Improved Efficacy of First-Line Imatinib in Advanced Gastrointestinal Stromal Tumors (GIST): The Dutch GIST Registry Data

Mahmoud Mohammadi; Nikki S IJzerman; Dide den Hollander; Roos F Bleckman; Astrid W Oosten; Ingrid M E Desar; An K L Reyners; Neeltje Steeghs; Hans Gelderblom

doi:10.1007/s11523-023-00960-y

Improved Efficacy of First-Line Imatinib in Advanced Gastrointestinal Stromal Tumors (GIST): The Dutch GIST Registry Data

Target Oncol. 2023 May;18(3):415-423. doi: 10.1007/s11523-023-00960-y. Epub 2023 Apr 20.

Authors

Mahmoud Mohammadi¹, Nikki S IJzerman^{2

3}, Dide den Hollander⁴, Roos F Bleckman⁵, Astrid W Oosten⁶, Ingrid M E Desar⁴, An K L Reyners⁵, Neeltje Steeghs², Hans Gelderblom⁷

Affiliations

¹ Department of Medical Oncology, Leiden University Medical Center, Leiden, 2300 RC, The Netherlands. m.mohammadi@lumc.nl.
² Department of Medical Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
³ Department of Medical Oncology, Erasmus MC Cancer Institute, Erasmus University Medical Center, Rotterdam, The Netherlands.
⁴ Department of Medical Oncology, Radboud University Medical Center, Nijmegen, The Netherlands.
⁵ Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
⁶ Department of Medical Oncology, Erasmus MC Cancer Institute, Rotterdam, The Netherlands.
⁷ Department of Medical Oncology, Leiden University Medical Center, Leiden, The Netherlands.

Abstract

Background: Patients with unresectable and metastasized gastrointestinal stromal tumor (GIST) experienced a remarkable improvement of progression-free survival (PFS) and overall survival (OS) after the introduction of imatinib. Our hypothesis is that the outcomes of treatment with imatinib are even better nowadays compared with the registration trials that were performed two decades ago. To study this, we used real-life data from a contemporary registry.

Methods: A multicenter, retrospective study was performed by exploring clinical data from a prospective real-life clinical database, the Dutch GIST Registry (DGR). Patients with advanced GIST treated with first-line imatinib were included and PFS (primary outcome) and OS (secondary outcome) were analyzed. Results of our study were compared with published results of the European Organisation for Research and Treatment of Cancer (EORTC) 62005 trial, which marked the first era of imatinib in the treatment of GIST.

Results: Overall, 420 of the 435 patients treated with imatinib in the DGR had recorded response evaluation and were included in the analysis. During a median follow-up of 35.0 months (range 2.0-136.0), progression of GIST was eventually observed in 217 patients (51.2%). The DGR cohort showed a longer median PFS (33.0 months, 95% confidence interval [CI] 28.4-37.6) compared with the EORTC 62005 trial (an estimated PFS of 19.5 months). Additionally, the median OS of 68.0 months (95% CI 56.1-80.0) was longer than the exposed median OS (46.8 months) published in the long-term follow-up results of the EORTC 62005 trial (median follow-up duration 10.9 years).

Conclusion: This study provides an update on outcomes of imatinib in the treatment of advanced GIST patients and demonstrates improved clinical outcomes since the first randomized studies of imatinib 2 decades ago. Furthermore, these results represent outcomes in real-world clinical practice and can serve as a reference when evaluating effectiveness of imatinib in patients with advanced GIST.

Publication types

Randomized Controlled Trial
Multicenter Study
Research Support, Non-U.S. Gov't

MeSH terms

Antineoplastic Agents* / adverse effects
Gastrointestinal Neoplasms* / drug therapy
Gastrointestinal Stromal Tumors* / drug therapy
Humans
Imatinib Mesylate / adverse effects
Prospective Studies
Retrospective Studies
Routinely Collected Health Data

Substances

Imatinib Mesylate
Antineoplastic Agents