Efficacy of adjuvant chemotherapy schedules for breast cancer according to body mass index: results from the phase III GIM2 trial.

BACKGROUND: The phase III GIM2 trial showed improved disease-free survival (DFS) and overall survival (OS) with adjuvant dose-dense (DD) as compared with standard-interval (SI) chemotherapy in women with node-positive early-stage breast cancer (BC). This exploratory analysis aimed to investigate the benefit of different schedules according to body mass index (BMI) in this trial. PATIENTS AND METHODS: This analysis explored the efficacy, in terms of DFS and OS, of different chemotherapy schedules according to BMI. Univariate and multivariable Cox proportional hazard models, adjusted for relevant prognostic factors, were used. RESULTS: Out of 2091 patients enrolled, 1925 with known baseline BMI were randomized in the DD versus SI comparison and therefore included in this analysis: 31.6% were overweight and 19.3% obese. Overweight and obesity were significantly associated with postmenopausal status, pT >2, and pN >2 tumors. After a median follow-up of 15.0 years (interquartile range 8.4-16.3 years), multivariable Cox survival models demonstrated no association of different BMI categories on DFS [adjusted hazard ratio (adjHR) 0.96, 95% confidence interval (CI) 0.80-1.15 and adjHR 1.11, 95% CI 0.91-1.35 for overweight and obese patients, respectively, compared to patients with normal BMI] or OS (adjHR 0.90, 95% CI 0.71-1.14 and adjHR 1.18, 95% CI 0.92-1.52 for overweight and obese patients, respectively). No significant interaction was found between BMI and treatment schedule in terms of DFS (Pfor interaction = 0.56) or OS (Pfor interaction = 0.19). The survival benefit of DD chemotherapy was observed irrespective of different BMI categories, with a more pronounced benefit for overweight and obese patients. CONCLUSION: In node-positive BC patients, DD schedule should be considered the preferred schedule irrespective of BMI.

Association of tumor-infiltrating lymphocytes with distant disease-free survival in the ShortHER randomized adjuvant trial for patients with early HER2+ breast cancer.

BACKGROUND: There is the need to identify new prognostic markers to refine risk stratification for HER2-positive early breast cancer patients. The aim of this study was to evaluate the association of tumor-infiltrating lymphocytes (TILs) with distant disease-free survival (DDFS) in patients with HER2-positive early breast cancer enrolled in the ShortHER adjuvant trial which compared 9 weeks versus 1-year trastuzumab in addition to chemotherapy, and to test the interaction between TILs and treatment arm. PATIENTS AND METHODS: Stromal TILs were assessed for 866 cases on centralized hematoxylin and eosin-stained tumor slides. The association of TILs as 10% increments with DDFS was assessed with Cox models. Kaplan-Meier curves were estimated for patients with TILs ≥20% and TILs <20%. Median follow-up was 6.1 years. RESULTS: Median TILs was 5% (Q1-Q3 1%-15%). Increased TILs were independently associated with better DDFS in multivariable model [hazard ratio (HR) 0.73, 95% confidence interval (CI) 0.59-0.89, P = 0.006, for each 10% TILs increment]. Five years DDFS rates were 91.1% for patients with TILs <20% and 95.7% for patients with TILs ≥20% (P = 0.025). The association between 10% TILs increments and DDFS was significant for patients randomized to 9 weeks of trastuzumab (HR 0.60, 95% CI 0.41-0.88) but not for patients treated with 1 year of trastuzumab (HR 0.89, 95% CI 0.71-1.12; test for interaction P = 0.088). For patients with TILs <20%, the HR for the comparison between the short versus the long arm was 1.75 (95% CI 1.09-2.80, P=0.021); whereas, for patients with TILs ≥20% the HR for the comparison of short versus long arm was 0.23 (95% CI 0.05-1.09, P = 0.064), resulting in a significant interaction (P = 0.015). CONCLUSIONS: TILs are an independent prognostic factor for HER2-positive early breast cancer patients treated with adjuvant chemotherapy and trastuzumab and may refine the ability to identify patients at low risk of relapse eligible for de-escalated adjuvant therapy.

Nine weeks versus 1 year adjuvant trastuzumab in combination with chemotherapy: final results of the phase III randomized Short-HER study‡.

Background: Chemotherapy plus 1-year trastuzumab is the standard adjuvant treatment of HER2-positive breast cancer. The efficacy of less extended trastuzumab exposure is under investigation. The short-HER study was aimed to assess the non-inferiority of 9 weeks versus 1 year of adjuvant trastuzumab combined with chemotherapy. Patients and methods: HER2-positive breast cancer patients with node-positive or, if node negative, with at least one risk factor (pT>2 cm, G3, lympho-vascular invasion, Ki-67 > 20%, age ≤35 years, or hormone receptor negativity) were randomly assigned to receive sequential anthracycline-taxane combinations plus 1-year trastuzumab (arm A, long) or plus 9 weeks trastuzumab (arm B, short). This study was designed as a non-inferiority trial with disease-free survival (DFS) as primary end point. A DFS hazard ratio (HR) <1.29 was chosen as the non-inferiority margin. Analyses according to the frequentist and Bayesian approach were planned. Secondary end points included 2-year failure rate and cardiac safety. Results: A total of 1254 patients from 82 centers were randomized (arm A, long: n = 627; arm B, short: n = 626). Five-year DFS is 88% in the long and 85% in the short arm. The HR is 1.13 (90% CI 0.89-1.42), with the upper limit of the CI crossing the non-inferiority margin. According to the Bayesian analysis, the probability that the short arm is non-inferior to the long one is 80%. The 5-year overall survival (OS) is 95.2% in the long and 95.0% in the short arm (HR 1.07, 90% CI 0.74-1.56). Cardiac events are significantly lower in the short arm (risk-ratio 0.33, 95% CI 0.22-0.50, P < 0.0001). Conclusions: This study failed to show the non-inferiority of a shorter trastuzumab administration. One-year trastuzumab remains the standard. However, a 9-week administration decreases the risk of severe cardiac toxicity and can be an option for patients with cardiac events during treatment and for those with a low risk of relapse. Trial Registration: EUDRACT number: 2007-004326-25; NCI ClinicalTrials.gov number: NCT00629278.

Prognostic impact of interval breast cancer detection in women with pT1a N0M0 breast cancer with HER2-positive status: Results from a multicentre population-based cancer registry study.

BACKGROUND: Although human epidermal growth factor receptor 2 (HER2) overexpression is associated with poor prognosis, patients (pts) with pT1a N0M0 breast cancers (BCs) have an excellent outcome across all subtypes. Interval cancers (ICs) have poorer survival than screen-detected (SD) tumours, and an association has been reported between ICs and HER2 overexpression. We aimed to determine, in a general population of pT1a N0M0 BCs with known screening status, whether HER2-positive ICs have a poorer outcome than HER2-positive SD cancers. METHODS: We evaluated all incident pT1a N0M0 BCs (n = 874) collected in the Emilia-Romagna region (Italy) from 2003 to 2009 and diagnosed in women aged 50-69. Pts unexposed to screening, with unknown HER2 status and/or treated with adjuvant trastuzumab were excluded from analysis. RESULTS: Sixty-one percent of the BCs were SD, whereas 19% were ICs. BCs with high histologic grade, hormone receptor-negative or HER2-positive status (odds ratio=1.7; 95% confidence interval [CI]: 1.1-2.7) were more likely ICs. Median follow-up was 115 months. The 10-year invasive disease-free survival (iDFS) for HER2-positive ICs was lower than that for HER2-positive SD cancers: 75.0% (95% CI: 55.5%-94.5%) versus 93.8% (95% CI: 86.5%-100%). An interaction between ICs and HER2-positive status was found for poorer iDFS after adjusting for prognostic variables (HR = 5.3; 95% CI: 1.6-16.7). CONCLUSIONS: IC detection may identify pts with HER2-positive pT1a N0M0 tumours in whom the rate of recurrence justifies consideration for conventional, anti-HER2, adjuvant treatment.

Immunoglobulin G fragment C receptor polymorphisms and efficacy of preoperative chemotherapy plus trastuzumab and lapatinib in HER2-positive breast cancer.

Lapatinib enhances antibody-dependent cell-mediated cytotoxicity (ADCC) activity of trastuzumab. FcγR polymorphisms have been associated with both ADCC and clinical activity of trastuzumab in HER2+ breast cancer (BC) patients (pts). We analyzed FcγRIIa-H131R and FcγRIIIa-V158F polymorphisms in the CHER-LOB trial population of HER2+ BCs treated with preoperative chemotherapy plus trastuzumab (arm A), lapatinib (arm B) or both (arm C). Genotyping was successfully performed in 73/121 (60%) pts. A significant improvement in pathological complete response (pCR) rate was observed for the combination arm C, but only in FcγRIIIa V allele carriers (C vs A, 67 vs 27%, P=0.043; C vs B, 67 vs 22%, P=0.012). An independent interaction between arm C and FcγRIIIa V allele was found for pCR (odds ratio=9.4; 95% confidence interval, 2.3-39.6; P=0.003). No significant associations were observed between pCR and FcγRIIa polymorphism, and between pre-treatment tumor-infiltrating lymphocytes and FcγR polymorphisms. Our study provides evidence for a FcγRIIIa V allele-restricted pCR benefit from neoadjuvant trastuzumab plus lapatinib in HER2+ BC.