Conclusions
The combined detection of the HER2 gene and PD-1/PD-L1 in gastric cancer provides an important reference index for the prognosis of gastric cancer and the benefit of targeted antitumor drugs.
Methods
Immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) were used to detect HER2 protein expression, HER2 gene amplification, and PD-1/PD-L1 expression in 78 cases of gastric cancer.
Objective
To explore the relationship between the HER2 gene and PD-1/PD-L1 in gastric cancer and its significance.
Results
The expression rate of HER2 protein was 43.6% (34/78), of which 19.4% (14/78) were HER2 3+, 14.1% (11/78) were HER2 2+, and 11.5% (9/78) were HER2 1+. The results showed that 19.2% (15/78) of samples had HER2 gene amplification, 3.8% (3/78) of samples had a HER2/CEP17 ratio <2.0, and 19.2% (15/78) of samples had HER2 gene amplificationf and HER2 copy/cell ≥6.0, as detected by FISH. The positive rate of PD-L1 was 38.5% (30/78) in gastric cancer cells and 50.0% (39/78) in interstitial lymphocytes. The expression of the HER2 gene, PD-L1, and PD-1 in gastric cancer was correlated with the stage and lymph node metastasis of gastric cancer (P < 0.05). Conclusions: The combined detection of the HER2 gene and PD-1/PD-L1 in gastric cancer provides an important reference index for the prognosis of gastric cancer and the benefit of targeted antitumor drugs.