast but involved nodes (n = 186), only focal-invasive disease in the breast (n = 478), and gross invasive residual disease (n = 4,449; P < .001). Hazard ratios for DFS comparing patients with or without pCR were lowest when defined as no invasive and no in situ residuals (0.446) and increased monotonously when in situ residuals (0.523), no invasive breast residuals but involved nodes (0.623), and focal-invasive disease (0.727) were included in the definition. pCR was associated with improved DFS in luminal B/human epidermal growth factor receptor 2 (HER2) -negative (P = .005), HER2-positive/nonluminal (P < .001), and triple-negative (P < .001) tumors but not in luminal A (P = .39) or luminal B/HER2-positive (P = .45) breast cancer. pCR in HER2-positive (nonluminal) and triple-negative tumors was associated with excellent prognosis. CONCLUSION pCR defined as no invasive and no in situ residuals in breast and nodes can best discriminate between patients with favorable and unfavorable outcomes. Patients with noninvasive or focal-invasive residues or involved lymph nodes should not be considered as having achieved pCR. pCR is a suitable surrogate end point for patients with luminal B/HER2-negative, HER2-positive (nonluminal), and triple-negative disease but not for those with luminal B/HER2-positive or luminal A tumors.

Pathological complete response and long-term clinical benefit in breast cancer: the CTNeoBC pooled analysis

BACKGROUND Pathological complete response has been proposed as a surrogate endpoint for prediction of long-term clinical benefit, such as disease-free survival, event-free survival (EFS), and overall survival (OS). We had four key objectives: to establish the association between pathological complete response and EFS and OS, to establish the definition of pathological complete response that correlates best with long-term outcome, to identify the breast cancer subtypes in which pathological complete response is best correlated with long-term outcome, and to assess whether an increase in frequency of pathological complete response between treatment groups predicts improved EFS and OS. METHODS We searched PubMed, Embase, and Medline for clinical trials of neoadjuvant treatment of breast cancer. To be eligible, studies had to meet three inclusion criteria: include at least 200 patients with primary breast cancer treated with preoperative chemotherapy followed by surgery; have available data for pathological complete response, EFS, and OS; and have a median follow-up of at least 3 years. We compared the three most commonly used definitions of pathological complete response--ypT0 ypN0, ypT0/is ypN0, and ypT0/is--for their association with EFS and OS in a responder analysis. We assessed the association between pathological complete response and EFS and OS in various subgroups. Finally, we did a trial-level analysis to assess whether pathological complete response could be used as a surrogate endpoint for EFS or OS. FINDINGS We obtained data from 12 identified international trials and 11 955 patients were included in our responder analysis. Eradication of tumour from both breast and lymph nodes (ypT0 ypN0 or ypT0/is ypN0) was better associated with improved EFS (ypT0 ypN0: hazard ratio [HR] 0·44, 95% CI 0·39-0·51; ypT0/is ypN0: 0·48, 0·43-0·54) and OS (0·36, 0·30-0·44; 0·36, 0·31-0·42) than was tumour eradication from the breast alone (ypT0/is; EFS: HR 0·60, 95% CI 0·55-0·66; OS 0·51, 0·45-0·58). We used the ypT0/is ypN0 definition for all subsequent analyses. The association between pathological complete response and long-term outcomes was strongest in patients with triple-negative breast cancer (EFS: HR 0·24, 95% CI 0·18-0·33; OS: 0·16, 0·11-0·25) and in those with HER2-positive, hormone-receptor-negative tumours who received trastuzumab (EFS: 0·15, 0·09-0·27; OS: 0·08, 0·03, 0·22). In the trial-level analysis, we recorded little association between increases in frequency of pathological complete response and EFS (R(2)=0·03, 95% CI 0·00-0·25) and OS (R(2)=0·24, 0·00-0·70). INTERPRETATION Patients who attain pathological complete response defined as ypT0 ypN0 or ypT0/is ypN0 have improved survival. The prognostic value is greatest in aggressive tumour subtypes. Our pooled analysis could not validate pathological complete response as a surrogate endpoint for improved EFS and OS. FUNDING US Food and Drug Administration.

Lapatinib with trastuzumab for HER2-positive early breast cancer (NeoALTTO): a randomised, open-label, multicentre, phase 3 trial

BACKGROUND The anti-HER2 monoclonal antibody trastuzumab and the tyrosine kinase inhibitor lapatinib have complementary mechanisms of action and synergistic antitumour activity in models of HER2-overexpressing breast cancer. We argue that the two anti-HER2 agents given together would be better than single-agent therapy. METHODS In this parallel groups, randomised, open-label, phase 3 study undertaken between Jan 5, 2008, and May 27, 2010, women from 23 countries with HER2-positive primary breast cancer with tumours greater than 2 cm in diameter were randomly assigned to oral lapatinib (1500 mg), intravenous trastuzumab (loading dose 4 mg/kg [DOSAGE ERROR CORRECTED], subsequent doses 2 mg/kg), or lapatinib (1000 mg) plus trastuzumab. Treatment allocation was by stratified, permuted blocks randomisation, with four stratification factors. Anti-HER2 therapy alone was given for the first 6 weeks; weekly paclitaxel (80 mg/m(2)) was then added to the regimen for a further 12 weeks, before definitive surgery was undertaken. After surgery, patients received adjuvant chemotherapy followed by the same targeted therapy as in the neoadjuvant phase to 52 weeks. The primary endpoint was the rate of pathological complete response (pCR), analysed by intention to treat. This trial is registered with ClinicalTrials.gov, NCT00553358. FINDINGS 154 patients received lapatinib, 149 trastuzumab, and 152 the combination. pCR rate was significantly higher in the group given lapatinib and trastuzumab (78 of 152 patients [51·3%; 95% CI 43·1-59·5]) than in the group given trastuzumab alone (44 of 149 patients [29·5%; 22·4-37·5]; difference 21·1%, 9·1-34·2, p=0·0001). We recorded no significant difference in pCR between the lapatinib (38 of 154 patients [24·7%, 18·1-32·3]) and the trastuzumab (difference -4·8%, -17·6 to 8·2, p=0·34) groups. No major cardiac dysfunctions occurred. Frequency of grade 3 diarrhoea was higher with lapatinib (36 patients [23·4%]) and lapatinib plus trastuzumab (32 [21·1%]) than with trastuzumab (three [2·0%]). Similarly, grade 3 liver-enzyme alterations were more frequent with lapatinib (27 [17·5%]) and lapatinib plus trastuzumab (15 [9·9%]) than with trastuzumab (11 [7·4%]). INTERPRETATION Dual inhibition of HER2 might be a valid approach to treatment of HER2-positive breast cancer in the neoadjuvant setting. FUNDING GlaxoSmithKline.

Neoadjuvant Treatment With Trastuzumab in HER2-Positive Breast Cancer: Results From the GeparQuattro Study

PURPOSE Trastuzumab, a humanized antibody against the human epidermal growth factor receptor type 2 (HER2), has shown high efficacy in breast cancer. We prospectively investigated its efficacy given simultaneously with anthracycline-taxane-based neoadjuvant chemotherapy. PATIENTS AND METHODS Patients with operable or locally advanced, HER2-positive tumors were treated preoperatively with four cycles of epirubicin/cyclophosphamide followed by four cycles of docetaxel with or without capecitabine (EC-T[X]) and trastuzumab 6 mg/kg (with a loading dose of 8 mg/kg) every 3 weeks during all chemotherapy cycles. Patients with HER2-negative tumors treated in the same study with the same chemotherapy but without trastuzumab were used as a reference group. Results Of 1,509 participants, 445 had HER2-positive tumors treated with trastuzumab and chemotherapy. Pathologic complete response (pCR; defined as no invasive or in situ residual tumors in the breast) rate was 31.7%, which was 16% higher than that in the reference group (15.7%). HER2-positive patients without response to the first four cycles of EC showed an unexpectedly high pCR rate of 16.6% (3.3% in the reference group). Breast conservation rate was 63.1% and comparable to that of the reference group (64.7%). EC-T(X) plus trastuzumab was associated with more febrile neutropenia and conjunctivitis, but with a comparable short-term cardiac toxicity profile as the reference group. CONCLUSION This trial confirms that combining trastuzumab with anthracycline-taxane-based neoadjuvant chemotherapy results in a high pCR rate without clinically relevant early toxicity. Combination of chemotherapy with trastuzumab should be considered when neoadjuvant treatment is given to patients with HER2-positive breast cancer.

Neoadjuvant Chemotherapy and Bevacizumab for HER2-Negative Breast Cancer

BACKGROUND Bevacizumab, a monoclonal antibody against vascular endothelial growth factor A, has shown clinical efficacy in patients with human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer. We evaluated the efficacy, measured according to the rate of pathological complete response (absence of invasive and intraductal disease in the breast and the axillary lymph nodes), and the safety of adding bevacizumab to neoadjuvant chemotherapy in patients with early-stage breast cancer. METHODS We randomly assigned 1948 patients with a median tumor size of 40 mm on palpation to receive neoadjuvant epirubicin and cyclophosphamide followed by docetaxel, with or without concomitant bevacizumab. Patients with untreated HER2-negative breast cancer were eligible if they had large tumors, hormone-receptor-negative disease, or hormone-receptor-positive disease with palpable nodes or positive findings on sentinel-node biopsy, and no increased cardiovascular or bleeding risk. RESULTS Overall, the rates of pathological complete response were 14.9% with epirubicin and cyclophosphamide followed by docetaxel and 18.4% with epirubicin and cyclophosphamide followed by docetaxel plus bevacizumab (odds ratio with addition of bevacizumab, 1.29; 95% confidence interval, 1.02 to 1.65; P=0.04); the corresponding rates of pathological complete response were 27.9% and 39.3% among 663 patients with triple-negative tumors (P=0.003) and 7.8% and 7.7% among 1262 patients with hormone-receptor-positive tumors (P=1.00). Breast-conserving surgery was possible in 66.6% of the patients in both groups. The addition of bevacizumab, as compared with neoadjuvant therapy alone, was associated with a higher incidence of grade 3 or 4 toxic effects (febrile neutropenia, mucositis, the hand-foot syndrome, infection, and hypertension) but with a similar incidence of surgical complications. CONCLUSIONS The addition of bevacizumab to neoadjuvant chemotherapy significantly increased the rate of pathological complete response among patients with HER2-negative early-stage breast cancer. Efficacy was restricted primarily to patients with triple-negative tumors, in whom the pathological complete response is considered to be a reliable predictor of long-term outcome. (Funded by Sanofi-Aventis and Roche, Germany; ClinicalTrials.gov number, NCT00567554.).

Detection and HER2 Expression of Circulating Tumor Cells: Prospective Monitoring in Breast Cancer Patients Treated in the Neoadjuvant GeparQuattro Trial

Purpose: This study was aimed at detecting and characterizing circulating tumor cells (CTC) before and after neoadjuvant therapy (NT) in the peripheral blood of patients with breast cancer. Experimental Design: The clinical trial GeparQuattro incorporated NT approaches (epirubicin/cyclophosphamide prior to randomization to docetaxel alone, docetaxel in combination with capecitabine, or docetaxel followed by capecitabine) and additional trastuzumab treatment for patients with HER2-positive tumors. We used the Food and Drug Administration–approved CellSearch system for CTC detection and evaluation of HER2 expression and developed HER2 immunoscoring for CTC. Results: We detected ≥1 CTC/7.5 mL in 46 of 213 patients (21.6%) before NT and in 22 of 207 patients (10.6%) after NT (P = 0.002). Twenty (15.0%) initially CTC-positive cases were CTC-negative after NT, whereas 11 (8.3%) cases were CTC-positive after NT, although no CTC could be found before NT. CTC detection did not correlate with primary tumor characteristics. Furthermore, there was no association between tumor response to NT and CTC detection. HER2-overexpressing CTC were observed in 14 of 58 CTC-positive patients (24.1%), including 8 patients with HER2-negative primary tumors and 3 patients after trastuzumab treatment. CTC scored HER2-negative or weakly HER2-positive before or after NT were present in 11 of 21 patients with HER2-positive primary tumors. HER2 overexpression on CTC was restricted to ductal carcinomas and associated with high tumor stage (P = 0.002). Conclusion: CTC number was low in patients with primary breast cancer. The decrease in CTC incidence during treatment was not correlated with standard clinical characteristics and primary tumor response. Information on the HER2 status of CTC might be helpful for stratification and monitoring of HER2-directed therapies. Clin Cancer Res; 16(9); 2634–45. ©2010 AACR.

Doxorubicin With Cyclophosphamide Followed by Docetaxel Every 21 Days Compared With Doxorubicin and Docetaxel Every 14 Days As Preoperative Treatment in Operable Breast Cancer: The GEPARDUO Study of the German Breast Group

PURPOSE Dose-dense and sequential administration of cytotoxic drugs are current approaches to improve outcomes in patients with early-stage breast cancer. METHODS This phase III study investigated 913 women with untreated operable breast cancer (T2-3, N0-2, M0) randomly assigned to receive either doxorubicin 50 mg/m2 plus docetaxel 75 mg/m2 every 14 days for four cycles with filgrastim support (ADOC), or doxorubicin 60 mg/m2 plus cyclophosphamide 600 mg/m2 every 21 days followed by docetaxel 100 mg/m2 every 21 days for four cycles each (AC-DOC). The primary end point was the incidence of pathologic complete (invasive and noninvasive) response (pCR) in the breast and axillary nodes. Secondary end points were predictors for pCR, clinical response, rate of breast conservation, and safety. RESULTS A pCR was achieved in 94 patients (10.6%), but the likelihood was significantly greater with AC-DOC (14.3%; n = 63) than with ADOC (7.0%; n = 31) (odds ratio, 2.22; 90% CI, 1.52 to 3.24; P < .001). Independent predictors of attaining a pCR included the use of sequential therapy, high tumor grade, and negative hormone receptor status. The response rates detected by palpation and by imaging were significantly higher with AC-DOC (85.0% and 78.6%, respectively) than with ADOC (75.2% and 68.6%, respectively; both P values < .001). The rate of breast-conserving surgery was 63.4% for AC-DOC and 58.1% for ADOC (P = .05). Predominant grade 3/4 toxicities were leucopenia (AC-DOC, 74.2%; ADOC, 53.7%) and neutropenia (AC-DOC, 66.4%; ADOC, 44.7%) but were infrequently associated with fever (AC-DOC, 4.6%; ADOC, 3.1%). CONCLUSION Sequential AC-DOC is more effective at inducing pCR than dose-dense ADOC as preoperative treatment for patients with operable breast cancer.

Neoadjuvant carboplatin in patients with triple-negative and HER2-positive early breast cancer (GeparSixto; GBG 66): a randomised phase 2 trial

BACKGROUND Preclinical data suggest that triple-negative breast cancers are sensitive to interstrand crosslinking agents, and that synergy may exist for the combination of a taxane, trastuzumab, and a platinum salt for HER2-positive breast cancer. We therefore aimed to assess the efficacy of the addition of carboplatin to neoadjuvant therapy for triple-negative and HER2-positive breast cancer. METHODS Patients with previously untreated, non-metastatic, stage II-III, triple-negative breast cancer and HER2-positive breast cancer were enrolled. Patients were treated for 18 weeks with paclitaxel (80 mg/m(2) once a week) and non-pegylated liposomal doxorubicin (20 mg/m(2) once a week). Patients with triple-negative breast cancer received simultaneous bevacizumab (15 mg/kg intravenously every 3 weeks). Patients with HER2-positive disease received simultaneous trastuzumab (8 mg/kg initial dose with subsequent doses of 6 mg/kg intravenously every 3 weeks) and lapatinib (750 mg daily). Patients were randomly assigned in a 1:1 ratio with dynamic allocation and minimisation, stratified by biological subtype and Ki-67 level to receive, at the same time as the backbone regimens, either carboplatin (AUC 1·5 [2·0 for the first 329 patients] once a week) or no carboplatin. The primary endpoint the proportion of patients who achieved a pathological complete response (defined as ypT0 ypN0), analysed for all patients who started treatment; a p value of less than 0·2 was deemed significant for the primary endpoint. This trial is registered with ClinicalTrials.gov, number NCT01426880. FINDINGS 296 patients were randomly assigned to receive carboplatin and 299 to no additional carboplatin, of whom 295 and 293 started treatment, respectively. In this final analysis, 129 patients (43·7%, 95% CI 38·1-49·4) in the carboplatin group achieved a pathological complete response, compared with 108 patients (36·9%, 31·3-42·4) without carboplatin (odds ratio 1·33, 95% CI 0·96-1·85; p=0·107). Of the patients with triple-negative breast cancer, 84 (53·2%, 54·4-60·9) of 158 patients achieved a pathological complete response with carboplatin, compared with 58 (36·9%, 29·4-44·5) of 157 without (p=0·005). Of the patients with HER2-positive tumours, 45 (32·8%, 25·0-40·7) of 137 patients achieved a pathological complete response with carboplatin compared with 50 (36·8%, 28·7-44·9) of 136 without (p=0·581; test for interaction p=0·015). Haematological and non-haematological toxic effects that were significantly more common in the carboplatin group than in the no-carboplatin group included grade 3 or 4 neutropenia (192 [65%] vs 79 [27%]), grade 3 or 4 anaemia (45 [15%] vs one [<1%]), grade 3 or 4 thrombocytopenia (42 [14%] vs one [<1%]), and grade 3 or 4 diarrhoea (51 [17%] vs 32 [11%]); carboplatin was more often associated with dose discontinuations (141 [48%] with carboplatin and 114 [39%] without carboplatin; p=0·031). The frequency of grade 3 or 4 haematological events decreased from 82% (n=135) to 70% (n=92) and grade 3 or 4 non-haematological events from 78% (n=128) to 59% (n=77) in the carboplatin arm when the dose of carboplatin was reduced from AUC 2·0 to 1·5. INTERPRETATION The addition of neoadjuvant carboplatin to a regimen of a taxane, an anthracycline, and targeted therapy significantly increases the proportion of patients achieving a pathological complete response. This regimen seems to increase responses in patients with triple-negative breast cancer, but not in those with HER2-positive breast cancer. FUNDING GlaxoSmithKline, Roche, and Teva.

Lapatinib versus trastuzumab in combination with neoadjuvant anthracycline-taxane-based chemotherapy (GeparQuinto, GBG 44): a randomised phase 3 trial

BACKGROUND We compared the efficacy and safety of the addition of lapatinib versus trastuzumab to anthracycline-taxane-based neoadjuvant chemotherapy. METHODS In the GeparQuinto randomised phase 3 trial, patients with untreated HER2-positive operable or locally advanced breast cancer were enrolled between Nov 7, 2007, and July 9, 2010. Patients were eligible if their tumours were classified as cT3/4a-d, or hormone receptor (HR)-negative, HR-positive with clinically node-positive and cT2 disease (cT2 cN+), or HR-positive and pathologically node-positive in the sentinel lymph node for those with cT1 disease (cT1 pN(SLN+)). Patients were randomly assigned in a 1:1 ratio to receive neoadjuvant treatment with four cycles of EC (epirubicin [90 mg/m(2) intravenously] plus cyclophosphamide [600 mg/m(2) intravenously], every 3 weeks), and four cycles of docetaxel (100 mg/m(2) intravenously every 3 weeks) with either trastuzumab (6 mg/kg intravenously, with a starting loading dose of 8 mg/kg, for eight cycles, every 3 weeks) or lapatinib (1000-1250 mg per day orally) throughout all cycles before surgery. Randomisation was done by dynamic allocation with the minimisation method of Pocock and patients were stratified by participating site, HR status, and extent of disease (cT1-3 cN0-2 vs T4 or N3). The primary endpoint was pathological complete response (defined as ypT0 and ypN0) and was analysed in all patients who received at least one cycle of EC. Participants and investigators were not masked to treatment assignment. Pathologists in centres assessing surgery outcomes were masked to group assignment. This trial is registered with ClinicalTrials.gov, number NCT00567554. FINDINGS Of 620 eligible patients, 309 were randomly assigned to chemotherapy with trastuzumab (ECH-TH group) and 311 to chemotherapy with lapatinib (ECL-TL group). Two patients in the ECH-TH group and three patients in the ECL-TL group did not start treatment because of withdrawal of consent or immediate surgery. 93 (30·3%) of 307 patients in the ECH-TH group and 70 (22·7%) of 308 patients in the ECL-TL group had a pathological complete response (odds ratio [OR] 0·68 [95%CI 0·47-0·97]; p=0·04). Chemotherapy with trastuzumab was associated with more oedema (119 [39·1%] vs 88 [28·7%]) and dyspnoea (90 [29·6%] vs 66 [21·4%]), and ECL-TL with more diarrhoea (231 [75·0%] vs 144 [47·4%]) and skin rash (169 [54·9%] vs 97 [31·9%]). 43 (14·0%) patients discontinued in the ECH-TH group and 102 (33·1%) in the ECL-TL group. 70 serious adverse events were reported in the ECH-TH group and 87 in the ECL-TL group. INTERPRETATION This direct comparison of trastuzumab and lapatinib showed that pathological complete response rate with chemotherapy and lapatinib was significantly lower than that with chemotherapy and trastuzumab. Unless long-term outcome data show different results, lapatinib should not be used outside of clinical trials as single anti-HER2-treatment in combination with neoadjuvant chemotherapy. FUNDING GlaxoSmithKline, Roche, and Sanofi-Aventis.

Efficacy of zoledronic acid in postmenopausal women with early breast cancer receiving adjuvant letrozole: 36-month results of the ZO-FAST Study

BACKGROUND Aromatase inhibitors (AIs) are accepted as adjuvant therapy for postmenopausal women (PMW) with hormone-responsive early breast cancer (EBC) with superior efficacy to tamoxifen. However, increased bone loss is associated with AIs. PATIENTS AND METHODS PMW with EBC receiving letrozole (2.5 mg/day for 5 years) were randomly assigned to immediate zoledronic acid (ZOL; 4 mg every 6 months) or delayed ZOL (initiated only for fracture or high risk thereof). RESULTS Patients (N = 1065) had a median age of 58 years; 54% had received prior adjuvant chemotherapy. At 36 months, mean change in L2-L4 bone mineral density (BMD) was +4.39% for immediate versus -4.9% for delayed ZOL (P < 0.0001). Between-group differences were 5.27% at 12 months, 7.94% at 24 months, and 9.29% at 36 months (P < 0.0001 for all). At 36 months, the immediate-ZOL group had a significant 41% relative risk reduction for disease-free survival (DFS) events (P = 0.0314). Adverse events are consistent with the known safety profiles of the study drugs. CONCLUSIONS At 36 months, immediate ZOL was more effective in preserving BMD during letrozole therapy. Immediate versus delayed ZOL led to significantly improved DFS. Benefits are observed in the context of a favorable, well-established safety profile for letrozole and ZOL.