Gastrointestinal stromal tumours (GISTs) are the commonest mesenchymal tumours in the gastrointestinal tract. A paradigm of molecularly targeted therapy in GISTs made imatiniban effective therapy. This study aims to analyse treatment outcomes of GIST patients treated with imatinib in Sarawak General Hospital (SGH) and todetermine prognostic factors associated with survivals.
Fifty patients diagnosed with GIST for treatment with imatinib were included in this retrospective study. Patient data were retrieved from clinic records, pharmacy census and GIST patient database.
In our cohort, male predominance was observed (60%) with mean age of 57.7 years old. The commonest primary site is stomach (48%) followed by small bowel (24%).70% patients are diagnosed as advanced GIST, metastasis seen primarily in the liver (68.6%). Imatinib dose adjustment was required in 14 (28%) patients, 64.3% due to disease progression and 35.7% due to toxicity. Anaemia (36%) is the commonest reported side effect followed by skin toxicity (20%) and neutropenia (16%). The median survivalfor patients was 301.21 days using Kaplan Meier analysis whereas median progression free survival was 105 days. Log Rank test for survival of different treatment post progression showed significant difference in survival between imatinib dose escalation versus best supportive care(X2 statistics: 4.263; p = 0.039).However, no significant difference wasseen between imatinib dose escalations versus second line Sunitinib(X2 statistics: 1.471; p = 0.225). The table illustrates prognostic factors associated with survival using Simple Cox Regression.Table: 116P
|Variables||HR (95% CI)||P value|
|Age||0.964 (0.903, 1.029)||0.271|
|Gender Female Male||1.00 1.183 (0.290, 4.827)||0.814|
|ECOG||4.071 (0.725, 22.879)||0.111|
|Size 5-10CM >10CM||1.00 0.408 (0.084, 1.987)||0.267|
|Distant Metastasis No Yes||1.00 2.327(0.272,19.889)||0.440|
|Mitotic Index (MI/50hpf) <5 >10||1.00 2.035 (0.364, 11.390)||0.419|
From our study, we conclude that poor ECOG, high mitotic index and advanced GIST carry higher risk to death numerically. Imatinib dose escalation upon progression has significantly better survival compared to best supportive care.
Clinical trial identification
NMRR ID 40174.
Legal entity responsible for the study
Has not received any funding.
All authors have declared no conflicts of interest.