Gene expression profiles provide important information about the biology of breast tumors and can be used to develop prognostic tests. However, the implementation of quantitative RNA-based testing in routine molecular pathology has not been accomplished, so far. The EndoPredict assay has recently been described as a quantitative RT-PCR-based multigene expression test to identify a subgroup of hormone–receptor-positive tumors that have an excellent prognosis with endocrine therapy only. To transfer this test from bench to bedside, it is essential to evaluate the test–performance in a multicenter setting in different molecular pathology laboratories. In this study, we have evaluated the EndoPredict (EP) assay in seven different molecular pathology laboratories in Germany, Austria, and Switzerland. A set of ten formalin-fixed paraffin-embedded tumors was tested in the different labs, and the variance and accuracy of the EndoPredict assays were determined using predefined reference values. Extraction of a sufficient amount of RNA and generation of a valid EP score was possible for all 70 study samples (100%). The EP scores measured by the individual participants showed an excellent correlation with the reference values, respectively, as reflected by Pearson correlation coefficients ranging from 0.987 to 0.999. The Pearson correlation coefficient of all values compared to the reference value was 0.994. All laboratories determined EP scores for all samples differing not more than 1.0 score units from the pre-defined references. All samples were assigned to the correct EP risk group, resulting in a sensitivity and specificity of 100%, a concordance of 100%, and a kappa of 1.0. Taken together, the EndoPredict test could be successfully implemented in all seven participating laboratories and is feasible for reliable decentralized assessment of gene expression in luminal breast cancer.

Neoadjuvant chemotherapy (NaCT) and neoadjuvant endocrine therapy (NET) can reduce pre-operative tumour burden in patients with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative early-stage breast cancer. This prospective translational study assessed the ability of a 12-gene molecular score (MS; EndoPredict®) to predict response to NaCT or NET within the ABCSG-34 trial. Hormone receptor (HR)-positive, HER2-negative samples from patients in the ABCSG-34 randomized phase II trial were selected and EndoPredict testing was performed to generate a 12-gene MS. ABCSG-34 patients were assigned to receive either NaCT or NET based on menopausal status, HR expression, grade and Ki67. Response was measured by residual cancer burden (RCB). Patients selected for NaCT generally had high-risk disease by 12-gene MS (125/134), while slightly more patients treated with NET had low-risk disease (44/83). Low-risk NaCT-treated and high-risk NET-treated tumours responded poorly (NPV 100% [95% CI 66.4%-100%] and NPV 92.3% [95% CI 79.1%-98.4%], respectively]. The 12-gene MS significantly predicted treatment response for NaCT (AUC 0.736 [95% CI 0.63-0.84]) and NET (AUC 0.726 [95% CI 0.60-0.85]). The 12-gene MS predicted RCB after treatment with neoadjuvant therapies for patients with HR-positive, HER2-negative early-stage breast cancer. Tumours with low MS were unlikely to benefit from NaCT, whereas a high MS predicted resistance to NET. This additional biologic information can aid personalized treatment selection in daily practice and builds a strong rationale to use EndoPredict in biomarker-driven studies in the neoadjuvant setting.

Purpose: The EndoPredict prognostic assay is validated to predict distant recurrence and response to chemotherapy primarily in post-menopausal women with estrogen receptor–positive (ER+), HER2− breast cancer. This study evaluated the performance of EndoPredict in pre-menopausal women. Experimental Design: Tumor samples from 385 pre-menopausal women with ER+, HER2− primary breast cancer (pT1-3, pN0-1) who did not receive chemotherapy in addition to endocrine therapy were tested with EndoPredict to produce a 12-gene EP molecular score and an integrated EPclin score that includes pathologic tumor size and nodal status. Associations of molecular and EPclin scores with 10-year distant recurrence–free survival (DRFS) were evaluated by Cox proportional hazards models and Kaplan–Meier analysis. Results: After a median follow-up of 9.7 years, both the EP molecular score and the molecular-clinicopathologic EPclin score were associated with increased risk of distant recurrence [HR, 1.33; 95% confidence interval (CI), 1.18–1.50; P = 7.2 × 10–6; HR, 3.58; 95% CI, 2.26–5.66; P = 9.8 × 10–8, respectively]. Both scores remained significant after adjusting for clinical factors in multivariate analysis. Patients with low-risk EPclin scores (64.7%) had significantly improved DRFS compared with high-risk patients (HR, 4.61; 95% CI, 1.40–15.17; P = 4.2 × 10–3). At 10 years, patients with low-risk and high-risk EPclin scores had a DRFS of 97% (95% CI, 93%–99%) and 76% (95% CI, 67%–82%), respectively. Conclusions: The EPclin score is strongly associated with DRFS in pre-menopausal women who received adjuvant endocrine therapy alone. On the basis of these data, pre-menopausal women with EPclin low-risk breast cancer may be treated with endocrine therapy only and safely forgo adjuvant chemotherapy.

The use of antisense oligodeoxyribonucleotides (ODN) is a potential method to switch off gene expression. The poor cellular uptake of ODN in primary cells still is a limiting factor that may contribute to the lack of functional efficacy. Various forms of cationic lipids have been developed for efficient delivery of nucleic acids into different cell types. We examined the two cationic lipids DOTAP and DOSPER to improve uptake of ODN into primary human hematopoietic cells. Using a radiolabeled 23-mer, ODN uptake into blood-derived mononuclear cells could be increased 42- to 93-fold by DOTAP and 440- to 1,025-fold by DOSPER compared with application of ODN alone. DOTAP was also effective for delivery of ODN into leukocytes within whole blood, which may resemble more closely the in vivo conditions. As assessed by fluorescein isothiocyanate–conjugated ODN both cationic lipids enhanced cytoplasmic accumulation of ODN in endosome/lysosome-like structures with a partial shift of fluorescence to the whole cytoplasm and the nucleus following an incubation of 24 hours. ODN uptake by cationic lipids into different hematopoietic cell subsets was examined by dual-color immunofluorescence analysis with subset-specific monoclonal antibodies. We found a cell type–dependent delivery of ODN with greatest uptake in monocytes and smallest uptake in T cells. CD34⁺ cells, B cells, and granulocytes took up ODN at an intermediate level. Uptake of ODN into isolated CD34⁺cells could be increased 100- to 240-fold using cationic lipids compared with application of ODN alone. Stimulation of CD34⁺ cells by interleukin-3 (IL-3), IL-6, and stem cell factor did not significantly improve cationic lipid-mediated ODN delivery. Sequence-specific antisense effects in clonogenic assays could be shown by transfection of bcr-abl oncogene-directed antisense ODN into primary cells of patients with chronic myelogenous leukemia using this established protocol. In conclusion, cationic lipids may be useful tools for delivery of antisense ODN into primary hematopoietic cells. These studies provide a basis for clinical protocols in the treatment of hematopoietic cells in patients with hematologic malignancies and viral diseases by antisense ODN.

Background: In node negative and 1-3 positive nodes breast cancer patients with hormone receptor positive (HR+), HER2-negative (HER2-) early-stage breast cancer the indication for chemotherapy is based on clinical and pathologic risk stratification (tumor size, nodal status, grading, quantitative ER, progesterone receptor and Ki67). For further decision-making, the EndoPredict test, which combines a molecular signature with the clinical risk factors tumor size and nodal status, stratifies patients into “low risk" or “high risk” groups. Level I-B- evidence demonstrates, that EndoPredict predicts the 10 year cumulative risk of relapse and metastases in patients with HR+/HER2- primary breast cancer with endocrine treatment. Aim: In the RESCUE-Trial we document distant metastasis-free survival (DMFS), disease free survival (DFS) and overall survival (OS) events in patients who had an EndoPredict test. The primary objective is to show that 10-year DMFS of patients tested as “low risk” by EndoPredict and treated with adjuvant endocrine therapy alone is >90 %. Secondary endpoints among others include DMFS, DFS, OS in patients with EPclin “low risk” versus “high risk”. Also the proportion of patients whose treatment was concordant and non-concordant with EndoPredict test results, will be analyzed for survival. The prognostic performance of classical prognostic factors (like tumor size, nodal status, grading, quantitative ER, progesterone receptor and Ki67 level) with respect to survival will also be assessed. Eligibility: Patient with HR+/HER2- primary invasive breast cancer stage I/II and T1 to T3 with 0 to 3 positive lymph nodes will be eligible, if they had an EndoPredict test within three months before inclusion. Methods: The EndoPredict test results, tumor board decision and anti-tumor therapy will be assessed. After one year, annually (for 10 years), patients will be evaluated for treatment compliance, recurrence, metastases, and survival. The primary endpoint will be analyzed by a Kaplan-Meyer estimate for which a one-sided lower 95 % confidence interval will be given. Several secondary endpoints will be assessed in three interim analyses after completion of the 1^st, 3^rd, 5^th year and then finally after 10 years. Accrual: Start of accrual is planned for July 2018. At least 26 sites in Germany and one site in Switzerland will be active. Sponsor: The study is sponsored by the North-Eastern-German Society of Gynecological Oncology (NOGGO) e.V. Contact Information: For further information, contact NOGGO via studies@noggo.de or the leading physician Dr. Johannes Ettl via johannes.ettl@tum.de. Citation Format: Ettl J, Blohmer J-U, Denkert C, Keller M, Klein E, Kronenwett R, Neuser P, Paepke S, Schade-Brittinger C, Schnuppe K, Untch M, Wittenberg M, Kiechle M. RESCUE: Reaching for Evidence-baSed Chemotherapy Use in Endocrine sensitive breast cancer - A prospective health care study on risk assessment by the clinicomolecular test EndoPredict^® and long-term patient outcome in early luminal breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT1-12-03.