SNP of Aromatase Predict Long-term Survival and Aromatase Inhibitor Toxicity in Patients with Early Breast Cancer: A Biomarker Analysis of the GIM4 and GIM5 Trials.

PURPOSE: In estrogen receptor-positive (ER+) breast cancer, single-nucleotide polymorphisms (SNP) in the aromatase gene might affect aromatase inhibitors (AI) metabolism and efficacy. Here, we assessed the impact of SNP on prognosis and toxicity of patients receiving adjuvant letrozole. EXPERIMENTAL DESIGN: We enrolled 886 postmenopausal patients in the study. They were treated with letrozole for 2 to 5 years after taking tamoxifen for 2 to 6 years, continuing until they completed 5 to 10 years of therapy. Germline DNA was genotyped for SNP rs4646, rs10046, rs749292, and rs727479. Log-rank test and Cox model were used for disease-free survival (DFS) and overall survival (OS). Cumulative incidence (CI) of breast cancer metastasis was assessed through competing risk analysis, with contralateral breast cancer, second malignancies and non-breast cancer death as competing events. CI of skeletal and cardiovascular events were assessed using DFS events as competing events. Subdistribution HR (sHR) with 95% confidence intervals were calculated through Fine-Gray method. RESULTS: No SNP was associated with DFS. Variants rs10046 [sHR 2.03, (1.04-2.94)], rs749292 [sHR 2.11, (1.12-3.94)], and rs727479 [sHR 2.62, (1.17-5.83)] were associated with breast cancer metastasis. Three groups were identified on the basis of the number of these variants (0, 1, >1). Variant-based groups were associated with breast cancer metastasis (10-year CI 2.5%, 7.6%, 10.7%, P = 0.035) and OS (10-year estimates 96.5%, 93.0%, 89.6%, P = 0.030). Co-occurrence of rs10046 and rs749292 was negatively associated with 10-year CI of skeletal events (3.2% vs. 10%, P = 0.033). A similar association emerged between rs727479 and cardiovascular events (0.3% vs. 2.1%, P = 0.026). CONCLUSIONS: SNP of aromatase gene predict risk of metastasis and AI-related toxicity in ER+ early breast cancer, opening an opportunity for better treatment individualization.

Nine-Week Versus One-Year Trastuzumab for Early Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer: 10-Year Update of the ShortHER Phase III Randomized Trial.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned coprimary or secondary analyses are not yet available. Clinical trial updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.We present the final analysis of the phase III noninferiority, randomized ShortHER trial comparing 9 weeks versus 1 year of adjuvant trastuzumab with chemotherapy in patients with human epidermal growth factor receptor 2-positive (HER2+) early breast cancer (BC). Women with HER2+ BC were randomly assigned to anthracycline-taxane combinations plus 1-year trastuzumab (arm A, long) or 9-week trastuzumab (arm B, short). Here, we report the second coprimary end point overall survival (OS), updated disease-free survival (DFS), and outcomes according to hormone receptor status, age, and nodal status. At a median follow-up of 9 years, 10-year DFS is 77% versus 78% in the long versus short arm, respectively. Ten-year OS is 89% versus 88% in the long versus short arm, respectively. 10-year DFS rates in the long versus short arm according to nodal status are N0 81% versus 85%; N1-3 77% versus 79%; and N4+ 63% versus 53%. Ten-year OS rates in long versus short arm according to nodal status are N0 89% versus 95%%; N1-3 92% versus 89%; and N4+ 84% versus 64%. The updated analysis of the ShortHER trial shows that 1-year trastuzumab is the standard treatment for patients with HER2+ early BC as noninferiority cannot be claimed. However, numerically, the differences for the patients at low or intermediate risk (N0/N1-3) is negligible, while patients with N4+ have a clear benefit with 1-year trastuzumab.

Prognostic and clinical impact of the endocrine resistance/sensitivity classification according to international consensus guidelines for advanced breast cancer: an individual patient-level analysis from the Mammella InterGruppo (MIG) and Gruppo Italiano Mammella (GIM) studies.

Background: Prior exposure to adjuvant endocrine therapy (ET) and timing to recurrence are crucial factors for first-line treatment choices in patients with hormone receptor-positive/HER2-negative (HR+/HER2-) breast cancer (BC) and in clinical trial eligibility, classifying metastatic HR+/HER2- BC as endocrine sensitive (ES) or primary (1ER)/secondary (2ER) resistant. However, this classification is largely based on expert opinion and no proper evidence exists to date to support its possible prognostic and clinical impact. Methods: This analysis included individual patient-level data from 4 adjuvant phase III randomized trials by the Mammella InterGruppo (MIG) and Gruppo Italiano Mammella (GIM) study groups. The impact of endocrine resistance/sensitivity classification on overall survival (mOS, defined as time between date of distant relapse and death) was assessed in both univariate and multivariate Cox proportional hazards models. Findings: Between November 1992 and July 2012, 9058 patients were randomized in 4 trials, of whom 6612 had HR+/HER2- BC. Median follow-up was 9.1 years (interquartile range [IQR] 5.6-15.0). In the whole cohort, disease-free survival and OS were 90.4% and 96.6% at 5 years, and 79.1% and 89.4% at 10 years, respectively. The estimated hazard of recurrence raised constantly during the first 15 years from diagnosis, being more pronounced during the first 2 years and less pronounced after year 7. Among the 493 patients with a distant relapse as first disease-free survival event and available date on ET completion, 72 (14.6%), 207 (42.0%) and 214 (43.4%) were classified as having 1ER, 2ER and ES, respectively. Median follow-up from diagnosis of a distant relapse was 3.8 years (IQR 1.6-7.5). Patients with 1ER were significantly more likely to be younger, to have N2/N3 nodal status, grade 3 tumours and to develop visceral metastases. Site of first distant relapse was significantly different between the 3 groups (p = 0.005). In patients with 1ER, 2ER and ES breast cancer, median mOS was 27.2, 38.4 and 43.2 months, respectively (p = 0.03). As compared to patients with ES disease, a higher risk of death was observed in those with 1 ER (adjusted Hazard Ratio [aHR] 1.54; 95% CI 1.03-2.30) and 2ER (aHR 1.17; 95% CI 0.87-1.56) (p = 0.11). Interpretation: This large analysis with long-term follow-up provides evidence on the prognostic and clinical impact of the currently adopted endocrine resistance/sensitivity classification in patients with HR+/HER2- advanced BC. This classification may be considered a valid tool to guide clinical decision-making and to design future ET trials in the metastatic setting. Funding: AIRC.

Clinical Outcomes of HER2-Negative Metastatic Breast Cancer Patients in Italy in the Last Decade: Results of the GIM 13-AMBRA Study.

GIM 13-AMBRA is a longitudinal cohort study aimed at describing therapeutic strategies and the relative outcome parameters in 939 HER2-ve MBC patients. Taxanes-based regimens, or taxanes + targeted agents, mainly Bevacizumab, were the preferred first choice in both Luminal (30.2%) and TNBC (33.3%) patients. The median PFS1 was 12.5 months (95% CI 16.79-19.64), without any significant difference according to subtypes, while the median Time to first Treatment Change (TTC1) was significantly lower in TNBC patients (7.7 months-95% CI 5.7-9.2) in comparison to Luminal A (13.2 months, 95% CI 11.7-15.1) and Luminal B patients (11.8 months, 95% CI 10.3-12.8). PFS2 was significantly shorter in TNBC patients (5.5 months, 95% CI 4.3-6.5 vs. Luminal A-9.4, 95% CI 8.1-10.7, and Luminal B-7.7 95% CI 6.8-8.2, F-Ratio 4.30, p = 0.014). TTC2 was significantly lower in patients with TNBC than in those with the other two subtypes. The median OS1 was 35.2 months (95% CI 30.8-37.4) for Luminal A patients, which was significantly higher than that for both Luminal B (28.9 months, 95% CI 26.2-31.2) and TNBC (18.5 months, 95% CI 16-20.1, F-ratio 7.44, p = 0.0006). The GIM 13-AMBRA study is one of the largest collections ever published in Italy and provides useful results in terms of time outcomes for first, second, and further lines of treatment in HER2- MBC patients.

Fluorouracil and dose-dense adjuvant chemotherapy in patients with early-stage breast cancer (GIM2): end-of-study results from a randomised, phase 3 trial.

BACKGROUND: Previous analyses of the GIM (Gruppo Italiano Mammella) 2 study showed that addition of fluorouracil to epirubicin, cyclophosphamide, and paclitaxel in patients with node-positive early breast cancer does not improve outcome, whereas dose-dense chemotherapy induces a significant improvement in both disease-free survival and overall survival as compared with a standard schedule. Here, we present long-term results of the study. METHODS: In this 2 × 2 factorial, open-label, randomised, phase 3 trial, we enrolled patients aged 18-70 years with operable, node-positive, breast cancer with Eastern Cooperative Oncology Group performance status of 0-1 from 81 hospitals in Italy. Eligible patients were randomly allocated (1:1:1:1) to one of the four following study groups: four cycles of standard-interval intravenous EC (epirubicin 90 mg/m2 and cyclophosphamide 600 mg/m2) on day 1 every 3 weeks, followed by four cycles of intravenous paclitaxel (175 mg/m2) on day 1 every 3 weeks (q3EC-P group); four cycles of intravenous FEC (fluorouracil 600 mg/m2, epirubicin 90 mg/m2, and cyclophosphamide 600 mg/m2) on day 1 every 3 weeks, followed by four cycles of intravenous paclitaxel (175 mg/m2) on day 1 every 3 weeks (q3FEC-P group); dose-dense EC-P regimen, with the same doses and drugs as the q3EC-P group but administered every 2 weeks (q2EC-P group); and the dose-dense FEC-P regimen, with the same doses and drugs as the q3FEC-P group but given every 2 weeks (q2FEC-P). Randomisation, with stratification by centre, with permuted blocks of size 12, was done with a centralised, interactive, internet-based system that randomly generated the treatment allocation. The primary endpoint was disease-free survival in the intention-to-treat population, comparing different chemotherapy schedule (dose-dense vs standard-dose intervals) and regimen (FEC-P vs EC-P). Safety population included all patients that received at least one dose of any study drug according to the treatment received. This trial is registered with ClinicalTrials.gov, NCT00433420, and is now closed. FINDINGS: Between April 24, 2003, and July 3, 2006, 2091 patients were randomly assigned to treatment: 545 to q3EC-P, 544 to q3FEC-P, 502 to q2EC-P, and 500 to q2FEC-P. 88 patients were enrolled in centres providing only standard interval schedule and were assigned only to q3FEC-P and q3EC-P; thus, 2091 patients were included in the intention-to-treat analysis for the comparison of EC-P (1047 patients) versus FEC-P (1044 patients) and 2003 patients were included in the intention-to-treat analysis for the comparison of dose-dense (1002 patients) versus standard interval analysis (1001 patients). After a median follow-up of 15·1 years (IQR 8·4-16·3), median disease-free survival was not significantly different between FEC-P and EC-P groups (17·09 years [95% CI 15·51-not reached] vs not reached [17·54-not reached]; unadjusted hazard ratio 1·12 [95% CI 0·98-1·29]; log-rank p=0·11). Median disease-free survival was significantly higher in the dose-dense interval group than the standard-interval group (not reached [95% CI 17·45-not reached] vs 16·52 [14·24-17·54]; 0·77 [95% CI 0·67-0·89]; p=0·0004). The most common grade 3-4 adverse events were neutropenia (200 [37%] of 536 patients in the q3EC-P group vs 257 [48%] of 533 in the q3FEC-P group vs 50 [10%] of 496 q2EC-P vs 97 [20%] of 492) and alopecia (238 [44%] vs 249 [47%] vs 228 [46%] vs 235 [48%]). During extended follow-up, no further grade 3-4 adverse events or deaths related to toxic-effects were reported. Treatment-related serious adverse events were reported in nine (2%) patients in the q3EC-P group, seven (1%) in the q3FEC-P group, nine (2%) in the q2EC-P group, and nine (2%) in the q2FEC-P group. No treatment-related deaths occurred. INTERPRETATION: Updated results from the GIM2 study support that optimal adjuvant chemotherapy for patients with high-risk early breast cancer should not include fluorouracil and should use a dose-dense schedule. FUNDING: Bristol-Myers Squibb, Pharmacia, Dompè Biotec Italy, Italian Ministry of Health, Fondazione Italiana per la Ricerca sul Cancro, and Alliance Against Cancer.

Composite risk and benefit from adjuvant dose-dense chemotherapy in hormone receptor-positive breast cancer.

The GIM2 phase III trial demonstrated the benefit of dose-dense chemotherapy in node-positive early breast cancer (eBC). To better define the dose-dense effect in the hormone receptor-positive subgroup, we evaluated its benefit through a composite measure of recurrence risk. We conducted an ancillary analysis of the GIM2 trial evaluating the absolute treatment effect through a composite measure of recurrence risk (CPRS) in patients with hormone receptor-positive HER2-negative eBC. CPRS was estimated through Cox proportional hazards models applied to the different clinicopathological features. The treatment effect was compared to the values of CPRS by using the Sub-population Treatment Effect Pattern Plot (STEPP) process. The Disease-Free Survival (DFS)-oriented STEPP analysis showed distinct patterns of relative treatment effect with respect to CPRS. Overall, 5-year DFS differed across CPRS quartiles ranging from 95.2 to 66.4%. Each CPRS quartile was characterized by a different patients' composition, especially for age, lymph node involvement, tumor size, estrogen and progesterone receptor expression, and Ki-67. A number needed to treat of 154 and 6 was associated with the lowest and the highest CPRS quartile, respectively. Dose-dense adjuvant chemotherapy showed a consistent benefit in node-positive eBC patients with hormone receptor-positive HER2-negative disease, but its effect varied according to CPRS.

Is There Still a Role for Endocrine Therapy Alone in HR+/HER2- Advanced Breast Cancer Patients? Results from the Analysis of Two Data Sets of Patients Treated with High-Dose Fulvestrant as First-Line Therapy in the Real-World Setting: The EVA and GIM-13 AMBRA Studies.

BACKGROUND: Different studies suggest that fulvestrant 500 mg every 28 days (HD-FUL) could be an active treatment in HR+ advanced breast cancer (ABC) patients even treated with aromatase inhibitors in the adjuvant setting. The aim of this analysis is to describe the outcome of ABC patients treated with HD-FUL as first-line treatment in terms of median duration of treatment and the overall response rate in a real-world setting. METHODS: For the purpose of the present analysis, we considered two data sets of HR+ ABC patients collected in Italy between 2012 and 2015 (EVA and GIM-13 AMBRA studies). RESULTS: Eighty-one and 91 patients have been identified from the two data sets. The median age was 63 years (range 35-82) for the EVA and 57.8 years (range 35.0-82.3) for the AMBRA patients. ORRs were 23.5 and 24.3% in the whole population, 26.9% in the patients with bone only, and 21.8 and 21.4% in those with visceral metastases. The median duration of HD-FUL was 11.6 months (range 1-48) and 12.4 months (range 2.9-70.0) in the two data sets, respectively. CONCLUSION: These data suggest that HD-FUL should still continue to play a significant role as first-line therapy in HR+ ABC patients.

Dose-dense adjuvant chemotherapy in HER2-positive early breast cancer patients before and after the introduction of trastuzumab: Exploratory analysis of the GIM2 trial.

Dose-dense adjuvant chemotherapy is standard of care in high-risk early breast cancer patients. However, its role in HER2-positive patients is still uncertain. In this exploratory analysis of the GIM2 trial, we investigated the efficacy of dose-dense chemotherapy in HER2-positive breast cancer patients with or without exposure to trastuzumab. In the GIM2 trial, node-positive early breast cancer patients were randomized to receive four cycles of (fluorouracil)epirubicin/cyclophosphamide followed by four cycles of paclitaxel administered every 2 (dose-dense) or 3 (standard-interval) weeks. After approval of adjuvant trastuzumab, protocol was amended in April 2006 to allow use of trastuzumab for 1 year after chemotherapy completion in HER2-positive patients. The efficacy of dose-dense chemotherapy in terms of disease-free survival (DFS) and overall survival (OS) was assessed according to HER2 status and trastuzumab use. Out of 2,003 breast cancer patients, HER2 status was negative/unknown in 1,551 patients; among the 452 patients with HER2-positive breast cancer, chemotherapy alone or followed by trastuzumab was given to 320 and 132 patients, respectively. Median follow-up was 8.1 years. No significant interaction between HER2 status, trastuzumab use and chemotherapy treatment was observed for both DFS (p = 0.698) and OS (p = 0.708). Nevertheless, there was no apparent benefit in the HER2-positive group treated with trastuzumab (DFS: HR, 0.99; 95% CI 0.52-1.89; OS: HR, 0.95; 95% CI 0.37-2.41). Although dose-dense chemotherapy was associated with a significant survival improvement in high-risk breast cancer patients, its benefit appeared to be smaller (if any) in patients with HER2-positive disease who received adjuvant trastuzumab.

Correction: Everolimus (EVE) and exemestane (EXE) in patients with advanced breast cancer aged ≥ 65 years: new lessons for clinical practice from the EVA study.

[This corrects the article DOI: 10.18632/oncotarget.25874.].

Everolimus (EVE) and exemestane (EXE) in patients with advanced breast cancer aged ≥ 65 years: new lessons for clinical practice from the EVA study.

BACKGROUND: The present analysis focuses on real-world data of Everolimus-Exemestane in advanced HR+ve, HER2-ve elderly breast cancer patients (aged 65 years) included in the EVA study, with unique findings in those aged 70 years. METHODS: Data are collected from clinical records and analysed according to age cut-off (< 65 years; 65 - 69 years and {greater than or equal to} 70 years). Relationship of analyzed variables with response were tested by mean of a Mantel-Haenszel chi square test. Time to event analysis was described by Kaplan Meier approach and association with baseline characteristics was analysed by stratified log-rank test and proportional hazard model. RESULTS: From July 2013 to December 2015, the EVA study enrolled overall 404 pts. 154 patients out of 404 (38,1%) were aged {greater than or equal to} 65 years, of whom 87 were {greater than or equal to} 70 years. Median duration of EVE treatment was 28.5 weeks (95% CI 19.0 - 33.8) in patients aged 65-69 years and 24,4 weeks (95% CI 19,2 - 33,2) in those aged {greater than or equal to} 70 years. Fewer patients aged 65 years received the highest EVE Dose-Intensity (>7.5 mg/day) in comparison to younger patients (49,6% vs. 66,8%). Grade 3-4 toxicities occurred to 55 patients (35,7%), mainly stomatitis (10,9%), rash (5,8%) and non-infectious pneumonitis (NIP) (3,6%). Some toxicities, such as weight loss and anaemia were peculiarly observed in patients aged {greater than or equal to} 70 years. Five treatment-related deaths were collected (3,2%). CONCLUSIONS: EVE-EXE combination remains one of the potential treatments in HR+ patients also for elderly ones.

Eribulin Treatment in Patients with Liver Metastatic Breast Cancer: Eight Italian Case Reports.

Liver metastases are very common in metastatic breast cancer (MBC); current treatments for these lesions are based on systemic chemotherapy, endocrine- or human epidermal growth factor receptor 2 (HER2)-targeted therapy, and palliative therapy. However, no standard approach has been clearly identified for second and further chemotherapy lines in MBC patients. In the phase III clinical trial EMBRACE, eribulin was particularly effective in reducing liver lesions and improving both overall survival and progression-free survival in liver MBC patients. In this series, we collected 8 case reports of Italian clinical practice in which eribulin has shown significant efficacy in reducing liver metastases in MBC patients: complete response was reported in 2 patients, and 4 patients achieved partial response. The treatment was well tolerated, thus confirming that eribulin is a suitable therapeutic option for elderly patients and for those who have metastatic HER2-negative disease. In the setting of MBC, the sequencing of therapeutic agents should consider expected response, side effects, tumor characteristics, and patient's preferences, in order to successfully tailor the most appropriate therapy beyond earlier lines.

Correction 2: Everolimus (EVE) and exemestane (EXE) in patients with advanced breast cancer aged ≥ 65 years: new lessons for clinical practice from the EVA study.

[This corrects the article DOI: 10.18632/oncotarget.25874.].

Dose-dense adjuvant chemotherapy in premenopausal breast cancer patients: A pooled analysis of the MIG1 and GIM2 phase III studies.

BACKGROUND: No evidence exists to recommend a specific chemotherapy regimen in young breast cancer patients. We performed a pooled analysis of two randomised clinical trials to evaluate the efficacy of adjuvant dose-dense chemotherapy in premenopausal breast cancer patients and its impact on the risk of treatment-induced amenorrhoea. PATIENTS AND METHODS: In the MIG1 study, node-positive or high-risk node-negative patients were randomised to 6 cycles of fluorouracil/epirubicin/cyclophosphamide every 2 (dose-dense) or 3 (standard-interval) weeks. In the GIM2 study, node-positive patients were randomised to 4 cycles of dose-dense or standard-interval EC or FEC followed by 4 cycles of dose-dense or standard-interval paclitaxel. Using individual patient data, the hazard ratio (HR) for overall survival by means of a Cox proportional hazards model and the odds ratio for treatment-induced amenorrhoea through a logistic regression model were calculated for each study. A meta-analysis of the two studies was performed using the random effect model to compute the parameter estimates. RESULTS: A total of 1,549 patients were included. Dose-dense chemotherapy was associated with a significant improved overall survival as compared to standard-interval chemotherapy (HR, 0.71; 95% confidence intervals [CI], 0.54-0.95; p = 0.021). The pooled HRs were 0.78 (95% CI, 0.54-1.12) and 0.65 (95% CI, 0.40-1.06) for patients with hormone receptor-positive and -negative tumours, respectively (interaction p = 0.330). No increased risk of treatment-induced amenorrhoea was observed with dose-dense chemotherapy (odds ratio, 1.00; 95% CI, 0.80-1.25; p = 0.989). CONCLUSION: Dose-dense adjuvant chemotherapy may be considered the preferred treatment option in high-risk premenopausal breast cancer patients.

Fluorouracil and dose-dense chemotherapy in adjuvant treatment of patients with early-stage breast cancer: an open-label, 2 × 2 factorial, randomised phase 3 trial.

BACKGROUND: Whether addition of fluorouracil to epirubicin, cyclophosphamide, and paclitaxel (EC-P) is favourable in adjuvant treatment of patients with node-positive breast cancer is controversial, as is the benefit of increased density of dosing. We aimed to address these questions in terms of improvements in disease-free survival. METHODS: In this 2 × 2 factorial, open-label, phase 3 trial, we enrolled patients aged 18-70 years with operable, node positive, early-stage breast cancer from 81 Italian centres. Eligible patients were randomly allocated in a 1:1:1:1 ratio with a centralised, interactive online system to receive either dose-dense chemotherapy (administered intravenously every 2 weeks with pegfilgrastim support) with fluorouracil plus EC-P (FEC-P) or EC-P or to receive standard-interval chemotherapy (administered intravenously every 3 weeks) with FEC-P or EC-P. The primary study endpoint was disease-free survival, assessed with the Kaplan-Meier method in the intention-to-treat population. Our primary comparisons were between dose schedule (every 2 weeks vs every 3 weeks) and dose type (FEC-P vs EC-P). This study is registered with ClinicalTrials.gov, number NCT00433420. FINDINGS: Between April 24, 2003, and July 3, 2006, we recruited 2091 patients. 88 patients were enrolled in centres that only provided standard-intensity dosing. After a median follow-up of 7·0 years (interquartile range [IQR] 4·5-6·3), 140 (26%) of 545 patients given EC-P every 3 weeks, 157 (29%) of 544 patients given FEC-P every 3 weeks, 111 (22%) of 502 patients given EC-P every 2 weeks, and 113 (23%) of 500 patients given FEC-P every 2 weeks had a disease-free survival event. For the dose-density comparison, disease-free survival at 5 years was 81% (95% CI 79-84) in patients treated every 2 weeks and 76% (74-79) in patients treated every 3 weeks (HR 0·77, 95% CI 0·65-0·92; p=0·004); overall survival rates at 5 years were 94% (93-96) and 89% (87-91; HR 0·65, 0·51-0·84; p=0·001) and for the chemotherapy-type comparison, disease-free survival at 5 years was 78% (75-81) in the FEC-P groups and 79% (76-82) in the EC-P groups (HR 1·06, 0·89-1·25; p=0·561); overall survival rates at 5 years were 91% (89-93) and 92% (90-94; 1·16, 0·91-1·46; p=0·234). Compared with 3 week dosing, chemotherapy every 2 weeks was associated with increased rate of grade 3-4 of anaemia (14 [1·4%] of 988 patients vs two [0·2%] of 984 patients; p=0·002); transaminitis (19 [1·9%] vs four [0·4%]; p=0·001), and myalgias (31 [3·1%] vs 16 [1·6%]; p=0·019), and decreased rates of grade 3-4 neutropenia (147 [14·9%] vs 433 [44·0%]; p<0·0001). Addition of fluorouracil led to increased rates of grade 3-4 neutropenia (354 [34·5%] of 1025 patients on FEC-P vs 250 [24·2%] of 1032 patients on EC-P; p<0·0001), fever (nine [0·9%] vs two [0·2%]), nausea (47 [4·6%] vs 28 [2·7%]), and vomiting (32 [3·1%] vs 15 [1·4%]). INTERPRETATION: In patients with node-positive early breast cancer, dose-dense adjuvant chemotherapy improved disease-free survival compared with standard interval chemotherapy. Addition of fluorouracil to a sequential EC-P regimen was not associated with an improved disease-free survival outcome. FUNDING: Bristol-Myers Squibb, Pharmacia, and Dompè Biotec.