Author of

• 20156

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  P1.07 - Immunology and Immunotherapy (ID 693)

  • Event: WCLC 2017
  • Type: Poster Session with Presenters Present
  • Track: Immunology and Immunotherapy
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/16/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)

  • 22695

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    P1.07-027 - PD-L1 Expression Analysis in African American (AA) and Hispanic Lung Cancer Patients at a Minority-Based Academic Cancer Center (ID 9734)

    09:30 - 09:30  |  Author(s): C. Zhu
    • Abstract

    Background:
    PD-L1 testing has been incorporated into the standard treatment paradigm given recent immunotherapy approvals for metastatic lung cancer (LC). Minority populations are notoriously under-represented in large immunotherapy clinical trials. Thus, we examined PD-L1 expression profiles in a minority-based academic cancer center. Among 989 patients with newly diagnosed LC at Montefiore Medical Center (MMC) from 2014-2015, 330 (33%) were AA and 195 (20%) were Hispanic.
    
    Method:
    Retrospective chart review was conducted to determine PD-L1 expression patterns between 1/1/14-6/19/17 at MMC. PD-L1 testing was performed using 22C3pharmDx IHC and positivity was defined as >/=1%. Chi-squared statistical analysis was performed with SPSS. All statistical tests were two-sided.
    
    Result:
    We identified 92 patients who had PD-L1 testing, with a median age of 66. Based on race, 43 (46.7%) were AA, 20 (21.7%) were White, 20 (21.8%) were Other and 9 (9.8%) were race unknown. Based on ethnicity, 27 (29.3%) were Hispanic, 54 (58.7%) were non-Hispanic and 11 (12%) were ethnicity unknown. Adenocarcinoma was the dominant histology (61%). Nine (9.8%) were EGFR mutant and 1 (1.1%) had an ALK rearrangement. Fresh tissue was used in 50% of cases. PD-L1 TPS >50% was found in 30 (33%), 1-49% in 22 (24%) and <1% in 39 (42%). At time of this analysis, 29 (32%) had received immunotherapy. In the racial analysis, 9 were excluded due to unknown race. Amongst the 43 AA patients, 28 (65%) were PD-L1 positive, and 15 (35%) were negative compared to the 40 non-AA patients which were PD-L1 positive in 20 (50%) and negative in 20 (50%). AAs trended toward increased PD-L1 positivity compared to non-AAs although it was not significant (p=0.163). In the ethnicity analysis, 11 were excluded due to unknown ethnicity. Amongst the 27 Hispanic patients, 11 (40.7%) were PD-L1 positive and 16 (59.3%) were negative compared to the 54 non-Hispanic patients who were PD-L1 positive in 37 (68.5%) and 17 (31.5%) were negative. Analysis suggests there is a negative association between Hispanic ethnicity and positive PD-L1 testing (p=0.016).
    
    Conclusion:
    This is the first known report on PD-L1 expression in AA and Hispanic patient populations. We found that Hispanics had significantly more PD-L1 negative cases compared to non-Hispanics. Correlation with response to immunotherapy is ongoing. Continued research and focus on minority populations will further help to narrow known health disparities based on race and ethnicity.