Randomised phase III trial of FEC120 vs EC-docetaxel in patients with high-risk node-positive primary breast cancer: final survival analysis of the ADEBAR study.

BACKGROUND: Taxane-containing adjuvant chemotherapy has been established as standard treatment in node-positive breast cancer. This study compared efficacy and tolerability of epirubicin (E)/cyclophosphamide (C) followed by docetaxel (Doc) with a dose-dense 5-fluorouracil (F)+E+ C regimen. METHODS: The ADEBAR study was a randomised phase III trial for women with primary invasive breast cancer and ⩾4 metastatic axillary lymph nodes (n=1364). Treatment consisted of four 21-day cycles of E plus C, followed by four 21-day cycles of Doc (EC-Doc), or six 28-day cycles of E plus F plus C (FEC120). RESULTS: Disease-free survival (DFS) was similar in the two treatment arms as shown by multivariate Cox regression adjusted for other prognostic factors (EC-Doc vs FEC120, hazard ratio (HR): 1.087; 95% confidence interval (CI): 0.878-1.346, P=0.444). In addition, there was no significant difference in overall survival (OS) between the two groups (HR: 0.974; 95% CI: 0.750-1.264, P=0.841). Haematologic toxicity was more common in FEC120 recipients; non-haematologic toxicities occurred more frequently in the EC-Doc arm. The serious adverse event rate was significantly higher in the FEC120 group (29.7% vs 22.5%). CONCLUSIONS: EC-Doc provides a feasible and effective alternative therapy option to FEC120 with a different safety profile in this high-risk breast cancer cohort.

Comparison of prognostic and predictive impact of genomic or central grade and immunohistochemical subtypes or IHC4 in HR+/HER2- early breast cancer: WSG-AGO EC-Doc Trial.

INTRODUCTION: Potential prognostic and predictive markers in early, intermediate-risk breast cancer (BC) include histological grade, Ki-67, genomic signatures, e.g. genomic grade index (GGI), and intrinsic subtypes. Their prognostic/predictive impact in hormone receptor (HR: ER and/or PR) positive/HER2- BC is controversial. WSG-AGO EC-Doc demonstrated superior event-free survival (EFS) in patients with 1-3 positive lymph node receiving epirubicin/cyclophosphamide-docetaxel (EC-Doc) versus 5-fluoruracil/epirubicin/cyclophosphamide (FEC). METHODS: In a representative trial subset, we quantify concordance among factors used for clinical chemotherapy indication. We investigate the impact of central histology (n = 772), immunohistochemistry for intrinsic subtyping and IHC4, and dichotomous (GG) or continuous (GGI) genomic grade (n = 472) on patient outcome and benefit from taxane chemotherapy, focusing on HR+/HER2- patients (n = 459). RESULTS: Concordance of local grade (LG) with central (CG) or genomic grade was modest. In HR+/HER2- patients, low (GG-1: 16%), equivocal (GG-EQ: 17%), and high (GG-3: 67%) GG were associated with respective 5-year EFS of 100%, 93%, and 85%. GGI was prognostic for EFS within all LG subgroups and within CG3, whereas IHC4 was prognostic only in CG3 tumors.In unselected and HR+/HER2- patients, CG3 and luminal-A-like subtype entered the multivariate EFS model, but not IHC4 or GG. In the whole population, continuous GGI entered the model [hazard ratio (H.R.) of 75th versus 25th = 2.79; P = 0.01], displacing luminal-A-like subtype; within HR+/HER2- (H.R. = 5.36; P < 0.001), GGI was the only remaining prognostic factor.In multivariate interaction analysis (including central and genomic grade), luminal-B-like subtype [HR+ and (Ki-67 ≥20% or HER2+)] was predictive for benefit of EC-Doc versus FEC in unselected but not in HR+/HER2- patients. CONCLUSION: In the WSG-AGO EC-Doc trial for intermediate-risk BC, CG, intrinsic subtype (by IHC), and GG provide prognostic information. Continuous GGI (but not IHC4) adds prognostic information even when IHC subtype and CG are available. Finally, the high interobserver variability for histological grade and the still missing validation of Ki-67 preclude indicating or omitting adjuvant chemotherapy based on these single factors alone. TRIAL REGISTRATION: The WSG-AGO/EC-Doc is registered at ClinicalTrials.gov, NCT02115204.

Final analysis of the prospective WSG-AGO EC-Doc versus FEC phase III trial in intermediate-risk (pN1) early breast cancer: efficacy and predictive value of Ki67 expression.

BACKGROUND: Taxane-based adjuvant chemotherapy is standard in node-positive (N+) early breast cancer (BC). The magnitude of benefit in intermediate-risk N+ early BC is still unclear. WSG-AGO epiribicine and cyclophosphamide (EC)-Doc is a large trial evaluating modern taxane-based chemotherapy in patients with 1-3 positive lymph nodes (LNs) only. PATIENTS AND METHODS: A total of 2011 BC patients (18-65 years, pN1) were entered into a randomized phase III trial comparing 4 × E90C600 q3w followed by 4 × docetaxel 100 q3w (n = 1008) with the current standard: 6 × F500E100C500 q3w (n = 828) or C600M40F600 d1, 8× q4w (n = 175). Primary end point was event-free survival (EFS); secondary end points were overall survival (OS), toxicity, translational research, and quality of life. Central tumor bank samples were evaluable in a representative collective (n = 772; 40%). Ki-67 was assessed centrally in hormone receptor-positive disease as a surrogate marker for the distinction of luminal A/B-like tumors. RESULTS: Baseline characteristics were well balanced between study arms in both main study and central tumor bank subset. At 59-month median follow-up, superior efficacy of EC-Doc [versus FEC (a combination of 5-fluorouracil, epirubicin, and cyclophosphamide)] was seen in EFS and OS: 5-year EFS: 89.8% versus 87.3% (P = 0.038); 5-year OS: 94.5% versus 92.8% (P = 0.034); both tests one-tailed. EC-Doc caused more toxicity. In hormone receptor-positive (HR)+ disease, only high-Ki-67 tumors (≥ 20%) derived significant benefit from taxane-based therapy: hazard ratio = 0.39 (95% CI 0.18-0.82) for EC-Doc versus FEC (test for interaction; P = 0.01). CONCLUSION: EC-Doc significantly improved EFS and OS versus FEC in intermediate-risk BC (1-3 LNs) within all subgroups as defined by local pathology. In HR+ disease, patients with luminal A-like tumors may be potentially over-treated by taxane-based chemotherapy. CLINICAL TRIAL NUMBER: ClinicalTrials.gov, NCT02115204.

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.

Bone mineral density in breast cancer patients treated with adjuvant letrozole, tamoxifen, or sequences of letrozole and tamoxifen in the BIG 1-98 study (SAKK 21/07).

BACKGROUND: The risk of osteoporosis and fracture influences the selection of adjuvant endocrine therapy. We analyzed bone mineral density (BMD) in Swiss patients of the Breast International Group (BIG) 1-98 trial [treatment arms: A, tamoxifen (T) for 5 years; B, letrozole (L) for 5 years; C, 2 years of T followed by 3 years of L; D, 2 years of L followed by 3 years of T]. PATIENTS AND METHODS: Dual-energy X-ray absorptiometry (DXA) results were retrospectively collected. Patients without DXA served as control group. Repeated measures models using covariance structures allowing for different times between DXA were used to estimate changes in BMD. Prospectively defined covariates were considered as fixed effects in the multivariable models. RESULTS: Two hundred and sixty-one of 546 patients had one or more DXA with 577 lumbar and 550 hip measurements. Weight, height, prior hormone replacement therapy, and hysterectomy were positively correlated with BMD; the correlation was negative for letrozole arms (B/C/D versus A), known osteoporosis, time on trial, age, chemotherapy, and smoking. Treatment did not influence the occurrence of osteoporosis (T score < -2.5 standard deviation). CONCLUSIONS: All aromatase inhibitor regimens reduced BMD. The sequential schedules were as detrimental for bone density as L monotherapy.