Published in:
01-04-2016 | Original Article
Prognostic factors after imatinib secondary resistance: survival analysis in patients with unresectable and metastatic gastrointestinal stromal tumors
Authors:
Tatsuo Kanda, Takashi Ishikawa, Shin-ichi Kosugi, Kyo Ueki, Tetsuya Naito, Toshifumi Wakai, Seiichi Hirota
Published in:
International Journal of Clinical Oncology
|
Issue 2/2016
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Abstract
Background
Patients undergoing imatinib therapy for gastrointestinal stromal tumors (GISTs) show drug resistance during treatment in the late stages. The aims of this study were to determine survival after the appearance of imatinib secondary resistance (ISR) and to identify the prognostic factors.
Methods
Eligible were patients with unresectable and metastatic GISTs who were diagnosed with ISR and/or underwent treatment for ISR in our institution between 2001 and 2012. A total of 48 patients were enrolled and overall survival was retrospectively analyzed. The Cox proportional hazards model was used to identify the independent prognostic factors. Median follow-up time was 58 months.
Results
As of the cutoff date, 41 of the 48 patients with ISR had died, of which 39 died of GISTs. The overall 1-, 3-, and 5-year survival rates of the 48 patients were 64.6, 32.8, and 20.4 %, respectively, and median survival time was 22 months. The favorable independent prognostic factors identified were long progression-free survival in first-line imatinib therapy (P = 0.04), small diameter of progressive disease (PD) (P = 0.02), and surgical resection of PD (P = 0.01).
Conclusion
Surgical resection of PD in selected cases could improve prognosis in ISR patients undergoing GIST treatment.