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Optimized PD-L1 scoring of gastric cancer
- Source :
- Gastric Cancer
- Publication Year :
- 2021
-
Abstract
- Background PD-1/PD-L1-Immunotherapy has been approved for gastric carcinoma. PD-L1 assessment by immunohistochemistry is the principle biomarker. Are biopsies able to map the actual PD-L1 status of the entire tumor? Methods Whole tumor slides of 56 gastric carcinoma were analyzed to determine the distribution of PD-L1 positive cells in the entire tumor areas. Tissue micro arrays with four cores of the tumor surface, which represents the endoscopically accessible biopsy zone, were built from the same tumors. The PD-L1 CPS value was determined separately for each core. Preoperative diagnostic biopsies were available for 22 of the tumors. PD-L1 prevalence, sensitivity and specificity were analyzed using the whole tumor slides as reference scores. Molecular subtyping was performed and related to the PD-L1 status. Results 27.3% of cases were PD-L1 negative (CPS The biopsies showed best test characteristics if four surface biopsies were analyzed combined, i.e., the CPS was calculated across all four biopsies. The prevalence showed a distribution similar to the resection specimens, sensitivity was 0.73 and specificity 1.0. Using fewer surface biopsies decreased sensitivity and specificity and caused false-negative classifications. Compared to the TMAs, the preoperative biopsies showed reduced sensitivity (0.412). Conclusions This is the first comprehensive study to optimize PD-L1 assessment in gastric cancer using endoscopically available tissue. The obtained PD-L1 prevalence is consistent with data of current clinical studies. Calculation of the test characteristics shows that surface biopsies can be indicative of the true PD-L1 status based on the resection specimen. However, an adequate number of biopsies is required. In this study, n = 4 biopsies yielded best results.
- Subjects :
- PD-L1
Cancer Research
Biopsy
B7-H1 Antigen
Surgical oncology
Stomach Neoplasms
Checkpoint inhibition
medicine
Biomarkers, Tumor
Humans
Biopsies
medicine.diagnostic_test
biology
business.industry
Gastroenterology
Cancer
Endoscopically obtained
General Medicine
Biomarker
medicine.disease
Immunohistochemistry
Oncology
Decreased Sensitivity
biology.protein
Biomarker (medicine)
Original Article
Nuclear medicine
business
Gastric cancer
Abdominal surgery
Subjects
Details
- ISSN :
- 14363305
- Volume :
- 24
- Issue :
- 5
- Database :
- OpenAIRE
- Journal :
- Gastric cancer : official journal of the International Gastric Cancer Association and the Japanese Gastric Cancer Association
- Accession number :
- edsair.doi.dedup.....789cf905126a419861a7a737db1744f3