Author of

• 25929

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  P1.09 - Pathology (Not CME Accredited Session) (ID 941)

  • Event: WCLC 2018
  • Type: Poster Viewing in the Exhibit Hall
  • Track:
  • Presentations: 1
  • Moderators:
  • Coordinates: 9/24/2018, 16:45 - 18:00, Exhibit Hall

  • 26535

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    P1.09-33 - Validity of Non-Small Cell Lung Cancer Not Otherwise Specified to Use Immunohistochemistry on Treatment Outcome (ID 11190)

    16:45 - 18:00  |  Presenting Author(s): Takahiro Ota
    • Abstract

    Background
    

    In non-small cell lung cancer, histologic samples have become significantly important to administrate tumor type specific cytotoxic and molecular-targeted therapies. When a biopsy sample shows lacking definite morphology, diagnosis is made into three subtypes, favour adenocarcinoma, favour squamous cell carcinoma and NOS-null, according to the immunohistochemistry (IHC) results. However, in terms of the patient outcome, validity of IHC-based these classification have been unknown yet.

    a9ded1e5ce5d75814730bb4caaf49419 Method
    

    A series of 152 advanced NSCLC patients whose diagnosis was made by morphology and homogeneously treated was enrolled. We performed IHC staining (TTF-1, SP-A, p40, and CK5/6) of these samples and refined diagnoses into 3 subtypes. We analyzed the pathological subgroup depends on IHC staining with clinical characteristics including molecular analysis, response of chemotherapy and prognosis.

    4c3880bb027f159e801041b1021e88e8 Result
    

    IHC profiling displayed that 50% of cases was favour Ad, 31% was favour SqCC, and 19% was NOS-null. On the patient background, there was no difference in age, smoking history, and PS, but there were differences in gender, and the favour Ad group had more females than other groups. EGFR mutation was significantly more expressed in favour Ad group than in the other groups, and molecular targeted drugs in initial treatment were used in favour Ad group in a large proportion. Compared with favour Ad and SqCC group, NOS-null group showed significantly poorer outcome in terms of median overall survival (OS). Between favour Ad and favour SqCC group, median OS was better in favour Ad group (19.5 months vs 15.0 months, p = 0.018). Excluding patients using molecular targeted drugs, there was no difference in median OS between favour Ad and favour SqCC group (15.2 months vs 15.0 months p = 0.29). Pemetrexed containing platinum regimen showed similar response rate as other platinum regimen in the favour Ad cohort (43% vs 46%), whereas poorer response in the favour SqCC (0% vs 50%) and NOS-null (0% vs 24%) cohort. Although patients to be received pemetrexed containing platinum regimen compared to those to be received other platinum regimen demonstrated a trend toward good PFS in favour Ad group, there were no statistically differences.

    8eea62084ca7e541d918e823422bd82e Conclusion
    

    This study made clear chemo-responsiveness, the expression frequency of driver mutation and prognosis in NSCLC favour Ad, SqCC and NOS-null. These findings support that histological subtyping in biopsy specimen by IHC would be mandatory to archive appropriate therapy.

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