We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Change in PD-L1 Expression After Acquiring Resistance to Gefitinib in EGFR-Mutant Non-Small-Cell Lung Cancer.
- Authors
Jae Joon Han; Dong-Wan Kim; Jaemoon Koh; Bhumsuk Keam; Tae Min Kim; Yoon Kyung Jeon; Se-Hoon Lee; Doo Hyun Chung; Dae Seog Heo; Han, Jae Joon; Kim, Dong-Wan; Koh, Jaemoon; Keam, Bhumsuk; Kim, Tae Min; Jeon, Yoon Kyung; Lee, Se-Hoon; Chung, Doo Hyun; Heo, Dae Seog
- Abstract
<bold>Introduction: </bold>Therapies targeting programmed cell death-1 (PD-1) and its ligand (PD-L1) have been successful in a subset of patients with non-small-cell lung cancer (NSCLC). PD-L1 expression in tumor tissues has been suggested as a predictive and prognostic marker. We examined the change in PD-L1 expression after gefitinib in patients with EGFR-mutant NSCLC.<bold>Materials and Methods: </bold>Paired tumor tissues were collected before and after gefitinib from 18 patients. PD-L1 expression on the tumor and immune cells was defined by the H-score of immunohistochemical staining (range, 0-300). The correlations between the change in PD-L1 expression and clinicopathologic characteristics were analyzed.<bold>Results: </bold>PD-L1 expression on tumor cells showed an increase in the median H-score from 25 to 40 (P = .067). Of the 18 patients, 7 (38.9%) had a marked increase in the median H-score (range, 80-180; group A) and 11 (61.1%) had no change in the median H-score (0 for both scores; group B). In groups A and B, the median progression-free survival for gefitinib was 13 and 12 months (P = .594), and the median overall survival was "not reached" and 38 months (P = .073), respectively. MET positivity by immunohistochemistry in biopsies after gefitinib therapy was significantly associated with group A (P = .028). The PD-L1 H-score by immunohistochemistry, but not by tumor cells, showed correlations with other immune cells; FOXP3(+) expression in biopsies before gefitinib use, and PD-1(+) and CD3(+) in biopsies after gefitinib therapy, respectively.<bold>Conclusion: </bold>PD-L1 expression in tumor cells markedly increased in a subset of patients after gefitinib treatment. Thus, rebiopsy should be considered when using PD-L1 expression as a biomarker.
- Publication
Clinical Lung Cancer, 2016, Vol 17, Issue 4, p263
- ISSN
1525-7304
- Publication type
journal article
- DOI
10.1016/j.cllc.2015.11.006