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.

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.

Extended therapy with letrozole as adjuvant treatment of postmenopausal patients with early-stage breast cancer: a multicentre, open-label, randomised, phase 3 trial.

BACKGROUND: The benefit of extending aromatase inhibitor therapy beyond 5 years in the context of previous aromatase inhibitors remains controversial. We aimed to compare extended therapy with letrozole for 5 years versus the standard duration of 2-3 years of letrozole in postmenopausal patients with breast cancer who have already received 2-3 years of tamoxifen. METHODS: This multicentre, open-label, randomised, phase 3 trial was done at 69 hospitals in Italy. Women were eligible if they were postmenopausal at the time of study entry, had stage I-III histologically proven and operable invasive hormone receptor-positive breast cancer, had received adjuvant tamoxifen therapy for at least 2 years but no longer than 3 years and 3 months, had no signs of disease recurrence, and had an Eastern Cooperative Oncology Group performance status of 2 or lower. Patients were randomly assigned (1:1) to receive 2-3 years (control group) or 5 years (extended group) of letrozole (2·5 mg orally once a day). 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. Participants and investigators were not masked to treatment assignment. The primary endpoint was invasive disease-free survival in the intention-to-treat population. Safety analysis was done for patients who received at least 1 month of study treatment. This trial was registered with EudraCT, 2005-001212-44, and ClinicalTrials.gov, NCT01064635. FINDINGS: Between Aug 1, 2005, and Oct 24, 2010, 2056 patients were enrolled and randomly assigned to receive letrozole for 2-3 years (n=1030; control group) or for 5 years (n=1026; extended group). After a median follow-up of 11·7 years (IQR 9·5-13·1), disease-free survival events occurred in 262 (25·4%) of 1030 patients in the control group and 212 (20·7%) of 1026 in the extended group. 12-year disease-free survival was 62% (95% CI 57-66) in the control group and 67% (62-71) in the extended group (hazard ratio 0·78, 95% CI 0·65-0·93; p=0·0064). The most common grade 3 and 4 adverse events were arthralgia (22 [2·2%] of 983 patients in the control group vs 29 [3·0%] of 977 in the extended group) and myalgia (seven [0·7%] vs nine [0·9%]). There were three (0·3%) serious treatment-related adverse events in the control group and eight (0·8%) in the extended group. No deaths related to toxic effects were observed. INTERPRETATION: In postmenopausal patients with breast cancer who received 2-3 years of tamoxifen, extended treatment with 5 years of letrozole resulted in a significant improvement in disease-free survival compared with the standard 2-3 years of letrozole. Sequential endocrine therapy with tamoxifen for 2-3 years followed by letrozole for 5 years should be considered as one of the optimal standard endocrine treatments for postmenopausal patients with hormone receptor-positive breast cancer. FUNDING: Novartis and the Italian Ministry of Health. TRANSLATION: For the Italian translation of the abstract see Supplementary Materials section.

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.