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Soon Ho Yoon



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    OA 14 - New Paradigms in Clinical Trials (ID 681)

    • Event: WCLC 2017
    • Type: Oral
    • Track: Clinical Design, Statistics and Clinical Trials
    • Presentations: 1
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      OA 14.01 - The Impact of Measurement Variability on Response Categorization in Oncology Trials (ID 9986)

      11:00 - 12:30  |  Presenting Author(s): Soon Ho Yoon

      • Abstract
      • Presentation
      • Slides

      Background:
      Radiologic assessments of the baseline and post-treatment tumor burden are subject to measurement variability, but the impact of this variability on response categorization and the resulting overall response rate (ORR) in a specific trial has been practically unpredictable.

      Method:
      We built up a hierarchical model of measurement variability using a clinical trial dataset of CT scans. Simulations were then performed using the model 1) to establish the behaviour of differences between the first and the hypothetical second assessments of percent change of tumor burden in various scenarios, 2) to elaborate on the probabilistic nature of decisions about categorization, and 3) to estimate the variation in the ORR due to measurement variability.

      Result:
      The extent of the discrepancies between assessments of the percent change depended on the baseline burden. Smaller differences were associated with larger shrinkage of tumor burdens. The simulated probability for a specific categorization (-30% or 20%) to result from reassessment had a sigmoid shape depending on the percent change in the first set of readings, inflecting at the cutoff point for the categorization. In 3 virtual trials having the same baseline burden and the same ORR of 50%, the presence of fewer percent changes around the cutoff in a trial resulted in a more reproducible ORR (95% central range, 35%-65% vs. 40%-60% vs. 45%-60%). Figure 1



      Conclusion:
      Since determinations of partial response or progression are probabilistic outcomes due to measurement variability, quantification of the variation in the ORR by potential measurement variability is essential and will help inform decisions made on the basis of trial data.

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    P1.13 - Radiology/Staging/Screening (ID 699)

    • Event: WCLC 2017
    • Type: Poster Session with Presenters Present
    • Track: Radiology/Staging/Screening
    • Presentations: 1
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      P1.13-011d - Risk of Pleural Recurrence After Percutaneous Transthoracic Needle Biopsy in Stage I Non-Small Cell Lung Cancer: A Large Center Experience (ID 10019)

      09:30 - 16:00  |  Author(s): Soon Ho Yoon

      • Abstract
      • Slides

      Background:
      To determine whether percutaneous transthoracic needle biopsy (PTNB) increase the risk of (a) isolated pleural recurrence and (b) concomitant pleural seeding and metastasis in stage I non-small cell lung cancer (NSCLC).

      Method:
      In this institutional review board-approved retrospective study, medical records of total of 830 consecutive patients with stage I NSCLC who underwent curative resection between 2004 and 2010 were reviewed. Median duration of follow-up was 1843 days (interquartile range, 1006-2734). Multiple logistic regression analyses were performed to identify risk factors of pleural recurrence.

      Result:
      Of 830 patients, 540 patients (65.1%) underwent PTNB before surgery, while 290 patients (34.9%) underwent non-PTNB procedures including bronchoscopic biopsy or exploratory thoracotomy. An isolated pleural recurrence was found in 26 patients (3.1%, [95%CI, 2.1-4.6%]) (20 in PTNB group, 6 in non-PTNB group). There was no significant association between PTNB and isolated pleural recurrence (P=0.197). Concomitant pleural recurrence occurred in 42 patients (5.1%, [95%CI, 3.8-6.8%]) (34 in PTNB group, and 8 in non-PTNB group). Subpleural location (p=0.007), tumor consistency (solid, part-solid, nonsolid) (p=0.046), PTNB (p=0.027), pathologic T stage (p<0.001), microscopic pleural invasion (p<0.001) and microscopic lymphatic invasion (p=0.019) were associated with concomitant pleural recurrence. The most significant factor of pleural recurrence was only microscopic pleural invasion (Odds Ratio, 4.28; 95% CI, 2.20 to 8.29) (P<0.001) on multiple logistic analysis. Among 540 patients undergoing PTNB, transfissural approach did not have significant association with pleural recurrence (P=0.220), while the most sole significant factor was microscopic pleural invasion (Odds Ratio, 3.40; 95% CI, 1.54 to 7.51) (P=0.002).

      Conclusion:
      PTNB did not increase the risk of isolated or concomitant pleural recurrence in early stage NSCLC. Higher incidence of concomitant pleural seeding in PTNB group was presumably attributed to peripheral lung cancer, potentially accompanying microscopic pleural invasion.

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