In:
Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 35, No. 15_suppl ( 2017-05-20), p. 8516-8516
Abstract:
8516 Background: Conflicting data exists on the potential prognostic impact of PD-L1 expression in NSCLC. The Lungscape project, a fully annotated large biobank of resected stage I-III NSCLC, allows detailed analysis of this issue. Methods: Prevalence of PD-L1 positivity and its association with clinicopathological characteristics and patient outcome - Relapse-free Survival (RFS), Time-to-Relapse (TTR) and Overall Survival (OS) - was explored in the ETOP Lungscape cohort. PD-L1 expression was assessed on tissue microarrays (TMAs) using the DAKO 28-8 immunohistochemistry assay. Positivity cut-off points of ≥1%, 5% and 50% for neoplastic cell membrane staining were considered. Results: PD-L1 data were available for 2182 patients, from 15 ETOP centers, with median follow-up 4.8 years; 1191 patients still alive; median age 66 years; 64% male, 32/54/11% for current/former/never smokers; 49/29/22% for stages I/II/III; 51/42/4/3% adenocarcinomas (AC)/squamous cell (SCC) /large cell and sarcomatoid (LCS)/other. Median RFS/TTR/OS were 53/99/69 months (AC: 52/84/72, SCC: 54/not reached/64; and LSC 52/103/74). PD-L1 prevalence with 1% cut-off was, overall: 43%, 95% confidence interval (95%CI): 41-46; (AC: 42%, 95%CI: 39-46; SCC: 44%, 95%CI: 40-47; and LCS: 53%, 95%CI: 42-65), while for 5% threshold, prevalence was 34%, 95%CI: 32-36. PD-L1 1% positivity was a significant predictor only for AC: HR RFS: + vs - = 0.82; 95%CI: 0.69-0.97, HR TTR: + vs - = 0.83; 95%CI: 0.68-1.01, HR OS: + vs - = 0.83; 95%CI: 0.69-1.01 (adjusted p = 0.024, 0.064, 0.063 respectively). This effect is found also for the 5% cut-off, and preserved in the overall model including all histologies. Using the 50% cut-off, PD-L1 positivity was detected in 17% of patients; 95%CI: 15-18, but was no longer a significant predictor of outcome, overall and by histology type. Conclusions: PD-L1 positivity (1% and 5% cut-offs) was present in more than one third of resected NSCLC and was associated with a better prognosis for AC patients.
Type of Medium:
Online Resource
ISSN:
0732-183X
,
1527-7755
DOI:
10.1200/JCO.2017.35.15_suppl.8516
Language:
English
Publisher:
American Society of Clinical Oncology (ASCO)
Publication Date:
2017
detail.hit.zdb_id:
2005181-5
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