Author of

• 32374

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  P2.13 - Staging (ID 315)

  • Event: WCLC 2019
  • Type: Poster Viewing in the Exhibit Hall
  • Track: Staging
  • Presentations: 1
  • Moderators:
  • Coordinates: 9/09/2019, 10:15 - 18:15, Exhibit Hall

  • 32382

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    P2.13-06 - Finding a Place for Pathological Near Complete Response Patients Following Neoadjuvant/Induction Therapy in the TNM Staging (ID 1029)

    10:15 - 18:15  |  Author(s): Erhan Özer
    • Abstract

    Background
    

    It has been shown that 10% or less in the number of live tumor cells in patients who underwent surgery after neoadjuvant/induction (N/I) treatment for locally advanced non-small cell lung cancer (NSCLC) is a more important prognostic factor than the tumor diameter. Therefore, to improve the accuracy of TNM staging, the IASLC recommends calculating the new pathological ypT stage by multiplying the percentage of viable tumor cells with the total tumor size (Picture 1). The aim of this study was to determine the effect of this recommendation on long-term survival rates.

    Method
    

    Data of 1190 patients who underwent segmentectomy or larger lung resections for NSCLC in our academic center between 1996 and 2017 were prospectively recorded and evaluated retrospectively. Four hundred and sixty-nine (39.4%) patients who underwent surgery after N/I treatment for locally advanced NSCLC were included in the study. The patients were divided into 3 groups; Pathological complete response (CR, Group 1) as defined as no viable tumor cells regardless of tumor size, group 2 was accepted as near complete response (nCR), where the tumor contained ≤%10 live tumor cells, tumor size > 5 cm without lymph node metastasis, group 3 consisted of ypStage1 patients. The long term survival and its impacting factors were analyzed.

    Result
    

    In histopathological examination, 16.6% (78/469) patients had CR, 4% (19/469) had nCR, 17.7% (83/469) had ypStage 1a and 7.7% (36/469) had ypStage 1b. Five-year survival; 72.5% in Group 1, 30% in Group 2 and 63.4% in Group 3.

    Conclusion
    

    The best survival was observed in patients with pathological CR. Although, IASLC suggests that the nCR should be considered as Stage 1, because of the significantly low survival figures, T3-4 seems to be the more appropriate classification than the IASLC proposal.

    

    Picture 1. A 48y male patient with 12-cm mass adjacent to the trachea (1a). Diagnosis of NSCLC was confirmed. Major response was observed after chemoradiotherapy (1b). After negative mediastinoscopy, right upper lobectomy and lower lobe superior segmentectomy was performed with a bronchoplasty. Histopathological examination revealed a tumor size of 7.5x6 cm with live tumor cells ≤5% without lymph node metastasis. The IASLC recommends (T stage = Tumor Size x Number of Live Tumor Cells (5%)) patient's stage as ypStage 1.