Maribel Casas

Clinical validation of the EndoPredict test in node-positive, chemotherapy-treated ER+/HER2− breast cancer patients: results from the GEICAM 9906 trial

IntroductionEndoPredict (EP) is an RNA-based multigene test that predicts the likelihood of distant recurrence in patients with estrogen receptor-positive (ER+), human epidermal growth factor receptor 2–negative (HER2−) breast cancer (BC) who are being treated with adjuvant endocrine therapy. Herein we report the prospective-retrospective clinical validation of EP in the node-positive, chemotherapy-treated, ER+/HER2− BC patients in the GEICAM 9906 trial.MethodsThe patients (N = 1,246) were treated either with six cycles of fluorouracil, epirubicin and cyclophosphamide (FEC) or with four cycles of FEC followed by eight weekly courses of paclitaxel (FEC-P), as well as with endocrine therapy if they had hormone receptor–positive disease. The patients were assigned to EP risk categories (low or high) according to prespecified cutoff levels. The primary endpoint in the clinical validation of EP was distant metastasis-free survival (MFS). Metastasis rates were estimated using the Kaplan-Meier method, and multivariate analysis was performed using Cox regression.ResultsThe molecular EP score and the combined molecular and clinical EPclin score were successfully determined in 555 ER+/HER2− tumors from the 800 available samples in the GEICAM 9906 trial. On the basis of the EP, 25% of patients (n = 141) were classified as low risk. MFS was 93% in the low-risk group and 70% in the high-risk group (absolute risk reduction = 23%, hazard ratio (HR) = 4.8, 95% confidence interval (CI) = 2.5 to 9.5; P < 0.0001). Multivariate analysis showed that, in this ER+/HER2− cohort, EP results are an independent prognostic parameter after adjustment for age, grade, lymph node status, tumor size, treatment arm, ER and progesterone receptor (PR) status and proliferation index (Ki67). Using the predefined EPclin score, 13% of patients (n = 74) were assigned to the low-risk group, who had excellent outcomes and no distant recurrence events (absolute risk reduction vs high-risk group = 28%; P < 0.0001). Furthermore, EP was prognostic in premenopausal patients (HR = 6.7, 95% CI = 2.4 to 18.3; P = 0.0002) and postmenopausal patients (HR = 3.3, 95% CI = 1.3 to 8.5; P = 0.0109). There were no statistically significant differences in MFS between treatment arms (FEC vs FEC-P) in either the high- or low-risk groups. The interaction test results between the chemotherapy arm and the EP score were not significant.ConclusionsEP is an independent prognostic parameter in node-positive, ER+/HER2− BC patients treated with adjuvant chemotherapy followed by hormone therapy. EP did not predict a greater efficacy of FEC-P compared to FEC alone.

Prospective study of the impact of the Prosigna assay on adjuvant clinical decision-making in unselected patients with estrogen receptor positive, human epidermal growth factor receptor negative, node negative early-stage breast cancer

Abstract Purpose: Improved understanding of risk of recurrence (ROR) is needed to reduce cases of recurrence and more effectively treat breast cancer patients. The purpose of this study was to examine how a gene-expression profile (GEP), identified by Prosigna, influences physician adjuvant treatment selection for early breast cancer (EBC) and the effects of this influence on optimizing adjuvant treatment recommendations in clinical practice. Methods: A prospective, observational, multicenter study was carried out in 15 hospitals across Spain. Participating medical oncologists completed pre-assessment, post-assessment, and follow-up questionnaires recording their treatment recommendations and confidence in these recommendations, before and after knowing the patient’s ROR. Patients completed questionnaires on decision-making, anxiety, and health status. Results: Between June 2013 and January 2014, 217 patients enrolled and a final 200 were included in the study. Patients were postmenopausal, estrogen receptor positive, human epidermal growth hormone factor negative, and node negative with either stage 1 or stage 2 tumors. After receiving the GEP results, treatment recommendations were changed for 40 patients (20%). The confidence of medical oncologists in their treatment recommendations increased in 41.6% and decreased in 6.5% of total cases. Patients reported lower anxiety after physicians made treatment recommendations based on the GEP results (p < 0.05). Conclusions: Though this study does not include evaluation of the impact of GEP on long-term outcomes, it was found that GEP results influenced the treatment decisions of medical oncologists and their confidence in adjuvant therapy selection. Patients’ anxiety about the selected adjuvant therapy decreased with use of the GEP.

Epirubicin Plus Cyclophosphamide Followed by Docetaxel Versus Epirubicin Plus Docetaxel Followed by Capecitabine As Adjuvant Therapy for Node-Positive Early Breast Cancer: Results From the GEICAM/2003-10 Study

PURPOSE Capecitabine is an active drug in metastatic breast cancer (BC). GEICAM/2003-10 is an adjuvant trial to investigate the integration of capecitabine into a regimen of epirubicin and docetaxel for node-positive early BC. PATIENTS AND METHODS Patients with operable node-positive BC (T1-3/N1-3) were eligible. After surgery, 1,384 patients were randomly assigned to receive epirubicin plus cyclophosphamide (EC; 90 and 600 mg/m(2), respectively, × four cycles), followed by docetaxel (100 mg/m(2) × four cycles; EC-T) or epirubicin plus docetaxel (ET; 90 and 75 mg/m(2), respectively, × four cycles), followed by capecitabine (1,250 mg/m(2) twice a day on days 1 to 14, × four cycles; ET-X); all regimens were given every 3 weeks. The primary end point was invasive disease-free survival. Secondary end points included safety (with an alopecia-specific study) and overall survival (OS). RESULTS After a median follow-up of 6.6 years and 297 events, 86% of patients who received EC-T and 82% of those who received ET-X were invasive disease free at 5 years (hazard ratio, 1.30; 95% CI, 1.03 to 1.64; log-rank P = .03). The OS difference between arms was not statistically significant (hazard ratio, 1.13; 95% CI, 0.82 to 1.55; log-rank P = .46). The most frequent grade 3 to 4 adverse events in the EC-T versus ET-X arms were neutropenia (19% v 10%), with 7% febrile neutropenia across arms; fatigue (13% v 11%); diarrhea (3% v 11%); hand-foot syndrome (2% v 20%); mucositis (6% v 5%); vomiting (both, 5%); and myalgia (4.5% v 1%). Incomplete scalp hair recovery was more frequent in the EC-T than ET-X arm (30% v 14%), and patients who received EC-T wore wigs significantly longer than those who received ET-X (8.35 v 6.03 months). CONCLUSION Invasive disease-free survival, but not OS, was significantly superior for patients with node-positive early BC who received the adjuvant standard schedule EC-T than for those who received the experimental ET-X regimen. Toxicity profiles differed substantially across arms.

High Proliferation Predicts Pathological Complete Response to Neoadjuvant Chemotherapy in Early Breast Cancer

BACKGROUND In the neoadjuvant setting, changes in the proliferation marker Ki67 are associated with primary endocrine treatment efficacy, but its value as a predictor of response to chemotherapy is still controversial. PATIENTS AND METHODS We analyzed 262 patients with centralized basal Ki67 immunohistochemical evaluation derived from 4 GEICAM (Spanish Breast Cancer Group) clinical trials of neoadjuvant chemotherapy for breast cancer. The objective was to identify the optimal threshold for Ki67 using the receiver-operating characteristic curve method to maximize its predictive value for chemotherapy benefit. We also evaluated the predictive role of the defined Ki67 cutoffs for molecular subtypes defined by estrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2). RESULTS A basal Ki67 cutpoint of 50% predicted pathological complete response (pCR). Patients with Ki67 >50% achieved a pCR rate of 40% (36 of 91) versus a pCR rate of 19% in patients with Ki67 ≤ 50% (33 of 171) (p = .0004). Ki67 predictive value was especially relevant in ER-HER2- and ER-HER2+ patients (pCR rates of 42% and 64%, respectively, in patients with Ki67 >50% versus 15% and 45%, respectively, in patients with Ki67 ≤ 50%; p = .0337 and .3238, respectively). Both multivariate analyses confirmed the independent predictive value of the Ki67 cutpoint of 50%. CONCLUSION Basal Ki67 proliferation index >50% should be considered an independent predictive factor for pCR reached after neoadjuvant chemotherapy, suggesting that cell proliferation is a phenomenon closely related to chemosensitivity. These findings could help to identify a group of patients with a potentially favorable long-term prognosis. IMPLICATIONS FOR PRACTICE The use of basal Ki67 status as a predictive factor of chemotherapy benefit could facilitate the identification of a patient subpopulation with high probability of achieving pathological complete response when treated with primary chemotherapy, and thus with a potentially favorable long-term prognosis.

Abstract P3-07-42: Predicting outcome and benefit to first-line bevacizumab in advanced/metastatic hormone receptor (HR)+/HER2-negative breast cancer (BC) treated with endocrine therapy: A correlative science study from the LEA phase III clinical trial (GEICAM/2006-11_GBG 051)

Introduction: The role of bevacizumab in combination with chemotherapy in metastatic BC is controversial, and no biomarker exists as of today that predicts benefit to this agent. In the LEA clinical trial, a numerical, statistically non-significant benefit from the addition of bevacizumab to endocrine therapy (ET) was observed in the first-line metastatic setting (18.4 vs. 13.8 months of Progression-Free Survival (PFS), p=0.14). Here, we explored various gene expression-based predictors of outcome and benefit to bevacizumab. Methods and materials: LEA trial randomized 380 patients with HR+/HER2- advanced disease to bevacizumab in combination with ET (ET+B) vs. ET alone. Primary endpoint was PFS. Expression of BC selected genes was evaluated in formalin-fixed paraffin-embedded (FFPE) primary tumors using the nCounter platform from patients randomized in Spain that consent for biomarker analyses. The following variables were evaluated: 1) research-based PAM50 intrinsic subtypes (categorical variable; Luminal A, Luminal B, HER2-enriched, Basal-like and Normal-like); 2) research-based PAM50 signatures (continuous variable; scores showing the distant of the gene expression values of an individual sample compared to the centroid gene values for each PAM50 intrinsic subtype); 3) risk of recurrence (ROR) groups (low, medium and high); 4) the 13-gene hypoxia/VEGF signature (continuous); and 5) Ki67 by immunohistochemistry (continuous). Uni- and multivariable Cox models for PFS were used to test the prognostic significance of each variable. To determine whether each variable is predictive of bevacizumab benefit, we tested the interaction term of each variable by treatment arm in a Cox model. Results: Tumor samples from 103 patients were analyzed: 55 (53%) in ET+B arm and 49 (47%) in ET arm. Subtype distribution was as follows: 57 (55.3%) Luminal A, 32 (31.1%) Luminal B, 5 (4.9%) HER2-enriched, 1 (1.0%) Basal-like, and 8 (7.8%) normal-like. In a univariate analysis, Luminal B tumors had a poorer outcome using Luminal A as reference (13.8 vs. 21.3 months, respectively; (hazard ratio, HR=1.80, 95% CI 1.10-2.95, p=0.019). Concordant with this finding, Luminal A signature was associated with a better outcome. Similarly, ROR-P high group showed a poorer outcome than ROR-P low group (8.5 vs. 19.4 months; HR=2.88, 95% CI 1.30-6.35, p=0.009). Neither VEGF-13 signature nor Ki67 were found to be associated with PFS. Similar findings were obtained after adjustment for treatment, age, previous ET, ECOG, visceral disease and number of metastatic sites. In terms of treatment benefit, the HER2-enriched signature was the only variable found predictive of bevacizumab PFS benefit in univariate (p=0.010) and multivariate (p=0.015) analyses. Conclusions: In advanced HR+/HER2- disease, intrinsic subtype (i.e. Luminal A vs. B) independently predicts PFS following first-line ET. In addition, HR+/HER2-negative tumors with high expression of the HER2-enriched signature, a biomarker of estrogen-independence, benefit the most from bevacizumab. Further validation of these prognostic and predictive biomarkers is warranted. Citation Format: Prat A, de la Haba-Rodriguez J, Guerrero A, Garcia-Saenz JA, Morales S, Anton A, Munoz M, Ramos M, Martinez-Janez N, Margeli M, Servitja S, Rojo F, Galvan P, Gonzalez S, Cruz J, Sanchez-Rovira P, Perello A, Rodriguez-Martin C, Casas M, Carrasco E, Caballero R, Martin M. Predicting outcome and benefit to first-line bevacizumab in advanced/metastatic hormone receptor (HR)+/HER2-negative breast cancer (BC) treated with endocrine therapy: A correlative science study from the LEA phase III clinical trial (GEICAM/2006-11_GBG 051). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-07-42.