Erschienen in:
01.01.2019 | Original Article
Discordancy and changes in the pattern of programmed death ligand 1 expression before and after platinum-based chemotherapy in metastatic gastric cancer
verfasst von:
Ji Hyun Yang, Hyunho Kim, Sang Young Roh, Myung Ah Lee, Jae Myung Park, Han Hee Lee, Cho Hyun Park, Han Hong Lee, Eun Sun Jung, Sung Hak Lee, Young Joon Lee, Moon Hyung Choi, Okran Kim, In-Ho Kim
Erschienen in:
Gastric Cancer
|
Ausgabe 1/2019
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Abstract
Background
Our goal was to evaluate changes in PD-L1 expression in primary tumours of metastatic gastric cancer before and after chemotherapy.
Methods
We evaluated the PD-L1 expression of 72 patients with primary gastric cancer, before and after palliative first-line platinum-based chemotherapy, between January 2015 and March 2017. The PD-L1 ratio was defined as pre-chemotherapy PD-L1 expression divided by the post-chemotherapy PD-L1 expression.
Results
In 30 patients with PD-L1 negative pre-chemotherapy, 12 (40%) were positive post-chemotherapy; among the 42 patients with PD-L1 positive pre-chemotherapy, 24 (57.1%) were negative post-chemotherapy. The degree of PD-L1 expression decreased from 58.3% before chemotherapy to 41.7% after chemotherapy (P = 0.046). Among patients with complete response/partial response (CR/PR), the degree of PD-L1 expression decreased (P = 0.002), as well as PD-L1 positivity with statistical significance (P = 0.013) after chemotherapy, but not among patients with stable disease/progressive disease (SD/PD). Higher disease control rates (CR/PR/SD) were observed in patients with an elevated PD-L1 ratio (P = 0.043). Patients with a high PD-L1 ratio (> 1) were found to be associated with a better progression-free survival (HR 0.34, 95% CI 0.17–0.67, P = 0.002).
Conclusions
PD-L1 expression can change during chemotherapy. Moreover, changes in patterns of PD-L1 expression might be associated with patient prognosis and response to chemotherapy.