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Y. Zhou
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P3.02 - Poster Session/ Treatment of Localized Disease – NSCLC (ID 211)
- Event: WCLC 2015
- Type: Poster
- Track: Treatment of Localized Disease - NSCLC
- Presentations: 1
- Moderators:
- Coordinates: 9/09/2015, 09:30 - 17:00, Exhibit Hall (Hall B+C)
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P3.02-004 - PD-L1 Overexpression in NSCLC Inversely Correlated with Survival of NSCLC Patients (ID 1100)
09:30 - 09:30 | Author(s): Y. Zhou
- Abstract
Background:
Programmed cell death protein 1, also known as PD1, is a 288 amino acids cell surface protein in the immunoglobulin superfamily. [[1]] PD-1 is expressed on T-cells and pro-B cells, plays a pivotal role in their differentiation. [[2]] PD-1 has two ligands, PD-L1 and PD-L2, which are the members of a peripheral membrane protein family called B7. [[3][4]] PD-L1 can suppress immune system in some special events such as pregnancy and auto immune disease. Binding of PD-L1 with its receptor PD-1 on T cells delivers a signal that inhibits TCR-mediated activation of IL-2 production and T cell proliferation. [[5]] PD-L2’s expression is more restricted compare to PD-L1 and mainly in antigen-presenting cells like Dendritic Cells and microphages. [[4]] Here we report a study of 139 NSCLC patients diagnosed and undergone primary surgery in Shanghai Chest Hospital. The expression of PD-L1 was exanimated by immunohistochemistry, and has a positive correlation with the stage of NSCLC. We also observed a significant correlation between PD-L1 over expression and EGFR mutation, which has the potential to be an favorable prognostic factor. High PD-L1 expression and EGFR mutation also correlated with a significant longer survival time of patients
Methods:
One pathologist examined the H&E- and IHC-stained slides and evaluated the results. The evaluation were done blinded as to the clinical pathologic characteristics and patient outcome. A series of 139 patients diagnosed with NSCLC and undergone primary surgery at Shanghai Chest Hospital (Shanghai, China) from January to December of 2008 were selected in this study. All the patients received lobectomy standard with systematic lymph node dissection. Immunohistochemistry staining for PD-L1 were performed both for tumor and tissue surrounding the tumor.PD-L1 positivity (PDL1+) was defined as 5% tumor cell membrane staining at any intensity.One pathologist examined the H&E- and IHC-stained slides and evaluated the results. The evaluation were done blinded as to the clinical pathologic characteristics and patient outcome. Overall survival data were obtained for each patient by following up visit performed on 2014.
Results:
A total of 139 tumors were examined after exclusion of uninformative slides. There were 72 patients (54.1 %) with stage II, and 61 (45.9 %) with stage III disease. For histological subtypes, there were 90 with adenocarcinoma, 43 with square carcinoma, and 6 with others. Of these, positive evaluation of PD-L1 staining was present in 81 (61.8 %) specimens, while 50 ( 38.2 %) specimens showed negtive/low PD-L1 staining, while the tumor adjacent tissue showed also negtive/low PD-L1 expression .We also did genotyping for the specimens and found about one third of them (50 in a total 133 specimens, 33.3%) carry EGFR mutation. Among the mutations,15 are happened on exome 19 and 33 are on exome 21. PD-L1 positively expression imply a longer survival time compared with PD-L1negatively expression.
Conclusion:
Our results suggest a prognostic value of PD-L1 expression evaluation, which can also be a potentiall immuno-target therapy for lung cancer
