Abstract 4071
Background
Test for the human epidermal growth factor receptor 2 (HER2) expression is an essential step to select gastric cancer patients for HER2 molecular targeted therapy. Peritoneal carcinomatosis with ascites is the most common manifestation of gastric cancer metastases, prevalence upto 40% in previous reports. The aim of this study is to compare the HER2 expression status in primary gastric adenocarcinoma and paired cell block of malignant ascites.
Methods
Forty-five patients with evaluable tissue samples of both primary gastric lesion and ascites cell block were enrolled. HER2 expression status was evaluated by immunohistochemistry (IHC) in primary tumor and in paired cell blocks of ascites which was confirmed by the qualified pathologist.
Results
HER2 expression was detected in 16 patients (35.6%) from primary gastric adenocarcinoma tissue and in 10 (22.2%) from ascites cell block. HER2 overexpression defined by IHC 3+ was observed in 2 (4.4%) and 3(6.7%) of primary lesion and ascites samples, respectively. However the HER2 status of primary tumor and ascites cell block showed discordance in all of those patients with HER2 overexpression. Patients with HER2 overexpression in primary gastric tissue showed HER2 negativity in ascites cell block, and vise versa. Of the 14 patients whom with two or more serial ascites samples, the HER2 IHC score differences between the samples were observed in five patients (35.7%).
Conclusions
Incidence of HER2 overexpression was slightly lower than previous reports in primary gastric tumor and metastatic ascites samples in this study. Discordances of HER2 expression status between the primary gastric adenocarcinoma and ascites cell block or between serially sampled ascites were observed in a significant proportion of the patients (20%). HER2 testing from both primary tumor and ascites cell block and from serial ascites sample could increase the sensitivity of HER2 overexpression detection, and assist to select adequate patients for HER2 molecular targeted therapy.
Clinical trial identification
Legal entity responsible for the study
Chungbuk National University Hospital.
Funding
Chungbuk National University Hospital.
Editorial Acknowledgement
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
1978 - FAM115c that upregulates proliferation and invasion under hypoxia could be a predictive biomarker for pancreatic cancer.
Presenter: Kiyoshi Saeki
Session: Poster display session: Basic science, Endocrine tumours, Gastrointestinal tumours - colorectal & non-colorectal, Head and neck cancer (excluding thyroid), Melanoma and other skin tumours, Neuroendocrine tumours, Thyroid cancer, Tumour biology & pathology
Resources:
Abstract
3682 - Pathologic assessment following neoadjuvant immunotherapy or chemotherapy demonstrates similar patterns in non-small cell lung cancer (NSCLC)
Presenter: Annikka Weissferdt
Session: Poster display session: Basic science, Endocrine tumours, Gastrointestinal tumours - colorectal & non-colorectal, Head and neck cancer (excluding thyroid), Melanoma and other skin tumours, Neuroendocrine tumours, Thyroid cancer, Tumour biology & pathology
Resources:
Abstract
3319 - Tumor-infiltrating CD3+ lymphocytes and ICOS+ T-cells predict a favorable survival in resected esophageal squamous cell carcinoma
Presenter: Min Hee Hong
Session: Poster display session: Basic science, Endocrine tumours, Gastrointestinal tumours - colorectal & non-colorectal, Head and neck cancer (excluding thyroid), Melanoma and other skin tumours, Neuroendocrine tumours, Thyroid cancer, Tumour biology & pathology
Resources:
Abstract
5130 - Chemokine receptor CXCR7 expression, function and clinical implications in head and neck squamous cell carcinoma
Presenter: Myung-Won Lee
Session: Poster display session: Basic science, Endocrine tumours, Gastrointestinal tumours - colorectal & non-colorectal, Head and neck cancer (excluding thyroid), Melanoma and other skin tumours, Neuroendocrine tumours, Thyroid cancer, Tumour biology & pathology
Resources:
Abstract
4483 - Assessment of PD-1/PD-L1 colocalization in hepatocellular carcinoma (HCC) using bright-field double labeling and quantitative digital image analysis
Presenter: Thomas Mrowiec
Session: Poster display session: Basic science, Endocrine tumours, Gastrointestinal tumours - colorectal & non-colorectal, Head and neck cancer (excluding thyroid), Melanoma and other skin tumours, Neuroendocrine tumours, Thyroid cancer, Tumour biology & pathology
Resources:
Abstract
1175 - Pulmonary tumor thrombotic microangiopathy (PTTM): 24 case series and its criteria for pathological diagnosis.
Presenter: Naoko Sato
Session: Poster display session: Basic science, Endocrine tumours, Gastrointestinal tumours - colorectal & non-colorectal, Head and neck cancer (excluding thyroid), Melanoma and other skin tumours, Neuroendocrine tumours, Thyroid cancer, Tumour biology & pathology
Resources:
Abstract
1359 - Autofluorescence: a new marker for identifying cancer stem cells (CSCs) in primary tumors
Presenter: Miriam López Gómez
Session: Poster display session: Basic science, Endocrine tumours, Gastrointestinal tumours - colorectal & non-colorectal, Head and neck cancer (excluding thyroid), Melanoma and other skin tumours, Neuroendocrine tumours, Thyroid cancer, Tumour biology & pathology
Resources:
Abstract
2651 - NACC1 as a target of microRNA-331-3p regulates cell proliferation in urothelial carcinoma cells
Presenter: Kohei Morita
Session: Poster display session: Basic science, Endocrine tumours, Gastrointestinal tumours - colorectal & non-colorectal, Head and neck cancer (excluding thyroid), Melanoma and other skin tumours, Neuroendocrine tumours, Thyroid cancer, Tumour biology & pathology
Resources:
Abstract
2233 - Somatic-stem transition of tumor cells is a key link in the metastasis
Presenter: Nicolai Litviakov
Session: Poster display session: Basic science, Endocrine tumours, Gastrointestinal tumours - colorectal & non-colorectal, Head and neck cancer (excluding thyroid), Melanoma and other skin tumours, Neuroendocrine tumours, Thyroid cancer, Tumour biology & pathology
Resources:
Abstract
2601 - Profile of individuals who never undergo colorectal cancer screening
Presenter: Jérôme Viguier
Session: Poster display session: Basic science, Endocrine tumours, Gastrointestinal tumours - colorectal & non-colorectal, Head and neck cancer (excluding thyroid), Melanoma and other skin tumours, Neuroendocrine tumours, Thyroid cancer, Tumour biology & pathology
Resources:
Abstract