From the Guidelines
The incidence of gastric cancer with PD-L1 expression levels of 1-5% is not explicitly stated in the provided evidence, but it is known that PD-L1 expression is present in approximately 30-65% of gastric cancer cases, with varying levels of expression. The provided evidence does not directly answer the question regarding the incidence of gastric cancer with PD-L1 expression levels of 1-5%. However, it discusses the importance of PD-L1 expression in gastric cancer and its implications for treatment.
- PD-L1 (Programmed Death-Ligand 1) is a protein that helps cancer cells evade immune detection, and its expression in gastric cancer has important clinical implications 1.
- Patients with PD-L1-positive gastric cancer may benefit from immune checkpoint inhibitors like pembrolizumab (Keytruda) or nivolumab (Opdivo), which target the PD-1/PD-L1 pathway 1.
- The FDA has approved pembrolizumab for PD-L1-positive recurrent locally advanced or metastatic gastric/gastroesophageal junction adenocarcinoma with Combined Positive Score (CPS) ≥1 1.
- Testing for PD-L1 expression should be performed using validated immunohistochemistry assays 1.
- Nivolumab is a monoclonal PD-1 antibody that was approved by the FDA in combination with fluoropyrimidine- and platinum-based chemotherapy for the first-line treatment of patients with advanced or metastatic gastric cancer 1. It is essential to note that the provided evidence focuses on the treatment of gastric cancer with PD-L1 expression, rather than the incidence of PD-L1 expression levels of 1-5%.
- The evidence suggests that PD-L1 expression is a crucial biomarker in gastric cancer, and its detection can help identify patients who may benefit from immunotherapy 1.
- The treatment of gastric cancer with PD-L1 expression involves the use of immune checkpoint inhibitors, such as pembrolizumab and nivolumab, in combination with chemotherapy 1.
From the Research
Incidence of Gastric Cancer with PD-L1 Expression Levels of 1-5%
- The study 2 found that about 37.3% of gastric cancer cases showed PD-L1 expression in tumor cells and/or tumor-infiltrating immune cells, with 17.3% showing PD-L1 expression in tumor cells and 34.5% in tumor-infiltrating immune cells.
- The same study 2 reported that cases with at least 1% membranous and/or cytoplasmic PD-L1 staining in either tumor cells or tumor-infiltrating immune cells were considered as PD-L1 positive.
- Another study 3 found that 66.7% of gastric cancer samples were positive for PD-L1 with a combined positive score (CPS) ≥ 1.
- However, none of the studies provided a specific incidence of gastric cancer with PD-L1 expression levels of 1-5%, as the studies either reported the percentage of PD-L1 positive cases or the correlation between PD-L1 expression and clinicopathologic variables.
PD-L1 Expression and Gastric Cancer
- The study 4 discussed the importance of accurate interpretation of PD-L1 combined positive score (CPS) in gastric cancer, especially at a cutoff of 5, for predicting response to anti-programmed death 1/PD-L1 agents.
- The study 5 found that PD-L1 expression was significantly elevated in elderly patients with gastric cancer, with 38.1% of patients aged 70 or older having a combined positive score ≥ 1, compared to 21.5% of patients under 70.
- The study 6 reviewed the biological mechanism, function, and immunotherapy of PD-L1 in gastric cancer, highlighting the potential of PD-L1/PD-1 inhibitors in treating the disease.