Katrin Almstedt

Targeted Therapies Overcoming Endocrine Resistance in Hormone Receptor-Positive Breast Cancer.

Breast cancer is a heterogeneous disease with different molecular subtypes. Most tumours are hormone receptor positive (luminal subtype) with potential endocrine responsiveness. Endocrine therapy is commonly used in these patients. Disease progression caused by endocrine resistance represents a significant challenge in the treatment of breast cancer. To understand the mechanisms of resistance of long-term oestrogen-deprived breast cancer cells, it is important to focus on cross-talk between steroid receptor signalling and other growth factor receptors and intracellular pathways. (Pre-)clinical trials showed that co-targeting these pathways can restore endocrine sensitivity. The focus of the current review is on the intracellular PI3K/AKT/mTOR signalling pathway and cyclin-dependant kinases (CDKs) in oestrogen receptor (ER)-positive breast cancer. Study results clearly show that both inhibition of the PI3K/AKT/mTOR pathway and CDK4/6 are promising ways to improve the efficacy of endocrine treatment in ER-positive breast cancer patients with comparably few side effects. Further clinical trials are needed to identify the patient population who would benefit most from a dual inhibition.

Epsin Family Member 3 and Ribosome-Related Genes Are Associated with Late Metastasis in Estrogen Receptor-Positive Breast Cancer and Long-Term Survival in Non-Small Cell Lung Cancer Using a Genome-Wide Identification and Validation Strategy

Background In breast cancer, gene signatures that predict the risk of metastasis after surgical tumor resection are mainly indicative of early events. The purpose of this study was to identify genes linked to metastatic recurrence more than three years after surgery. Methods Affymetrix HG U133A and Plus 2.0 array datasets with information on metastasis-free, disease-free or overall survival were accessed via public repositories. Time restricted Cox regression models were used to identify genes associated with metastasis during or after the first three years post-surgery (early- and late-type genes). A sequential validation study design, with two non-adjuvantly treated discovery cohorts (n = 409) and one validation cohort (n = 169) was applied and identified genes were further evaluated in tamoxifen-treated breast cancer patients (n = 923), as well as in patients with non-small cell lung (n = 1779), colon (n = 893) and ovarian (n = 922) cancer. Results Ten late- and 243 early-type genes were identified in adjuvantly untreated breast cancer. Adjustment to clinicopathological factors and an established proliferation-related signature markedly reduced the number of early-type genes to 16, whereas nine late-type genes still remained significant. These nine genes were associated with metastasis-free survival (MFS) also in a non-time restricted model, but not in the early period alone, stressing that their prognostic impact was primarily based on MFS more than three years after surgery. Four of the ten late-type genes, the ribosome-related factors EIF4B, RPL5, RPL3, and the tumor angiogenesis modifier EPN3 were significantly associated with MFS in the late period also in a meta-analysis of tamoxifen-treated breast cancer cohorts. In contrast, only one late-type gene (EPN3) showed consistent survival associations in more than one cohort in the other cancer types, being associated with worse outcome in two non-small cell lung cancer cohorts. No late-type gene was validated in ovarian and colon cancer. Conclusions Ribosome-related genes were associated with decreased risk of late metastasis in both adjuvantly untreated and tamoxifen-treated breast cancer patients. In contrast, high expression of epsin (EPN3) was associated with increased risk of late metastasis. This is of clinical relevance considering the well-understood role of epsins in tumor angiogenesis and the ongoing development of epsin antagonizing therapies.

Prognostic Significance of Focal Adhesion Kinase in Node-Negative Breast Cancer

Background: Focal adhesion kinase (FAK) is a cytoplasmic tyrosine kinase that plays an important role as a mediator of cell migration, invasion, proliferation and survival. Conflicting results for the prognostic role of FAK in breast cancer (BC) prompted us to determine its impact. Methods: Patients with node-negative BC entered this retrospective study. FAK expression was determined by immunohistochemistry (n = 335). The prognostic impact of FAK was examined with Cox regression analyses and Kaplan-Meier estimation in the whole cohort as well as in different molecular subtypes. Results: 151 (45.1%) had a FAK-positive BC. In univariate analyses, FAK expression showed a significant impact for shorter disease-free survival (DFS) (hazard ratio (HR) 1.54, 95% confidence interval (CI) 1.04-2.28, p = 0.030) but not for metastasis-free survival and overall survival. Significant prognostic relevance for DFS (HR 1.76, 95% CI 1.05-2.97, p = 0.033) was observed in particular in estrogen receptor-positive HER2-negative BC patients, most notably in luminal B-like tumors (HR 2.32, CI 1.20-4.48, p = 0.012). However, FAK lost its prognostic impact in multivariate Cox regression analysis. Conclusion: FAK was associated with impaired DFS in univariate analysis. Prognostic relevance for DFS was most pronounced in luminal B-like BC. However, FAK expression was not associated with an independent impact on survival for BC in multivariate analysis.

Explorative Analysis of Low-Dose Metronomic Chemotherapy with Cyclophosphamide and Methotrexate in a Cohort of Metastatic Breast Cancer Patients

Background: Low-dose metronomic chemotherapy (LDMC) is increasingly used in metastatic breast cancer (MBC). In this retrospective analysis, we examined the therapeutic effects and side effects of LDMC in a cohort of MBC patients. Methods: Patients with MBC were included when LDMC with oral cyclophosphamide (CTX) and methotrexate (MTX) was administered between 2009 and 2015. The primary endpoint was disease control rate (DCR) ≥ 24 weeks after the start of LDMC. Secondary endpoints were duration of progression-free survival (PFS), rates of discontinuation due to side effects, and DCR with regard to subgroups. Results: Retrospective data of 35 patients were available for this analysis. 31% patients achieved DCR. The median PFS was 12 weeks. 9% of patients discontinued LDMC due to adverse events. DCR was 37% in the first 2 lines and 25% in further lines of therapy. 22% of patients with multiple metastases and 35% with ≤2 different metastatic sites achieved DCR. DCR was achieved in 33% of hormone receptor(HR)-positive patients and 27% of HR-negative patients. Conclusion: The DCR of 31% is in line with the results of previous phase II studies. LDMC was well tolerated. Subgroup analysis was not able to identify a group in which LDMC was more efficient.

Prognostic impact of CD4-positive T cell subsets in early breast cancer: a study based on the FinHer trial patient population

BackgroundThe clinical importance of tumor-infiltrating cluster of differentiation 4 (CD4) T cells is incompletely understood in early breast cancer. We investigated the clinical significance of CD4, forkhead box P3 (FOXP3), and B cell attracting chemokine leukocyte chemoattractant-ligand (C-X-C motif) 13 (CXCL13) in early breast cancer.MethodsThe study is based on the patient population of the randomized FinHer trial, where 1010 patients with early breast cancer were randomly allocated to adjuvant chemotherapy containing either docetaxel or vinorelbine, and human epidermal growth factor receptor 2 (HER2)-positive patients were also allocated to trastuzumab or no trastuzumab. Breast cancer CD4, FOXP3, and CXCL13 contents were evaluated using quantitative real-time polymerase chain reaction (qRT-PCR), and their influence on distant disease-free survival (DDFS) was examined using univariable and multivariable Cox regression and Kaplan-Meier estimates in the entire cohort and in selected molecular subgroups. Interactions between variables were analyzed using Cox regression. The triple-negative breast cancer (TNBC) subset of the HE10/97 randomized trial was used for confirmation.ResultsHigh CXCL13 was associated with favorable DDFS in univariable analysis, and independently in multivariable analysis (HR 0.44, 95% CI 0.29–0.67, P ≤ 0.001), most strongly in TNBC (HR 0.39, 95% CI 0.19–0.79, P = 0.009). No significant interaction with chemotherapy or trastuzumab administration was detected. Neither tumor CD4 content nor FOXP3 content was associated with DDFS. The favorable prognostic influence of CXCL13 was confirmed in the HE10/97 trial patient population with TNBC (HR 0.30, 95% CI 0.09–0.93; P = 0.038).ConclusionsThe results provide a high level of evidence that humoral immunity influences the survival outcomes of patients with early breast cancer, in particular of those with TNBC.Trial registrationThe study reports retrospective biomarker analyses in the prospective FinHer trial and the prospective HE10/97 trial.ISRCTN76560285. Registered on 18 March 2005.ACTRN12611000506998. Registered on 16 May 2011.

A retrospective analysis of immunohistochemically determined IRF4 (interferon regulating factor 4) expression in a consecutive cohort of 114 ovarian cancer patients

BackgroundTumor-infiltrating lymphocytes influence the prognosis of solid tumors, including ovarian cancer (OC). The immunoregulatory transcription factor (IRF4) is mainly expressed in plasma cells and regulates immunoglobulin class switch recombination as well as plasma cell differentiation. Therefore, we analyzed the impact of IRF4 expression in a consecutive cohort of OC patients.MethodsIRF4 expression was evaluated by immunostaining. Differences in IRF4 expression among the subgroups of the established clinical−pathological features like age, histological subtype, tumor stage, histological grading, postoperative tumor burden, and completeness of chemotherapy were determined by χ2 test. The impact of IRF4 expression on progression-free survival (PFS) and overall survival (OS) was examined by univariate and multivariate Cox analysis adjusted for established clinical−pathological factors and Kaplan–Meier survival analysis.Results114 patients entered this study. IRF4 was expressed in 51.7% of the entire cohort. 72.3% patients with high-grade serous OC showed IRF4 expression compared to 37.3% patients with a non-high-grade serous OC (p < 0.001). Univariate Cox-regression analysis revealed no prognostic impact of IRF4 expression in terms of PFS (p = 0.35) and OS (p = 0.98). Kaplan–Meier plots failed to show any prognostic impact for PFS (p = 0.35) and OS (p = 0.98), too. Established clinical–pathological factors retained their prognostic impact as tumor stage in terms of PFS (< 0.001) and as postoperative residual tumor burden (p = 0.04), tumor stage (< 0.001), histological grade (p = 0.02), and completeness of chemotherapy (p < 0.001) in terms of OS, respectively.ConclusionImmunohistochemically determined IRF4 expression correlated with high-grade serous OC. However, it failed to show any prognostic impact in this cohort of 114 patients.

Abstract P2-08-07: Prognostic significance of immune checkpoint receptors in node-negative breast cancer

Background: Immune checkpoint blockade is increasingly discussed in breast cancer. We examined the prognostic significance of the immune checkpoint receptors cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) and programmed cell death protein 1 (PD-1) in node-negative breast cancer. Methods: Microarray based gene-expression data for CTLA-4 (221331_x_at) and PD-1 (207634_at) were analysed in four previously published cohorts (Mainz, Rotterdam, Transbig, Yu) of node-negative breast cancer patients not treated with adjuvant therapy (n=824). A meta-analysis of previously published cohorts was performed using a random effects model. Prognostic significance of CTLA-4 as well as PD-1 for metastasis-free survival (MFS) was examined in the whole cohort and in different molecular subtypes: luminal (ER + /HER2 - ), basal-like (ER - /HER2 - ) and HER2 + . Independent prognostic relevance was analysed using multivariate Cox regression. Results: Higher RNA expression of CTLA-4 was related to better MFS in a meta-analysis of the whole cohort (HR 0.58, 95% CI 0.38-0.88, P=0.0102). Prognostic significance was most pronounced in the HER2 + positive molecular subtype (HR 0.23, 95% CI 0.08-0.65, P=0.0062) as compared to luminal (HR 0.68, 95% CI 0.39-1.18, P=0.1744) and basal-like (HR 0.53, 95% CI 0.25-1.15), P=0.1087) carcinomas of the breast. PD-1 RNA expression, however, was not associated with outcome in the whole cohort of patients (HR 0.88, 95% CI 0.32-2.43, P=0.1853). A trend for improved survival was noticed in basal-like breast cancer (HR 0.40, 95% CI 0.15-1.08, P=0.0701). Neither luminal (HR 0.81, 95% CI 0.28-2.36, P=0.2122) nor HER2 + (HR 0.85, 95% CI 0.27-2.68, P=0.7759) patients showed an association of PD-1 with MFS. CTLA-4 showed independent prognostic significance (HR 0.393, 95% CI 0.224-0.688, P=0.001) in multivariate analysis. In addition to CTLA-4, only histological grade of differentiation (HR 2.335, 95% CI 1.490-3.660, P Conclusions: The immune checkpoint receptor CTLA-4 has independent prognostic significance in node-negative breast cancer. Higher expression of CTLA-4 is associated with improved outcome. The prognostic impact of CTLA-4 differs between molecular subtypes and is most pronounced in HER2 + breast cancer. Citation Format: Schmidt M, van de Sandt L, Heimes A-S, Battista M, Lebrecht A, Almstedt K, Hoffmann G, Rahnenfuhrer J, Hengstler JG. Prognostic significance of immune checkpoint receptors in node-negative breast cancer. [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 P2-08-07.