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David Catharina Petrus Cobben



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    P1.04 - Immuno-oncology (ID 164)

    • Event: WCLC 2019
    • Type: Poster Viewing in the Exhibit Hall
    • Track: Immuno-oncology
    • Presentations: 1
    • Now Available
    • Moderators:
    • Coordinates: 9/08/2019, 09:45 - 18:00, Exhibit Hall
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      P1.04-44 - Radiomics for Predicting Response to First-Line Anti-PD1 Therapy in Advanced NSCLC (Now Available) (ID 2172)

      09:45 - 18:00  |  Author(s): David Catharina Petrus Cobben

      • Abstract
      • Slides

      Background

      Radiomics is the high-throughput extraction of quantitative imaging features from medical images that can reflect underlying tumour pathophysiology. Imaging biomarkers have the potential to improve disease characterisation and predict patient outcomes. In this study, the utility of radiomic features to predict response and survival to first-line immune check-point inhibition with pembrolizumab in advanced non-small cell lung cancer (NSCLC) was explored.

      Method

      Patients with Stage IIIB/IV NSCLC treated with first-line pembrolizumab and PD-L1 ≥50% were retrospectively identified and stratified by Best Overall Response (BOR) by RECIST 1.1. Patients with the primary tumour in situ and a contrast-enhanced CT thorax/abdomen (minimum 5mm CT slice thickness) at baseline were included. The single largest thoracic lesion was segmented in the diagnostic image using the Pinnacle radiotherapy treatment planning system. All tumour delineations were supervised by a highly experienced certified senior radiologist. Lesions <1cm, inflammatory and indeterminate lesions were excluded from delineation. A total of 47 radiomic features including shape, first-order and texture features were extracted from the segmented tumour using PyRadiomics. No pre-processing of the images was performed. Highly correlated features (r>0.85) were removed from further analysis. Least Absolute Shrinkage and Selection Operator (LASSO) feature selection was performed to find informative features that could predict either best overall response or overall survival. Univariate logistic regression and cox proportional hazard models were then used for an initial assessment of the potential of these features in predicting response and survival respectively.

      Result

      Sixteen patients with evaluable best overall response (partial response n=9, progressive disease n=7) were selected for the initial discovery-cohort. Mean age was 68 years with 63% adenocarcinoma histology. From the 47 features extracted, 32 were highly correlated to each other and were removed from further analysis. For predicting best overall response, LASSO selected 5 features with univariate logistic regression suggesting that tumour surface area to volume ratio might be informative (p=0.057, AUC of 0.83 (95% CI 0.61-1.0)). With respect to overall survival, LASSO selected 3 features with univariate cox regression suggesting the first-order feature skewness might be predictive (HR = 0.27, 95% CI 0.08-0.88, p=0.03). When split on the median skewness value the Kaplan-Meier plot showed a significant survival difference between high and low risk patients (p=0.007).

      Conclusion

      Radiomic features extracted from baseline contrast-enhanced CT scans may have the potential to predict response and survival in patients treated with first-line pembrolizumab in advanced NSCLC. We emphasize the exploratory nature of these results given the very limited number of patients in the study. We are expanding this discovery cohort to further investigate and validate these results. Updated results will be presented at the meeting.

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    P2.08 - Oligometastatic NSCLC (ID 172)

    • Event: WCLC 2019
    • Type: Poster Viewing in the Exhibit Hall
    • Track: Oligometastatic NSCLC
    • Presentations: 1
    • Moderators:
    • Coordinates: 9/09/2019, 10:15 - 18:15, Exhibit Hall
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      P2.08-02 - Outcomes Following Stereotactic Radiosurgery for Syncronous Brain Metastases in Non-Small Cell Lung Cancer (ID 426)

      10:15 - 18:15  |  Author(s): David Catharina Petrus Cobben

      • Abstract
      • Slides

      Background

      Approximately 10% of non-small cell lung cancer (NSCLC) patients have brain metastases at presentation. The use of stereotactic radiosurgery (SRS) has enabled a proportion of patients with oligometastatic brain disease to be offered a radical treatment in conjunction with SRS. We evaluated the outcomes for patients presenting with synchronous brain metastases who received SRS to determine if radical treatment improves survival.

      Method

      164 patients with NSCLC received SRS for brain metastases between January 2012 and December 2017. This analysis focused on 71 patients who presented synchronously with brain metastases. Electronic patient records were accessed in March 2019 to determine initial extracranial disease treatment and date of death or last follow up.

      Result

      30 patients received radical treatment (18 radiotherapy alone, 11 chemo-radiotherapy and one surgery) and 24 received palliative treatment (17 chemotherapy, four radiotherapy and three tyrosine kinase inhibitor). 17 patients received no treatment following SRS, either due to death, deterioration in performance status or patient choice. Baseline demographics are presented in table 1.

      table 1.jpg

      Median overall survival for the radical, palliative and no treatment groups were; 7.9 (95% CI 5.5-14.0), 9.4 (6.6-14.4) and 1.4 (1.0-2.9) months, respectively. There was no significant difference in survival between the radical and palliative groups (p=0.43). Kaplan-Meier survival estimates at 12 and 24 months were 30.0% (95% CI 17.4- 51.8%) and 10.0% (3.4-29.3%) for the radical and 33.3% (18.9- 58.7%) and 13.0% (4.1-41.4%) in the palliative group, respectively.

      Conclusion

      Our results did not demonstrate the benefit for radical treatment, as expected based on published data. Potential reasons for this result include a lack of tools to select patients for radical treatment. Prospective studies are needed to identify the optimal treatment for extracranial disease in this patient group.

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    P2.17 - Treatment of Early Stage/Localized Disease (ID 189)

    • Event: WCLC 2019
    • Type: Poster Viewing in the Exhibit Hall
    • Track: Treatment of Early Stage/Localized Disease
    • Presentations: 1
    • Moderators:
    • Coordinates: 9/09/2019, 10:15 - 18:15, Exhibit Hall
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      P2.17-02 - Survival in Performance Status 3 Non-Small Cell Lung Cancer Patients Receiving Radical Radiotherapy (ID 291)

      10:15 - 18:15  |  Author(s): David Catharina Petrus Cobben

      • Abstract
      • Slides

      Background

      International guidelines currently recommend radical radiotherapy for non-small cell lung cancer (NSCLC) patients with ECOG performance status (PS)0-2. Despite a paucity of evidence for treating poorer PS patients, modern advances have allowed patients with PS3 to be offered radical radiotherapy.

      Method

      PS0-3 NSCLC patients receiving radical radiotherapy at The Christie Hospital, UK between August 2016-October 2017 were retrospectively identified from hospital electronic patient records. Survival was calculated from date of first oncology review to November 2018. Baseline and treatment characteristics for PS3 patients were recorded including adult comorbidity evaluation (ACE)-27 score, pulmonary function, radiation dose volume parameters and radiotherapy regimen (i.e stereotactic ablative radiotherapy (SABR) vs standard radiotherapy (50-55Gy/20 fractions)).

      Result

      504 patients were identified: 440(87%) PS0-2 and 64(13%) PS3. Six PS3 patients withdrew themselves; four before treatment and two after one fraction. Of 58/64(91%) PS3 patients completing radiotherapy, 43(74%), 4(7%), 10(17%) and 1(2%) were Stage I, II, III and IV at diagnosis, respectively. ACE-27 score was 0, 1, 2 and 3 in 3(5%), 8(14%), 16(28%) and 31(53%) patients, respectively. 31(53%) received SABR and 27(47%) standard radiotherapy. On intention-to-treat analysis, there was no significant difference in survival over 18 months in PS3 patients compared to PS0-2; p=0.858 (Fig.1). There was no significant difference in survival among PS3 patients completing radiotherapy when stratifying by stage(I vs II vs III) (p=0.343), ACE-27 score(1 vs 2 vs 3)(p=0.266), or radiotherapy regimen(p=0.655). Lung function tests(FEV1, FVC) and radiotherapy dose volume parameters(PTV, V5, V10,V20) failed to predict survival of PS3 patients at 6, 12 and 18 months.

      nsclc rb.png

      Conclusion

      This study demonstrates that PS3 patients receiving radical radiotherapy had a similar 18-month survival compared to PS0-2 patients and baseline and treatment characteristics did not predict overall survival in PS3 patients. This suggests more PS3 patients could be considered for radical radiotherapy and further studies with larger cohorts are recommended.

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