Neoadjuvant chemotherapy for breast cancer allows individual tumor response to be assessed depending on molecular subtype, and to judge the impact of response to therapy on recurrence-free survival (RFS). The multicenter I-SPY 1 TRIAL evaluated patients with ≥3 cm tumors by using early imaging and molecular signatures, with outcomes of pathologic complete response (pCR) and RFS. The current analysis was performed using data from patients who had molecular profiles and did not receive trastuzumab. The various molecular classifiers tested were highly correlated. Categorization of breast cancer by molecular signatures enhanced the ability of pCR to predict improvement in RFS compared to the population as a whole. In multivariate analysis, the molecular signatures that added to the ability of HR and HER2 receptors, clinical stage, and pCR in predicting RFS included 70-gene signature, wound healing signature, p53 mutation signature, and PAM50 risk of recurrence. The low risk signatures were associated with significantly better prognosis, and also identified additional patients with a good prognosis within the no pCR group, primarily in the hormone receptor positive, HER-2 negative subgroup. The I-SPY 1 population is enriched for tumors with a poor prognosis but is still heterogeneous in terms of rates of pCR and RFS. The ability of pCR to predict RFS is better by subset than it is for the whole group. Molecular markers improve prediction of RFS by identifying additional patients with excellent prognosis within the no pCR group.Electronic supplementary materialThe online version of this article (doi:10.1007/s10549-011-1895-2) contains supplementary material, which is available to authorized users.

A B S T R A C T PurposeNeoadjuvant chemotherapy for breast cancer provides critical information about tumor response; how best to leverage this for predicting recurrence-free survival (RFS) is not established. The I-SPY 1 TRIAL (Investigation of Serial Studies to Predict Your Therapeutic Response With Imaging and Molecular Analysis) was a multicenter breast cancer study integrating clinical, imaging, and genomic data to evaluate pathologic response, RFS, and their relationship and predictability based on tumor biomarkers. Patients and MethodsEligible patients had tumors Ն 3 cm and received neoadjuvant chemotherapy. We determined associations between pathologic complete response (pCR; defined as the absence of invasive cancer in breast and nodes) and RFS, overall and within receptor subsets. ResultsIn 221 evaluable patients (median tumor size, 6.0 cm; median age, 49 years; 91% classified as poor risk on the basis of the 70-gene prognosis profile), 41% were hormone receptor (HR) negative, and 31% were human epidermal growth factor receptor 2 (HER2) positive. For 190 patients treated without neoadjuvant trastuzumab, pCR was highest for HR-negative/HER2-positive patients (45%) and lowest for HRpositive/HER2-negative patients (9%). Achieving pCR predicted favorable RFS. For 172 patients treated without trastuzumab, the hazard ratio for RFS of pCR versus no pCR was 0.29 (95% CI, 0.07 to 0.82). pCR was more predictive of RFS by multivariate analysis when subtype was taken into account, and point estimates of hazard ratios within the HR-positive/HER2-negative (hazard ratio, 0.00; 95% CI, 0.00 to 0.93), HR-negative/HER2-negative (hazard ratio, 0.25; 95% CI, 0.04 to 0.97), and HER2-positive (hazard ratio, 0.14; 95% CI, 0.01 to 1.0) subtypes are lower. Ki67 further improved the prediction of pCR within subsets. ConclusionIn this biologically high-risk group, pCR differs by receptor subset. pCR is more highly predictive of RFS within every established receptor subset than overall, demonstrating that the extent of outcome advantage conferred by pCR is specific to tumor biology.

Purpose Cyclin-dependent kinase (CDK) 4/6 drives cell proliferation in estrogen receptor positive (ER+) breast cancer. This single-arm phase II neoadjuvant trial (NeoPalAna) assessed the anti-proliferative activity of the CDK4/6 inhibitor palbociclib in primary breast cancer as a prelude to adjuvant studies. Experimental Design Eligible patients with clinical stage II/III ER+/HER2- breast cancer received anastrozole 1mg daily for 4 weeks (cycle 0) (with goserelin if premenopausal), followed by adding palbociclib (125mg daily on days 1-21) on cycle 1 day 1 (C1D1) for four 28-day cycles unless C1D15 Ki67>10%, in which case patients went off study due to inadequately response. Anastrozole was continued until surgery, which occurred 3-5 weeks post palbociclib exposure. Later patients received additional 10-12 days of palbociclib (Cycle 5) immediately before surgery. Serial biopsies at baseline, C1D1, C1D15, and surgery were analyzed for Ki67, gene expression and mutation profiles. The primary endpoint was Complete Cell Cycle Arrest (CCCA: central Ki67<2.7%). Results Fifty patients enrolled. The CCCA rate was significantly higher after adding palbociclib to anastrozole (C1D15 87% vs C1D1 26%, p<0.001). Palbociclib enhanced cell cycle control over anastrozole monotherapy regardless of luminal subtype (A vs B) and PIK3CA status with activity observed across a broad range of clinicopathological and mutation profiles. Ki67 recovery at surgery following palbociclib washout was suppressed by cycle 5 palbociclib. Resistance was associated with non-luminal subtypes and persistent E2F-target gene expression. Conclusions Palbociclib is an active anti-proliferative agent for early-stage breast cancer resistant to anastrozole, however, prolonged administration may be necessary to maintain its effect.

Purpose: The Krü ppel-like transcription factor KLF4/ GKLF induces both malignant transformation and a slowgrowth phenotype in vitro. Although KLF4 expression is increased in most cases of breast cancer, it was unknown whether these cases represent a distinct subtype with a different clinical outcome.Experimental Design: We examined expression of KLF4 by immunostaining 146 cases of human primary infiltrating ductal carcinoma of the breast. Staining patterns were correlated with clinical outcome and with established prognostic factors.Results: Subcellular localization exhibited case-to-case variation. Tumors with high nuclear staining and low cytoplasmic staining were termed type 1. For patients with early-stage disease (i.e., stage I or IIA), type 1 staining was associated with eventual death because of breast cancer (hazard ratio, 2.8; 95% confidence interval, 1.23-6.58; P ‫؍‬ 0.011). The association was stronger in patients with earlystage cancer and small primary tumors (i.e., <2.0 cm in diameter; hazard ratio, 4.3; 95% confidence interval, 1.75-10.62; P < 0.001). For patients with early-stage disease, multivariate analysis indicated that type 1 staining was independently associated with outcome (adjusted hazard ratio 2.6; 95% confidence interval, 1.10 -6.05; P ‫؍‬ 0.029). Type 1 staining was also associated with high histological grade (P ‫؍‬ 0.032), increased expression of Ki67 (P ‫؍‬ 0.016), and reduced expression of BCL2 (P ‫؍‬ 0.032). In vitro, KLF4 was localized within the nucleus of transformed RK3E epithelial cells, consistent with a nuclear function of this transcription factor during induction of malignant transformation.Conclusions: The results suggest that localization of KLF4 in the nucleus of breast cancer cells is a prognostic factor and identify KLF4 as a marker of an aggressive phenotype in early-stage infiltrating ductal carcinoma.

Purpose Obesity increases risk for all-cause and breast cancer mortality and comorbidities in women who have been diagnosed and treated for breast cancer. The Exercise and Nutrition to Enhance Recovery and Good Health for You (ENERGY) study is the largest weight loss intervention trial among survivors of breast cancer to date. Methods In this multicenter trial, 692 overweight/obese women who were, on average, 2 years since primary treatment for early-stage breast cancer were randomly assigned to either a group-based behavioral intervention, supplemented with telephone counseling and tailored newsletters, to support weight loss or a less intensive control intervention and observed for 2 years. Weight and blood pressure were measured at 6, 12, 18, and 24 months. Longitudinal mixed models were used to analyze change over time. Results At 12 months, mean weight loss was 6.0% of initial weight in the intervention group and 1.5% in the control group (P < .001). At 24 months, mean weight loss in the intervention and control groups was 3.7% and 1.3%, respectively (P < .001). Favorable effects of the intervention on physical activity and blood pressure were observed. The weight loss intervention was more effective among women older than 55 years than among younger women. Conclusion A behavioral weight loss intervention can lead to clinically meaningful weight loss in overweight/obese survivors of breast cancer. These findings support the need to conduct additional studies to test methods that support sustained weight loss and to examine the potential benefit of intentional weight loss on breast cancer recurrence and survival.