271P - Target therapy treatment patterns on advanced gastrointestinal stromal tumor (GIST) patients: a nation-wide cohort study in Taiwan

Date 17 December 2016
Event ESMO Asia 2016 Congress
Session Poster lunch
Topics Anticancer agents
GIST
Personalised/Precision Medicine
Presenter I-Jen Chiang
Citation Annals of Oncology (2016) 27 (suppl_9): ix68-ix85. 10.1093/annonc/mdw582
Authors I. Chiang1, C. Yang2, Y. Chen3, W. Fang4
  • 1Graduate Institute Of Data Science, Taipei Medical Unversity, 110 - Taipei/TW
  • 2Department Of Surgery, National Taiwan University Hospital, 100 - Taipei/TW
  • 3Department Of Internal Medicine, Chang Gung Memorial Hospital-Kaohsiung, 83301 - Kaohsiung/TW
  • 4Taiwan Division, Pfizer Limited, 25159 - Taipei/TW

Abstract

Background

Imatinib and sunitinib are two reimbursed targeted therapies for advanced GIST in Taiwan. A national-wide study was performed to evaluate the targeted therapies in GIST treatment among Taiwanese population.

Methods

We conducted a nationwide retrospective cohort study based on data from the National Health Insurance Research Database (NHIRD) between January 2005 and December 2010. All 1186 patients enrolled had histology-confirmed GIST with first-line imatinib (400mg qd) and follow-up more than one year. We estimated recurrence-free survival (RFS), progression-free survival (PFS), and overall survival (OS) probabilities with the Kaplan-Meier method. The proportional hazards assumption was verified by tests of correlations with time and examination of residual plots, and only variables that were deemed statistically significant were included in the final Cox model.

Results

With a median follow-up for surviving patients of 42 months, the median PFS of the cohort was 31 months since first-line imatinib. Cox proportional hazards multivariate analysis demonstrated directly switching to sunitnib was significant (hazard ratio: 0.77; 95% CI: 0.55-1.08; p 

Conclusions

Taiwanese advanced GIST patients who failed first-line treatment still gained benefit from either imatinib dose escalation or a switch to sunitinib. Significant improvement in PFS using sunitnib directly as switch maintenance in advanced GIST.

Clinical trial indentification

In 1995, Taiwan launched a single-payer National Health Insurance program, and as of 2007, 22.60 million of Taiwan's 22.96 million population were enrolled in this program. Each year, the Bureau of National Health Insurance, Taiwan, collects data, including registration files and original claim data for reimbursement, from the National Health Insurance, and sorts it into data files. These data files are de-identified by scrambling the identification codes of patients, medical institutions and physicians and sent to the National Health Research Institutes, Taiwan, to form the original files of the NHIRD. Therefore, these files contain all the records of individuals enrolled in the National Health Insurance program, and they are available for research purposes only.

Legal entity responsible for the study

Taipei Medical University

Funding

Pfizer Limited, Taiwan Division

Disclosure

All authors have declared no conflicts of interest.