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- Ellegård, Sander, et al.
(författare)
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ERBB2 and PTPN2 gene copy numbers as prognostic factors in HER2-positive metastatic breast cancer treated with trastuzumab
- 2019
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Ingår i: Oncology Letters. - Athens, Greece : Spandidos Publications. - 1792-1074 .- 1792-1082. ; 17:3, s. 3371-3381
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Tidskriftsartikel (refereegranskat)abstract
- Trastuzumab has markedly improved the treatment and long-term prognosis of patients with HER2-positive breast cancer. A frequent clinical challenge in patients with relapsing and/or metastatic disease is de novo or acquired trastuzumab resistance, and to date no predictive biomarkers for palliative trastuzumab have been established. In the present study, the prognostic values of factors involved in the HER2-associated PI3K/Akt signalling pathway were explored. The first 46 consecutive patients treated at the Department of Oncology, Linkoping University Hospital between 2000 and 2007 with trastuzumab for HER2-positive metastatic breast cancer were retrospectively included. The gene copy number variation and protein expression of several components of the PI3K/Akt pathway were assessed in the tumour tissue and biopsy samples using droplet digital polymerase chain reaction and immunohistochemistry. Patients with tumours displaying a high-grade ERBB2 (HER2) amplification level of amp;gt;= 6 copies had a significantly improved overall survival hazard ratio [(HR)=0.4; 95%, confidence interval (CI): 0.2-0.9] and progression-free survival (HR=0.3; 95% CI: 0.1-0.7) compared with patients with tumours harbouring fewer ERBB2 copies. High-grade ERBB2 amplification was significantly associated with the development of central nervous system metastases during palliative treatment. Copy gain (amp;gt;= 3 copies) of the gene encoding the tyrosine phosphatase PTPN2 was associated with a shorter overall survival (HR=2.0; 95% CI: 1.0-4.0) and shorter progression-free survival (HR=2.1; 95% CI: 1.0-4.1). In conclusion, high ERBB2 amplification level is a potential positive prognostic factor in trastuzumab-treated HER2-positive metastatic breast cancer, whereas PTPN2 gain is a potential negative prognostic factor. Further studies are warranted on the role of PTPN2 in HER2 signalling.
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- Ellegård, Sander, 1985-
(författare)
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HER2-positive breast cancer : Clinical and molecular aspects
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- BackgroundHuman Epidermal Growth Factor Receptor 2 (HER2)-positive breast cancer is notable for its aggressive behavior, however with the introduction of trastuzumab in the early 2000’s, prognosis has improved. This thesis investigates the efficacy of trastuzumab in real-world settings after its introduction and evaluates the prognostic value of molecular biomarkers, aiming to optimize treatment approaches and improve patient outcomes.Material and MethodsHER2-positive patients treated in the advanced and early stages of breast cancer were retrospectively identified using Swedish patient registries and through the review of medical records.Study I included 46 patients with advanced breast cancer treated with trastuzumab between 2000 and 2007. Immunohistochemical analysis of several proteins hypothesized to be involved in trastuzumab resistance were evaluated. Additionally, gene copy number variations were analyzed using droplet digital PCR.Study II include 599 patients who received adjuvant trastuzumab between 2006 and 2014 in the Southeastern health care region, in order to evaluate the implementation of trastuzumab after its approval and to evaluate patient outcomes with regard to clinicopathological variables.Study III conducted quantitative analyses of stromal tumor-infiltrating lymphocytes (sTILs) in patients with available tumor material from the same cohort identified in study II. Additionally, a case-control study of 21 cases with 21 matched controls treated with trastuzumab were analyzed with RNA-sequencing in order to identify important differentially expressed genes.ResultsStudy I demonstrated that trastuzumab treatment in a real-world setting had similar survival as in pivotal clinical trials. Additionally, high amplification of HER2 correlated with improved progression-free survival (PFS) and overall survival (OS) in advanced breast cancer patients and PTPN2 gain was correlated with reduced PFS and OS.Study II confirmed trastuzumab's efficacy in a large real-world cohort. Trastuzumab treatment, estrogen receptor (ER) status and number of metastatic lymph nodes were the most important prognostic factors for breast cancer-specific survival and distant recurrence-free survival.Study III identified a significant association between high levels of sTILs and improved overall survival. Additionally, several G-protein coupled receptors (GPCRs) involved in EGFR and Wnt signaling were found to be upregulated in cases vs controls.ConclusionsTrastuzumab maintains its efficacy in clinical practice, affirming its role in current treatment regimens for HER2-positive breast cancer. The findings support the prognostic significance of sTILs and suggest HER2-amplification levels as a relevant prognostic factor. We propose PTPN2 and several GPCRs as areas for future research.
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- Hallbeck, Anna-Lotta, 1967-
(författare)
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Studies of transforming growth factor alpha in normal and abnormal growth
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Regulation of growth is of fundamental importance for development of the organism and to maintain health. The induction of cell proliferation and matrix production are influenced by several different signaling systems, most importantly by growth factors.The human HER-family of growth factor ligands and receptors is one of the most studied and, at present, one of the most complex including 4 tyrosine kinase receptors and at least 11 different ligands cooperating in the transfer of signals. The HER-family growth responses are also influenced by other intercellular and extracellular signals, including matrix components, cytokines and hormones mediating e.g. inflammation.HER-1 (EGFR) is one of the best known and most extensively studied growth factor receptors. TGF-alpha is possibly the most potent HER-1 ligand and influences wound healing, epidermal maintenance, gastrointestinal function, lactation, pulmonary function and more. Several studies have shown important regulatory functions for some inflammatory cytokines on TGF-alpha production in white blood cells. HER-1 is widespread in epithelial cells but also in mesenchymal cells such as fibroblasts, osteogenic and chondrogenic cells. Consequently, many tumors arising from these cell types express HER family members and often show TGF-alpha and/or HER activation. Indeed, mammary cancer development has been shown when over expressing both TGF-alpha and HER-2 in mouse mammary cells in vivo.In recent years the first HER-1 and HER-2 inhibitors have come into clinical practice for treatment of breast cancer, lung cancer and gastrointestinal cancers, sometimes with great success. However, more knowledge is needed concerning the inflammatory regulation of HER-family expression including where and how the ligands and receptors cooperate. Therefore we were interested in studying the role of TGF-alpha in normal and abnormal growth.First we showed that the acute inflammatory cytokine IL-6 regulates TGF-alpha expression in U-937-1 monocytoid cells. Secondly, we detected a possible long-term enhancing influence of singledose UVR on HER-1 expression in normal human melanocytes. We continued thirdly by revealing TGF-alpha production concomitant with HER-2 in normal human synovia and release of soluble TGF-alpha into the synovial fluid. Both TGF-alpha and HER-2 production were significantly increased in inflammatory joint conditions, e.g. RA. Fourthly, we demonstrated expression of TGF-alpha, HER-1 and HER-2 in synovial sarcoma cells in culture; the observed HER-2 phosphorylation was dependent on ligand induced HER-1 activation.The presented results indicate that TGF-alpha expression can be enhanced by acute inflammatory cytokine IL-6, possibly contributing to growth stimulatory effects assigned to IL-6 itself.The acute effects of UVR on melanocytes mediate up-regulated steady-state expression of HER-1, constituting a potential target for locally produced TGF-alpha that may induce melanocyte proliferation.TGF-alpha and HER-2 seem to have a role in the maintenance ofsynovial joint tissues. Upregulation of TGF-alpha and HER-2 in inflammatory joint conditions, e.g. RA, represents a novel mechanism for synovial proliferation contributing to joint deterioration.TGF-alpha, HER1 and HER-2 may have a role in synovial sarcoma proliferation; further investigation is needed to evaluate HER-family inhibitors as a possible treatment alternative in this type of cancer.
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