Clinical and molecular characteristics of HER2-low-positive breast cancer: pooled analysis of individual patient data from four prospective, neoadjuvant clinical trials.

BACKGROUND: The development of anti-HER2 antibody-drug conjugates opens new therapeutic options for patients with breast cancer, including patients with low expression of HER2. To characterise this new breast cancer subtype, we have compared the clinical and molecular characteristics of HER2-low-positive and HER2-zero breast cancer, including response to neoadjuvant chemotherapy and prognosis. METHODS: In this pooled analysis of individual patient data, we evaluated a cohort of 2310 patients with HER2-non-amplified primary breast cancer that were treated with neoadjuvant combination chemotherapy in four prospective neoadjuvant clinical trials (GeparSepto, NCT01583426; GeparOcto, NCT02125344; GeparX, NCT02682693; Gain-2 neoadjuvant, NCT01690702) between July 30, 2012, and March 20, 2019. Central HER2 testing was done prospectively before random assignment of participants in all trials. HER2-low-positive status was defined as immunohistochemistry (IHC) 1+ or IHC2+/in-situ hybridisation negative and HER2-zero was defined as IHC0, based on the American Society of Clinical Oncology/College of American Pathologists guidelines. Disease-free survival and overall survival data were available for 1694 patients (from all trials except GeparX) with a median follow-up of 46·6 months (IQR 35·0-52·3). Bivariable and multivariable logistic regression models and Cox-proportional hazards models were performed based on a predefined statistical analysis plan for analysis of the endpoints pathological complete response, disease-free survival, and overall survival. FINDINGS: A total of 1098 (47·5%) of 2310 tumours were HER2-low-positive and 1212 (52·5%) were HER2-zero. 703 (64·0%) of 1098 patients with HER2-low-positive tumours were hormone receptor positive, compared with 445 (36·7%) of 1212 patients with HER2-zero tumours (p<0.0001). HER2-low-positive tumours had a significantly lower pathological complete response rate than HER2-zero tumours (321 [29·2%] of 1098 vs 473 [39·0%] of 1212, p=0·0002). Pathological complete response was also significantly lower in HER2-low-positive tumours versus HER2-zero tumours in the hormone receptor-positive subgroup (123 [17·5%] of 703 vs 105 [23·6%] of 445, p=0·024), but not in the hormone receptor-negative subgroup (198 [50·1%] of 395 vs 368 [48·0%] of 767, p=0·21). Patients with HER2-low-positive tumours had significantly longer survival than did patients with HER2-zero tumours (3-year disease-free survival: 83·4% [95% CI 80·5-85·9] vs 76·1% [72·9-79·0]; stratified log-rank test p=0·0084; 3-year overall survival: 91·6% [84·9-93·4] vs 85·8% [83·0-88·1]; stratified log-rank test p=0·0016). Survival differences were also seen in patients with hormone receptor-negative tumours (3-year disease-free survival: 84·5% [95% CI 79·5-88·3] vs 74·4% [70·2-78.0]; stratified log-rank test p=0·0076; 3-year overall survival: 90·2% [86·0-93·2] vs 84·3% [80·7-87·3], stratified log-rank test p=0·016), but not in patients with hormone receptor-positive tumours (3-year disease-free survival 82·8% [79·1-85·9] vs 79·3% [73·9-83·7]; stratified log-rank test p=0·39; 3-year overall survival 92·3% [89·6-94·4] vs 88·4% [83·8-91·8]; stratified log-rank test p=0·13). INTERPRETATION: Our results show that HER2-low-positive tumours can be identified as new subgroup of breast cancer by standardised IHC, distinct from HER2-zero tumours. HER2-low-positive tumours have a specific biology and show differences in response to therapy and prognosis, which is particularly relevant in therapy-resistant, hormone receptor-negative tumours. Our results provide a basis for a better understanding of the biology of breast cancer subtypes and the refinement of future diagnostic and therapeutic strategies. FUNDING: German Cancer Aid (Deutsche Krebshilfe).

Development of central nervous system metastases as a first site of metastatic disease in breast cancer patients treated in the neoadjuvant trials GeparQuinto and GeparSixto.

BACKGROUND: The incidence of central nervous system (CNS) metastases in breast cancer patients is rising and has become a major clinical challenge. Only few data are published concerning risk factors for the development of CNS metastases as a first site of metastatic disease in breast cancer patients. Moreover, the incidence of CNS metastases after modern neoadjuvant treatment is not clear. METHODS: We analyzed clinical factors associated with the occurrence of CNS metastases as the first site of metastatic disease in breast cancer patients after neoadjuvant treatment in the trials GeparQuinto and GeparSixto (n = 3160) where patients received targeted treatment in addition to taxane and anthracycline-based chemotherapy. RESULTS: After a median follow-up of 61 months, 108 (3%) of a total of 3160 patients developed CNS metastases as the first site of recurrence and 411 (13%) patients had metastatic disease outside the CNS. Thirty-six patients (1%) developed both CNS metastases and other distant metastases as the first site of metastatic disease. Regarding subtypes of the primary tumor, 1% of luminal A-like (11/954), 2% of luminal B-like (7/381), 4% of HER2-positive (34/809), and 6% of triple-negative patients (56/1008) developed CNS metastases as the first site of metastatic disease. In multivariate analysis, risk factors for the development of CNS metastases were larger tumor size (cT3-4; HR 1.63, 95% CI 1.08-2.46, p = 0.021), node-positive disease (HR 2.57, 95% CI 1.64-4.04, p < 0.001), no pCR after neoadjuvant chemotherapy (HR 2.29, 95% CI 1.32-3.97, p = 0.003), and HER2-positive (HR 3.80, 95% CI 1.89-7.64, p < 0.001) or triple-negative subtype (HR 6.38, 95% CI 3.28-12.44, p < 0.001). CONCLUSIONS: Especially patients with HER2-positive and triple-negative tumors are at risk of developing CNS metastases despite effective systemic treatment. A better understanding of the underlying mechanisms is required in order to develop potential preventive strategies.

Post-Mastectomy Radiotherapy After Neoadjuvant Chemotherapy in Breast Cancer: A Pooled Retrospective Analysis of Three Prospective Randomized Trials.

BACKGROUND: The impact of locoregional radiotherapy (RT) after neoadjuvant chemotherapy (NACT) and mastectomy in breast cancer patients is currently unclear. Several publications have suggested that patients with a favorable response to NACT might not benefit from RT after mastectomy. METHODS: A retrospective analysis of three prospective randomized NACT trials was performed. Information on the use of RT was available for 817 breast cancer patients with non-inflammatory breast cancer who underwent mastectomy after NACT within the GeparTrio, GeparQuattro, and GeparQuinto-trials. RT was administered to 676 of these patients (82.7%). RESULTS: The 5-year cumulative incidence of locoregional recurrence (LRR) was 15.2% (95% confidence interval [CI] 9.0-22.8%) in patients treated without RT and 11.3% in patients treated with RT (95% CI 8.7-14.3%). In the multivariate analysis, RT was associated with a lower risk of LRR (hazard ratio 0.51, 95% CI 0.27-1.0; p = 0.05). This effect was shown especially in patients with cT3/4 tumors, as well as in patients who were cN+ before neoadjuvant therapy, including those who converted to ypN0 after neoadjuvant therapy. In the bivariate analysis, disease-free survival was significantly worse in patients who received RT, however this was not confirmed in the multivariate analysis. CONCLUSIONS: Our results suggest that RT reduces the LRR rates in breast cancer patients who receive a mastectomy after NACT without an improvement in DFS. Prospective randomized controlled trials such as the National Surgical Adjuvant Breast and Bowel Project B-51/RTOG 1304 trial will analyze whether RT has any benefit in patients who have a favorable response after NACT.

Pattern of care of adjuvant radiotherapy in male breast cancer patients in clinical practice: an observational study.

BACKGROUND AND PURPOSE: Due to the rarity of male breast cancer (male BC), no consensus has been reached regarding the most appropriate curative treatment strategy. The objective of the present observational study was to identify patient and tumor characteristics and assess the role of radiotherapy (RT) in clinical practice. METHODS: Between 1998 and 2014, data of male BC patients treated at two breast centers were consecutively collected and retrospectively analyzed. Patients were stratified based on the addition of adjuvant RT. Data on overall survival (OS) and local recurrence-free survival (LRFS) were estimated with the Kaplan-Meier method and compared by the log-rank test. RESULTS: A consecutive cohort of 58 male BC patients was evaluated. Median follow-up was 56 months. Twenty-one patients (36.2%) received adjuvant RT. Overall, patients undergoing postoperative RT were characterized by more high-risk features. Patients receiving postoperative RT had significantly more frequently a high UICC stage (50 vs. 9.7% UICC III, p = 0.018) and positive lymph nodes as compared to patients undergoing surgery alone (65 vs. 34.4% pN+, p = 0.046). Accordingly, there was a higher proportion of patients receiving axillary lymph node dissection in the RT group (71.4 vs. 35.6%). Mastectomy was performed in 31/37 (86.1%) in the surgery group as compared to 14/21 (66.7%) in patients receiving postoperative RT. In addition, RT patients were more likely to receive endocrine therapy (78.9 vs. 39.3%, p = 0.016). Outcome was not significantly different between the groups (5-year LRFS: 89.8 vs. 80.0%, p = 0.471 and 5­year OS 88.4 vs. 88.9%, p = 0.819). CONCLUSION: The present observational study evaluated the pattern of care in male BC patients treated in clinical practice. Due to its rarity, randomized clinical trials are unlikely and male BC remains an entity with a poor evidence base. Nevertheless, RT remains a crucial component of the multidisciplinary treatment strategy in male BC.

Tumour-infiltrating lymphocytes and prognosis in different subtypes of breast cancer: a pooled analysis of 3771 patients treated with neoadjuvant therapy.

BACKGROUND: Tumour-infiltrating lymphocytes (TILs) are predictive for response to neoadjuvant chemotherapy in triple-negative breast cancer (TNBC) and HER2-positive breast cancer, but their role in luminal breast cancer and the effect of TILs on prognosis in all subtypes is less clear. Here, we assessed the relevance of TILs for chemotherapy response and prognosis in patients with TNBC, HER2-positive breast cancer, and luminal-HER2-negative breast cancer. METHODS: Patients with primary breast cancer who were treated with neoadjuvant combination chemotherapy were included from six randomised trials done by the German Breast Cancer Group. Pretherapeutic core biopsies from 3771 patients included in these studies were assessed for the number of stromal TILs by standardised methods according to the guidelines of the International TIL working group. TILs were analysed both as a continuous parameter and in three predefined groups of low (0-10% immune cells in stromal tissue within the tumour), intermediate (11-59%), and high TILs (≥60%). We used these data in univariable and multivariable statistical models to assess the association between TIL concentration and pathological complete response in all patients, and between the amount of TILs and disease-free survival and overall survival in 2560 patients from five of the six clinical trial cohorts. FINDINGS: In the luminal-HER2-negative breast cancer subtype, a pathological complete response (pCR) was achieved in 45 (6%) of 759 patients with low TILs, 48 (11%) of 435 with intermediate TILs, and 49 (28%) of 172 with high TILs. In the HER2-positive subtype, pCR was observed in 194 (32%) of 605 patients with low TILs, 198 (39%) of 512 with intermediate TILs, and 127 (48%) of 262 with high TILs. Finally, in the TNBC subtype, pCR was achieved in 80 (31%) of 260 patients with low TILs, 117 (31%) of 373 with intermediate TILs, and 136 (50%) of 273 with high TILs (p<0·0001 for each subtype, χ2 test for trend). In the univariable analysis, a 10% increase in TILs was associated with longer disease-free survival in TNBC (hazard ratio [HR] 0·93 [95% CI 0·87-0·98], p=0·011) and HER2-positive breast cancer (0·94 [0·89-0·99], p=0·017), but not in luminal-HER2-negative tumours (1·02 [0·96-1·09], p=0·46). The increase in TILs was also associated with longer overall survival in TNBC (0·92 [0·86-0·99], p=0·032), but had no association in HER2-positive breast cancer (0·94 [0·86-1·02], p=0·11), and was associated with shorter overall survival in luminal-HER2-negative tumours (1·10 [1·02-1·19], p=0·011). INTERPRETATION: Increased TIL concentration predicted response to neoadjuvant chemotherapy in all molecular subtypes assessed, and was also associated with a survival benefit in HER2-positive breast cancer and TNBC. By contrast, increased TILs were an adverse prognostic factor for survival in luminal-HER2-negative breast cancer, suggesting a different biology of the immunological infiltrate in this subtype. Our data support the hypothesis that breast cancer is immunogenic and might be targetable by immune-modulating therapies. In light of the results in luminal breast cancer, further research investigating the interaction of the immune system with different types of endocrine therapy is warranted. FUNDING: Deutsche Krebshilfe and European Commission.

Outcome after neoadjuvant chemotherapy in estrogen receptor-positive and progesterone receptor-negative breast cancer patients: a pooled analysis of individual patient data from ten prospectively randomized controlled neoadjuvant trials.

PURPOSE: The estrogen receptor (ER) is involved in control of progesterone receptor (PgR) expression and lack of PgR may be also a surrogate of altered growth factor signaling. The aim of this study was therefore to investigate PgR expression as predictive factor for response to neoadjuvant therapy and long-term outcome. METHODS: Five thousand and six hundred and thirteen patients with primary breast cancer and positive ER expression from ten German neoadjuvant trials of anthracycline and taxane-based chemotherapy were included. Pathologic complete response (pCR), disease-free survival (DFS), distant disease-free survival (DDFS), overall survival (OS), and local recurrence-free survival (LRFS) were compared according to PgR expression. RESULTS: The lack of PgR expression (1172 patients) was associated with grade 3 (38.4 vs. 26.3%; p < 0.001), nodal involvement (>cN2) (6.8% vs. 4.7%; p = 0.004), and HER2 positivity (36.2 vs. 22.3%; p < 0.001). pCR rates of PgR-negative tumors were higher in the entire cohort (13.8 vs. 7.5%; p < 0.001) and in the HER2-negative subgroup (11.2 vs. 5.8%; p < 0.001). In multivariable logistic regression, PgR negativity was an independent predictive factor for pCR overall (OR 1.76; p < 0.001) and in the HER2-negative patients (OR 1.99; p < 0.001). Patients with PgR-negative disease had significantly worse outcome (p < 0.001, respectively). Multivariable Cox regression analysis revealed that PgR was an independent prognostic factor for DFS, OS, DDFS, and LRFS. CONCLUSION: ER-positive/PgR-negative breast carcinomas are associated with higher response but also worse long-term outcome after neoadjuvant therapy. PgR negativity is an independent predictive factor for pCR after neoadjuvant chemotherapy in ER-positive HER2-negative breast cancer.

Efficacy and safety of nab-paclitaxel 125 mg/m2 and nab-paclitaxel 150 mg/m2 compared to paclitaxel in early high-risk breast cancer. Results from the neoadjuvant randomized GeparSepto study (GBG 69).

PURPOSE: The GeparSepto study demonstrated that the use of nab-paclitaxel instead of paclitaxel prior to anthracycline-based chemotherapy could lead to a significantly increased pCR rate, especially in the triple negative subpopulation. We report efficacy and safety for patients treated with two different doses of nab-paclitaxel in comparison to weekly solvent-formulated paclitaxel. METHODS: Patients were treated for 12 weeks with either intravenous nab-paclitaxel 150 mg/m2 (nP150) weekly, after study amendment 125 mg/m2 (nP125) weekly or solvent-based paclitaxel 80 mg/m2 (P80) weekly followed by epirubicin 90 mg/m2 and cyclophosphamide 600 mg/m2 on day 1 for four 3-week cycles. RESULTS: 229 patients received nP150, 377 nP125. Baseline characteristics were fairly balanced between these two sequential cohorts as well as compared to 601 patients receiving P80 except for hormone receptor status, HER2 status, and Ki67. Taxane treatment was discontinued in 26.8% (nP150), 16.6% (nP125), and 13.3% of (P80) patients, respectively. Median relative total dose intensity (mRTDI) based on 125 mg/m2 for nP was 103% with nP150, 95% with nP125, 99% with P80 before and 98% with P80 after the amendment. PSN grade 3-4 was observed in 14.5% of patients with nP150, 8.1% of patients with nP125 (p = 0.018), and 2.7% of patients with P80. Overall pCR before the amendment was 33.6% after nP150 and 23.5% after P80 (OR 1.65 [95% CI 1.10-2.50]; p = 0.022); pCR after the amendment was 41.4% after nP125, and 32.4% after P80 (1.48 [95% CI 1.10-1.99]; p = 0.013). CONCLUSIONS: Nab-paclitaxel 125 mg/m2 was associated with a better safety profile and compliance without compromising the efficacy compared to nab-paclitaxel 150 mg/m2.

Nab-paclitaxel versus solvent-based paclitaxel in neoadjuvant chemotherapy for early breast cancer (GeparSepto-GBG 69): a randomised, phase 3 trial.

BACKGROUND: In metastatic breast cancer, nab-paclitaxel has been shown to significantly increase progression-free survival compared with solvent-based paclitaxel. The GeparSepto (GBG 69) trial assessed whether weekly nab-paclitaxel could increase the proportion of patients achieving pathological complete response compared with weekly solvent-based paclitaxel, both followed by epirubicin plus cyclophosphamide as neoadjuvant treatment. METHOD: In a phase 3 randomised trial, we enrolled patients with previously untreated unilateral or bilateral primary invasive breast cancer and randomly assigned them in a 1:1 ratio using dynamic allocation and Pocock minimisation by breast cancer subtype, Ki67 and SPARC expression. Patients were treated for 12 weeks with either intravenous nab-paclitaxel 150 mg/m(2) (after study amendment, 125 mg/m(2)) on days 1, 8, and 15 for four 3-week cycles, or solvent-based intravenous paclitaxel 80 mg/m(2) on days 1, 8, and 15 for four 3-week cycles. Taxane treatment was followed in both groups by intravenous epirubicin 90 mg/m(2) plus intravenous cyclophosphamide 600 mg/m(2) on day 1 for four 3-week cycles. Patients with HER2-positive tumours received concurrent trastuzumab 6 mg/kg (loading dose 8 mg/kg) and pertuzumab 420 mg (loading dose 840 mg) on day 1 of every 3-week cycle. Trastuzumab and pertuzumab were given every 3 weeks concomitantly with chemotherapy for all cycles. This report is the final analysis of the primary endpoint, pathological complete response (ypT0 ypN0), analysed for all patients who started treatment (modified intention to treat). We used a closed test procedure to test for non-inferiority, with the nab-paclitaxel group calculated as non-inferior to the solvent-based paclitaxel group if the lower 95% CI for the OR was above 0·858 (OR equivalent to pathological complete response [33%] minus a 10% non-inferiority margin [3·3%]; 29·7%). We planned to test for superiority only in case of a positive non-inferiority test, using an α of 0·05. Safety was assessed in all patients who received study drug. The trial is registered with ClinicalTrials.gov, number NCT01583426. FINDINGS: Between July 30, 2012, and Dec 23, 2013, we randomly assigned 1229 women, of whom 1206 started treatment (606 with nab-paclitaxel and 600 with solvent-based paclitaxel). The nab-paclitaxel dose was reduced after enrolment of 464 participants to 125 mg/m(2) due to increased treatment discontinuation and sensory neuropathy in this group. Pathological complete response occurred more frequently in the nab-paclitaxel group (233 [38%, 95% CI 35-42] patients) than in the solvent-based paclitaxel group (174 [29%, 25-33] patients; OR 1·53, 95% CI 1·20-1·95; unadjusted p=0·00065). The incidence of grade 3-4 anaemia (13 [2%] of 605 patients in the nab-paclitaxel group vs four [1%] of patients in the solvent-based paclitaxel group; p=0·048) and peripheral sensory neuropathy grade 3-4 (63 [10%] patients receiving any nab-paclitaxel dose; 31 [8%] of patients starting with 125 mg/m(2) and 32 [15%] of patients starting with 150 mg/m(2); vs 16 [3%] in the solvent-based paclitaxel group, p<0·001) was significantly higher for nab-paclitaxel than for solvent-based paclitaxel. Overall, 283 (23%) patients were noted to have at least one serious adverse event (based on study drug received), 156 (26%) in the nab-paclitaxel group and 127 (21%) in the solvent-based paclitaxel group (p=0·057). There were three deaths (during epirubicin plus cyclophosphamide treatment) in the nab-paclitaxel group (due to sepsis, diarrhoea, and accident unrelated to the trial) versus one in the solvent-based paclitaxel group (during paclitaxel treatment; cardiac failure). INTERPRETATION: Substituting solvent-based paclitaxel with nab-paclitaxel significantly increases the proportion of patients achieving a pathological complete response rate after anthracycline-based chemotherapy. These results might lead to an exchange of the preferred taxane, solvent-based paclitaxel, for nab-paclitaxel in therapy for primary breast cancer. FUNDING: Celgene, Roche.

Genetic variants in VEGF pathway genes in neoadjuvant breast cancer patients receiving bevacizumab: Results from the randomized phase III GeparQuinto study.

Studies assessing the effect of bevacizumab (BEV) on breast cancer (BC) outcome have shown different effects on progression-free and overall survival, suggesting that a subgroup of patients may benefit from this treatment. Unfortunately, no biomarkers exist to identify these patients. Here, we investigate whether single nucleotide polymorphisms (SNPs) in VEGF pathway genes correlate with pathological complete response (pCR) in the neoadjuvant GeparQuinto trial. HER2-negative patients were randomized into treatment arms receiving either BEV combined with standard chemotherapy or chemotherapy alone. In a pre-planned biomarker study, DNA was collected from 729 and 724 patients, respectively from both treatment arms, and genotyped for 125 SNPs. Logistic regression assessed interaction between individual SNPs and both treatment arms to predict pCR. Five SNPs may be associated with a better response to BEV, but none of them remained significant after correction for multiple testing. The two SNPs most strongly associated, rs833058 and rs699947, were located upstream of the VEGF-A promoter. Odds ratios for the homozygous common, heterozygous and homozygous rare rs833058 genotypes were 2.36 (95% CI, 1.49-3.75), 1.20 (95% CI, 0.88-1.64) and 0.61 (95% CI, 0.34-1.12). Notably, some SNPs in VEGF-A exhibited a more pronounced effect in the triple-negative subgroup. Several SNPs in VEGF-A may be associated with improved pCR when receiving BEV in the neoadjuvant setting. Although none of the observed effects survived correction for multiple testing, our observations are consistent with previous studies on BEV efficacy in BC. Further research is warranted to clarify the predictive value of these markers.

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.).

Outcome after neoadjuvant chemotherapy in young breast cancer patients: a pooled analysis of individual patient data from eight prospectively randomized controlled trials.

Young women with breast cancer (BC) have a worse survival partly due to more aggressive tumor characteristics; however, their response to chemotherapy seems better. We investigated to what extent the prognostic factor pathological complete remission (pCR) after neoadjuvant chemotherapy is applicable to young women. 8949 patients with primary BC and follow-up from eight German neoadjuvant trials were included. A subgroup of 1453 patients <40 years was compared with women aged 40-49 and ≥50 years regarding pCR (ypT0 ypN0), as well as disease free survival (DFS), local recurrence free survival (LRFS), distant disease free survival (DDFS), and overall survival (OS) overall, according to pCR status and subtypes defined by hormone-receptor (HR) status and HER2. pCR was strongly associated with age without a clear age cut-off. The pCR rate was significantly higher in the young compared with other age groups (20.9 vs. 17.7 vs. 13.7 %; p < 0.001). This difference was confined to triple-negative breast cancer (TNBC) and HR +/HER2-. DFS, DDFS, LRFS, and OS were significantly worse for young women. Age was independently prognostic for survival in HR +/HER2-, with women <40 years without pCR having a worse DFS compared to their counterparts with pCR. Young women are more likely to achieve pCR after neoadjuvant chemotherapy, especially in HR +/HER2- and TNBC. Age is not an important prognostic factor in TNBC and HR-/HER2 + but is in HR +/HER2-. Young women with a luminal-like BC seem to benefit more from neoadjuvant chemotherapy than older women, which needs to be taken into account.

Impact of body mass index on neoadjuvant treatment outcome: a pooled analysis of eight prospective neoadjuvant breast cancer trials.

Obesity is associated with an increased risk of breast cancer (BC) and poorer outcome. We assessed the impact of body mass index (BMI) on pathological complete response (pCR), disease-free (DFS), and overall survival (OS), according to BC subtypes in patients with primary BC treated with neoadjuvant chemotherapy. 8,872 patients with primary BC from eight neoadjuvant trials were categorized according to BMI: underweight (<18.5 kg/m(2)), normal weight (18.5 to <25 kg/m(2)), overweight (25 to <30 kg/m(2)), obese (30 to <40 kg/m(2)), and very obese (≥40 kg/m(2)). BC subtypes were defined as luminal-like (ER/PgR-positive and HER2-negative), HER2/luminal (ER/PgR-positive and HER2-positive), HER2-like (ER/PgR-negative and HER2-positive), and triple-negative (TNBC; ER/PgR- and HER2-negative). pCR rate was higher in normal weight patients compared with all other BMI groups (P = 0.003). Mean DFS and OS were shorter in obese (87.3 months, P = 0.014 and 94.9 months, P = 0.001, respectively) and very obese (66.6 months, P < 0.001 and 75.3 months, P < 0.001, respectively) compared with normal weight patients (91.5 and 98.8 months, respectively) which was confirmed by subpopulation treatment effect pattern plot analyses and was consistent in luminal-like and TNBC. No interaction was observed between BMI and pCR. Normal weight patients experienced less non-hematological adverse events (P = 0.002) and were more likely to receive full taxane doses (P < 0.001) compared with all other BMI groups. In multivariable analysis, the dose of taxanes was predictive for pCR (P < 0.001). Higher BMI was associated with lower pCR and a detrimental impact on survival. Normal weight patients had the best compliance to chemotherapy and received the highest taxane doses, which seems to be related with treatment outcomes.

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.

Response and prognosis after neoadjuvant chemotherapy in 1,051 patients with infiltrating lobular breast carcinoma.

Invasive lobular carcinomas (ILC) show better clinical behaviour compared with other histological types, but significantly lower pathological complete response (pCR) rates after neoadjuvant chemotherapy (NACT). We investigated whether factors influencing pCR rate in ILC after NACT can be identified and whether clinical outcome is different. 9,020 breast cancer patients from nine German neoadjuvant trials with known histological type were pooled. 11.7 % of tumours were ILC. Endpoints were: pCR rate, surgery type and survival. ILC was associated with older age, larger tumour size, lymph node negativity, lower grade and positive hormone-receptor-status (HR). Patients with ILC achieved a significantly lower pCR rate compared with non-ILC patients (6.2 vs. 17.4 %, P < 0.001). The pCR rate was 4.2 % in ILC/HR+/G1-2, 7.0 % in ILC with either HR- or G3, and 17.8 % in ILC/HR-/G3. Mastectomy rate was higher in ILC compared with non-ILC patients irrespective of response to NACT (pCR: 27.4 vs. 16.6 %, P = 0.037 and non-pCR: 41.8 % vs. 31.5 %, P < 0.0001). Age and HR independently predicted pCR in ILC. In ILC patients, pCR did not predict distant disease free (DDFS) and loco-regional disease free survival (LRFS), but overall survival (OS). Non-pCR patients with ILC had significantly better DDFS (P = 0.018), LRFS (P < 0.0001) and OS (P = 0.044) compared with non-ILC patients. Patients with ILC had a low chance of obtaining a pCR and this is not well correlated with further outcome. The mastectomy rate was considerably high in ILC patients even after obtaining a pCR. We, therefore, suggest to offer NACT mainly to ILC patients with HR-negative tumours.

Surgical outcome after neoadjuvant chemotherapy and bevacizumab: results from the GeparQuinto study (GBG 44).

PURPOSE: Bevacizumab, 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. METHODS: In the GeparQuinto trial, 1,948 patients were randomized to receive four cycles epirubicin/cyclophosphamide (EC, 90/600 mg/m(2) q3w) followed by four cycles docetaxel (D, 100 mg/m(2) q3w) each with (ECB-DB) or without (EC-D) bevacizumab (B, 15 mg/kg q3w) concurrent with chemotherapy. Surgery had to be performed not earlier than 28 days after the last bevacizumab infusion, but within days 21 and 35 after the last chemotherapy. RESULTS: In 743 (38.1 %) 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 (N = 502) was 69.1 % (EC-D) and 71.9 % (ECB-DB; p = 0.464). The first surgical procedure was performed at a median of 29 (EC-D) and 34 days (ECB-DB) after last chemotherapy with or without bevacizumab infusion (p < 0.001). Surgical complications were documented in 38 (10.9 %; EC-D) and 59 (15.0 %; ECB-DB) patients (p = 0.103). Surgical complications were significantly higher after ECD-DB only in patients treated with BCS (N = 53; p = 0.029) or in those requiring repeat surgery in order achieve clear margins (N = 23; p = 0.037) compared to the EC-D group. CONCLUSIONS: Addition of bevacizumab to neoadjuvant chemotherapy might be associated with an increased risk for surgical complications in patients treated with BCS or after repeated surgeries.

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.

Identifying breast cancer patients at risk of relapse despite pathological complete response after neoadjuvant therapy.

This retrospective pooled analysis aims to identify factors predicting relapse despite a pathologic complete response (pCR) in patients with breast cancer (BC). 2066 patients with a pCR from five neoadjuvant GBG/AGO-B trials fulfill the inclusion criteria of this analysis. Primary endpoint is disease-free survival (DFS); secondary endpoints is distant DFS (DDFS) and overall survival (OS). After a median follow-up of 57.6 months, DFS is significantly worse for patients with positive lymph nodes (cN+ vs cN0 hazard ratio [HR] 1.94, 95%CI 1.48-2.54; p < 0.001). In patients with triple-negative tumors, lobular histology (lobular vs other HR 3.55, 95%CI 1.53-8.23; p = 0.003), and clinical nodal involvement (cN+ vs cN0 HR 2.45, 95%CI 1.59-3.79; p < 0.001) predict a higher risk of DFS events. Patients with HER2-positive cT3/4 tumors have a significantly higher risk of relapse (cT3/4 vs cT1 HR 2.07, 95%CI 1.06-4.03; p = 0.033). Initial tumor load and histological type predict relapse in patients with a pCR.

RANK Expression as an Independent Predictor for Response to Neoadjuvant Chemotherapy in Luminal-Like Breast Cancer: A Translational Insight from the GeparX Trial.

PURPOSE: The GeparX study investigated whether denosumab as add-on treatment to nab-paclitaxel-based neoadjuvant chemotherapy (NACT) with two different schedules (125 mg/m² weekly vs. day 1, 8 every 22 days) may increase pathologic complete response (pCR) rate. The addition of denosumab to NACT did not improve pCR rates as recently published. In this study, we investigated whether receptor activator of nuclear factor-kappa B (RANK) expression, as part of the denosumab target pathway: (i) may retrospectively identify a subgroup of patients with additional clinical benefit of denosumab or (ii) may predict response to nab-paclitaxel NACT. EXPERIMENTAL DESIGN: RANK protein was IHC-stained on pre-therapeutic core biopsies from patients of the GeparX study (n = 667) with the antibody RANK/Envision System HRP (DAB) and was analyzed for the percentage of membranous RANK tumor cell staining (>5% RANKhigh vs. ≤5% RANKlow). RESULTS: We could not identify any patient subgroup with differential response under denosumab add-on treatment in patients with RANKhigh expression [139/667, 20.8%; OR, 0.86; 95% confidence interval (CI), 0.44-1.68; P = 0.667] or RANKlow expression (528/667 (79.2%) OR, 1.10; 95% CI, 0.78-1.56; P = 0.589; Pinteraction = 0.528). However, the pCR rate was higher in the RANKhigh subgroup compared with RANKlow (50% vs. 39%; OR, 1.52; 95% CI, 1.04-2.21; P = 0.037). RANK expression constituted an independent predictor of response to NACT frequently in patients with luminal-like subtype (HR+/HER2-; OR, 2.98; 95% CI, 1.30-6.79; P = 0.010). No predictive value of RANK expression among the different nab-paclitaxel regimens was observed. CONCLUSION: We report RANK expression to be an independent predictive biomarker for response to NACT in patients with luminal-like breast cancer.

Responsiveness of adjacent ductal carcinoma in situ and changes in HER2 status after neoadjuvant chemotherapy/trastuzumab treatment in early breast cancer--results from the GeparQuattro study (GBG 40).

Adjacent ductal carcinoma in situ (DCIS) is found in approximately 45% of invasive ductal carcinomas (IDC) of the breast. Pure DCIS overexpresses HER2 in approximately 45%. There is uncertainty whether adjacent DCIS impacts on the response to neoadjuvant chemotherapy and trastuzumab as well as whether HER2 expression in IDC component or adjacent DCIS changes throughout treatment. Core biopsies and surgical tissue from participants of the GeparQuattro study with HER2-positive IDC were centrally examined for the area of invasive ductal component and adjacent DCIS before and after receiving neoadjuvant anthracycline-taxane-trastuzumab containing chemotherapy. HER2 overexpression in IDC and adjacent DCIS was quantified separately by immunohistochemistry using the Ventana automated staining system. Pathological complete response (pCR) was defined as no residual invasive or non-invasive tumor tissue. Fifty-nine (37.3%) of 158 IDCs presented with adjacent DCIS at diagnosis. These tumors showed lower regression grades than pure IDC (P = 0.033). The presence of adjacent DCIS was an independent negative predictor of pCR [odds ratio 0.42 (95% CI 0.2-0.9), P = 0.027]. Adjacent DCIS area decreased from pre-treatment to surgery (r = 0.205) with 30 (50.8%) IDCs with adjacent DCIS showing complete eradication of adjacent DCIS. HER2 status of adjacent DCIS was highly correlated with HER2 status of IDC component before (r = 0.892) and after treatment (r = 0.676). Degree of HER2 overexpression of the IDC component decreased in 16 (33.3%) out of 49 patients without a pCR. These 16 IDCs showed lower RGs compared to the 33 IDCs with unchanged HER2 expression (P = 0.055). HER2-positive IDCs with adjacent DCIS is less responsive to neoadjuvant chemotherapy and trastuzumab compared to pure IDC. However, complete eradication of adjacent DCIS is frequently observed. HER2-overexpression of the invasive ductal component decreases in a subset of tumors, which showed less tumor regression.

Validation of the 21-Gene Recurrence Score Assay in Patients with Hormone Receptor-Positive, HER2-Negative Breast Cancer and 0 to 3 Positive Lymph Nodes: Risk Pattern and Outcomes on a Community Level.

Introduction: The aim of the present study was to analyze the performance of Oncotype DX® multigene assay (ODX®) in patients with 0-3 lymph nodes in a high-volume community hospital. Methods: Patients with non-metastatic HR*/HER2- EBC and 0-3 positive lymph nodes, who underwent primary surgery at the Red Cross Hospital Munich, Germany and consecutively had ODX® testing were included in this retrospective study. The distribution of clinicopathologic characteristics, recurrence score (RS) risk, and use of systemic therapy were compared among patients without positive lymph nodes (N0) and patients with micrometastases or 1 to 3 positive lymph nodes (N1). Disease-free survival (DFS) and overall survival (OS) were estimated. Results: From 2012 to 2017 ODX® was consecutively performed in 575 (16.4%) of 3,492 women with HR*/HER- EBC, of which 553 were eligible for this analysis (N0: 60.8%; N1: 39.2%). Among the patients included, 441 (79.7%) had an RS of 0 to 25 and 112 (20.3%) had an RS of 26 or higher. In patients with RS 0 to 25 the rate of chemotherapy use was low, independent from nodal status (N0: 17.1% and N1: 19.1%) and 5-year DFS was 90.5% and 91.7% for N0 and N1 patients, respectively. There was no significant difference in DFS (90.5% vs. 93.3%; p = 0.101) or OS (97.2% vs. 96.0%; p = 0.737) for patients with an RS of 0 to 25 when treated with chemo-endocrine therapy or endocrine therapy alone, independent from nodal status. Conclusions: The results of the study confirm the observations from randomized studies on the use of the ODX® in a real-world population in terms of risk distribution and patient outcome. Adjuvant chemotherapy could be safely omitted in patients with HR*/HER2- breast cancer with 0-3 positive lymph nodes and RS <25.