Heike Loeser

Dr. Heike Loeser

Insitute of Pathology, University Hospital of Cologne
orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
27 February 2019 in OncoImmunology
Verified
Journal Article
Open access
HLHeike Loeser
Heike Loeser
MKMax Kraemer
Max Kraemer
FGFlorian Gebauer
Florian Gebauer
CBChristiane Bruns
Christiane Bruns
WSWolfgang Schröder
Wolfgang Schröder
AQAlexander Quaas
Alexander Quaas
Immune checkpoint modulation in cancer has been demonstrated as a high-value therapeutic strategy in many tumor entities. VISTA is an immune checkpoint receptor regulating T-cell function. To the best of our knowledge, nothing is known about the expression and prognostic impact of VISTA on tumor infiltrating lymphocytes (TILs) in the tumor microenvironment of esophageal adenocarcinoma (EAC). We analyzed in total 393 EACs within a test-cohort (n = 165) and a validation-cohort (n = 228) using a monoclonal antibody (clone D1L2G). These data were statistically correlated with clinical as well as molecular data. 22.2% of the tumor cohort presented with a VISTA expression on TILs. These patients demonstrated an improved median overall survival compared to patients without VISTA expression (202.2 months vs. 21.6 months; p < 0.0001). The favorable outcome of VISTA positive tumors is significant in the entire cohort but mainly driven by the general better prognosis of T1/T2 tumors. However, in the pT1/2 group, VISTA positive tumors show a tremendous survival benefit compared to VISTA negative tumors revealing real long-term survivors in this particular subgroup. The survival difference is independent of the T-stage. This unique characteristic could influence neoadjuvant therapy concepts for EAC, since a profit of therapy could be reduced in the already favorable subgroup of VISTA positive tumors. VISTA emerges as a prognostic biomarker for long-term survival especially in the group of early TNM-stages. Future studies have to show the relevance of VISTA positive TILs within a tumor concerning response to specific immune checkpoint inhibition.

8 January 2019 in BMC Cancer
Verified
Journal Article
Open access
PDF file
PPPatrick Sven Plum
Patrick Sven Plum
FGFlorian Gebauer
Florian Gebauer
MKMax Krämer
Max Krämer
HAHakan Alakus
Hakan Alakus
FBFelix Berlth
Felix Berlth
HLHeike Loeser
Heike Loeser
HER2 (ERBB2 or HER2/neu) is a tyrosine-kinase increasing cell proliferation. Overexpression/amplification of HER2 is correlated with worse prognosis in solid malignancies. Consequently, HER2 targeting is established in breast and upper gastrointestinal tract cancer. There are conflicting data concerning the impact of HER2 overexpression on esophageal adenocarcinoma (EAC), as most studies do not differ between cancers of the esophagus/gastroesophageal junction and the stomach. The aim of this study was to analyze the expression/amplification of HER2 in EAC in correlation to clinicopathological data to verify its prognostic impact. We analyzed 428 EAC patients that underwent transthoracic thoraco-abdominal esophagectomy between 1997 and 2014. We performed HER2 immunohistochemistry (IHC) according to the guidelines and fluorescence-in-situ-hybridization (FISH) for IHC score2+, using tissue micro arrays (TMA) with up to eight biopsies from the surface and infiltration area of a single tumor for evaluating HER2-heterogeneity and single-spot TMA. The HER2-status was correlated with clinicopathological data. HER2-positivity was found in up to 14.9% in our cohort (IHC score 3+ or IHC score 2+ with gene amplification) and demonstrated a significantly better overall survival (OS) in correlation to HER2-negative tumors (median OS 70.1 vs. 24.6 months, p = 0.006). HER2-overexpression was more frequently seen in lower tumor stages (pT1/pT2, p = 0.038), in the absence of lymphatic metastases (pN0/pN+, p = 0.020), and was significantly associated with better histological grading (G1/G2) (p = 0.041). We demonstrated a positive prognostic impact of HER2 overexpression in a large cohort of EAC, contrary to other solid malignancies including gastric cancer and breast cancer, but consistent to the results of a large study on EAC from 2012.

1 February 2020 in Translational Oncology
Verified
Journal Article
Open access
AEAhlem Essakly
Ahlem Essakly
HLHeike Loeser
Heike Loeser
MKMax Kraemer
Max Kraemer
HAHakan Alakus
Hakan Alakus
SCSeung-Hun Chon
Seung-Hun Chon
AQAlexander Quaas
Alexander Quaas
Gene amplifications of PIK3CA or KRAS induce a downstream activation of the AKT-mTOR or RAF-ERK-pathways. Interactions of the active AKT pathway have been implicated in the inflammatory tumor microenvironment. Nothing is known about these interactions or prognostic power in esophageal adenocarcinoma (EAC). We retrospectively analyzed a large cohort of 685 EAC considering KRAS and PIK3CA gene amplification using fluorescence in situ hybridization (FISH) and immunohistochemistry. These results were correlated with clinical and molecular data as well as the inflammatory tumor microenvironment. Amplifications of KRAS were seen in 94 patients (17.1%), PIK3CA amplifications in 23 patients (5.0%). KRAS amplifications significantly correlated with nodal positive patients and poorer overall survival (OS) in the subgroup without neoadjuvant treatment (p = 0.004), coamplifications of Her2 (p = 0.027), and TP53 mutations (p = 0.016). PIK3CA amplifications significantly correlated with a high amount of tumor infiltrating T cells (p = 0.003) and showed a tendency to better OS (p = 0.068). A correlation with checkpoint makers (PD-L1, LAG3, VISTA, TIM3, IDO) could not be revealed. Our findings are the first to link the KRAS amplified genotype with lymphonodal positivity and poor prognosis and the PIK3CA-amplified genotype with a T cell-rich microenvironment in EAC. Future studies must show whether these two genotype subgroups can be therapeutically influenced. A dual inhibition of MEK and SHP2T could be effective in the subgroup of KRAS amplified EACs and an immune checkpoint blockade may prove to be particularly promising in the subgroup of PIK3CA-amplified EACs.

1 September 2013 in Cardiovascular Pathology
Verified
Journal Article
Closed access
HLHeike Loeser
Heike Loeser
MWMaike Wittersheim
Maike Wittersheim
KPKatharina Puetz
Katharina Puetz
JFJohannes Friemann
Johannes Friemann
RBReinhard Buettner
Reinhard Buettner
JFJochen W.U. Fries
Jochen W.U. Fries

30 June 2020 in Cancers
Verified
Journal Article
Open access
PDF file
HLHeike Loeser
Heike Loeser
CWChristina Wölwer
Christina Wölwer
HAHakan Alakus
Hakan Alakus
SCSeung-Hun Chon
Seung-Hun Chon
TZThomas Zander
Thomas Zander
AQAlexander Quaas
Alexander Quaas
Background: The loss of the Y chromosome in various malignant diseases has been described previously. There are no reliable information on the actual frequency, significance and homogeneity of Y chromosome loss (LoY) in esophageal adenocarcinoma (EAC). Methods: 400 male EAC including lymph-node metastases were analyzed with commercially available Y chromosome specific fluorescence in-situ probes. The results were correlated with molecular and immunohistochemical markers and clinicopathological aspects. Results: The entire cohort (n = 400) showed a singular LoY of one chromosome arm in 1.0% (q-arm) and 2.8% (p-arm), complete LoY in 52.5%. LoY was strongly associated with shortened overall-survival (OS). Patients with preserved Y chromosome had a median OS of 58.8 months, patients with LoY an OS of 19.4 months (p < 0.001). Multivariate analysis showed LoY as an independent prognostic marker with a hazard ratio of 1.835 (95% CI 1.233–2.725). LoY correlated with TP53 mutations (p = 0.003), KRAS amplification (p = 0.004), loss of ARID1a (p = 0.045) and presence of LAG3 (p = 0.018). Conclusions: Loss of the Y chromosome is a very common phenomenon in EAC. The LoY is heterogeneously distributed within the tumor, but corresponding lymph node metastases frequently show homogeneous LoY, indicating a selection and metastasizing advantage with poor prognosis. To date, the male predominance of EAC (7–9:1) is unclear, so genetic explanatory models are favored. The LoY in EAC may be biologically and functionally relevant and additional genomic or functional analyses are needed.

29 May 2021 in Cancers
Verified
Journal Article
Open access
PDF file
FPFelix Popp
Felix Popp
ICIngracia Capino
Ingracia Capino
JBJoana Bartels
Joana Bartels
ADAlexander Damanakis
Alexander Damanakis
JLJiahui Li
Jiahui Li
OGon behalf of the PANCALYZE Study Group
on behalf of the PANCALYZE Study Group
Pancreatic cancer features elaborate mechanisms of immune evasion. The potential of new immune molecules was explored to restore the antitumor immune response. If these immune molecules are associated with poor survival, specific drugs could take effect. Here, we analyze the expression of VISTA, LAG3, IDO, and TIM3 on tumor-infiltrating lymphocytes (TILs) and its impact on patient survival. We analyzed 153 pancreatic cancer patients from the prospectively managed database of the multicentered PANCALYZE study. Immunohistochemistry on a tissue microarray assessed VISTA, LAG3, IDO, and TIM3 expression of TILs from the patients undergoing primary resection. Complementarily, we analyzed publicly available transcriptomic data (n = 903). Successful completion of chemotherapy, and lymph node status were independent predictors of survival in the multivariate analysis of the clinicopathologic parameters. Fifteen tumors were exclusively VISTA-positive, thirteen tumors expressed VISTA together with TIM3, and ten tumors expressed VISTA together with IDO. Patients featuring tumors with high numbers of IDO-positive TILs had better patient survival (p = 0.037). VISTA, LAG3, and TIM3 expression did not correlate with survival. The analysis of publicly available data did not show survival differences. Tumors rarely co-express more than two immune molecules at the same time, and VISTA is most frequently co-expressed. Although IDO generally inhibits T-cell proliferation, a high expression of IDO was associated with improved survival. We expect immune checkpoint inhibitors against VISTA, LAG3, and TIM3 to be inefficient in a clinical application.