1253P - Does gefitinib re-challenge or treatment beyond progression (TBP) prolong survival of NSCLC patients? - real world evidence from gefitinib treatment...

Date 29 September 2012
Event ESMO Congress 2012
Session Poster presentation I
Topics Anti-Cancer Agents & Biologic Therapy
Non-Small-Cell Lung Cancer, Metastatic
Presenter Yoshinobu Namba
Authors Y. Namba1, F. Imamura2, S. Morita3, M. Mori4, K. Komuta5, T. Kijima6, Y. Nakazawa4, S. Yokota4, S. Yamamoto5, A. Kumanogoh6
  • 1Respiratory Medicine, National Hospital Organization Toneyama National Hospital, 560-0045 - Toyonaka/JP
  • 2Department Of Thoracic Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka/JP
  • 3Biostatistics And Epidemiology, Yokohama City University Medical Center, Yokohama/JP
  • 4Department Of Thoracic Oncology, National Hospital Organization Toneyama National Hospital, Toyonaka/JP
  • 5Department Of Thoracic Oncology, Osaka Police Hospital, Osaka-city/JP
  • 6Department Of Thoracic Oncology, Osaka University Graduate School of Medicine, Suita/JP

Abstract

Background

After gefitinib was approved in July 2002, several patients have experienced long-term survival in the clinical setting. However, it is not yet clear which factor of treatment strategy is contributing to the long-term survival.

Methods

We extracted information from medical records of advanced NSCLC patients with the following inclusion criteria: 1) Japanese patients who were diagnosed by October 2010 and treated with gefitinib after July 2002. 2) Performance status (PS) 0-2. 3) PR, CR, or long SD (6 months or more) by gefitinib. 4) Patients who had not received curative surgical operation or radiation therapy. The primary objective was to evaluate the effects of treatment histories on Overall Survival (OS). We also conducted a “Dynamic Treatment Regimen Analysis (DTRA)” to identify the key treatment strategy contributing to long-term survival. DTRA included baseline clinical factors (sex, age, stage, histology, PS, smoking) and time-dependent clinical factors (PS, pretreatment).

Results

A total of 335 NSCLC patient details were extracted. The mean age was 64.8 years and 90.3% had adenocarcinoma histology. Sixty five patients experienced gefitinib re-challenge and 93 patients experienced gefitinib Treatment Beyond Progression (TBP). There was a statistical difference in OS between gefitinib re-challenge group and non re-challenge group (median OS was 1272 days vs 774 days; p < 0.001), Comparison of gefitinib TBP group and non TBP group also showed statistical difference (median OS was 1016 days vs 797 days; p = 0.035). Next, a cox regression model to investigate potential factors showed that “gefitinib re-challenge” was a factor which significantly contributed to long-term OS (HR: 0.515, 95%CI: 0.363-0.731; p = 0.0002) whereas “gefitinib TBP“ was not (HR: 0.787, 95%CI: 0.571-1.084; p = 0.1427). We confirmed this result using DTRA, The DTRA strongly supported the significant contribution of the gefitinib re-challenge treatment strategy to longer OS time.

Conclusion

This retrospective cohort that gefitinib re-administration may have a significant impact on OS in long surviving patients who experienced response to gefitinib.

Disclosure

All authors have declared no conflicts of interest.