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Rathi Pillai



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    P1 - Poster Viewing (ID 5)

    • Event: NACLC 2019
    • Type: Poster Session
    • Track:
    • Presentations: 1
    • Moderators:
    • Coordinates: 10/11/2019, 16:45 - 18:00, Exhibit Hall
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      P1.15 - The Presence of Secondary Follicles in Early Stage Lung Adenocarcinoma Reflects Disease Burden. (ID 120)

      16:45 - 18:00  |  Author(s): Rathi Pillai

      • Abstract

      Background:
      Immunotherapy with checkpoint blockade has become standard treatment modality for lung cancer. A subset of patients treated with checkpoint blockade therapy have durable responses but identification of which patients respond to therapy is difficult. A combination of biomarkers (e.g. PD-L1 immunostaining), tumor mutation burden, and tumor immune microenvironment are contributing factors. To better understand whether specific components of the immune microenvironment affect the biology of lung cancer, we studied B cell-related processes which can be associated with either activated or regulatory T cells. Secondary lymphoid follicles, in which mature B cells proliferate and differentiate in response to exposure to antigen, form as part of an immune response with germinal center formation. The presence of these structures is an indication of an ongoing, possibly productive immune response. However, the significance and importance of these organized lymphoid structures within tumors is less well-understood. In this study, we evaluated the presence of secondary lymphoid follicles and correlated them with clinicopathologic features of lung adenocarcinoma.


      Method:
      Formalin-fixed paraffin-embedded tissues from 70 cases of early stage (Stages I-II) lung adenocarcinoma were evaluated for the presence of lymphoid aggregates, secondary follicles, and lymphocytic infiltrate. CD20, CD3, BCL-6, and BCL-2 expression in the tumors were evaluated by immunohistochemistry. The presence of secondary follicles was confirmed by morphology and BCL-6 expression within follicles. Statistical analyses were formed to determine the correlations between secondary follicles, tumor grade, stage, and overall survival.


      Results:
      The average tumor size was larger in lung adenocarcinomas with secondary follicles. The presence of secondary follicles in tumors correlated with disease stage (p=0.01) and not tumor grade (p=0.1) or the density of B cell infiltrates (p=0.25). Patients with secondary follicles had worse overall survival than patients without secondary follicles (p=0.03). Overall survival was also significantly worse for patients with high-grade tumors (Grade 3; p=0.0001) and Stage II disease (p=0.002). Interestingly, overall survival was significantly worse in Stage I patients with secondary follicles in tumors compared to those without secondary follicles (p=0.03) and the average tumor size in Stage I patients with secondary follicles was larger.


      Conclusion:
      The presence of secondary follicles in lung adenocarcinoma likely reflects disease burden and thus, is associated with worse survival. These results suggest that further characterization of secondary lymphoid follicles and disease burden is needed. A better determination of the role of secondary follicles in the immunosurveillance of lung cancer may elucidate the role of the tumor immune microenvironment in lung cancer pathogenesis and immunotherapeutic intervention.