TY - JOUR
T1 - Effectiveness of adjuvant imatinib in patients with gastrointestinal stromal tumor
T2 - Results of a population-based, matched-cohort study
AU - Hatoum, Hind T.
AU - Lin, Swu Jane
AU - Sasane, Medha
AU - Trent, Jonathan C.
PY - 2012/5/1
Y1 - 2012/5/1
N2 - Objective: Data are limited on the use of adjuvant imatinib in patients with gastrointestinal stromal tumor (GIST) outside of clinical trials. This retrospective, population-based, matched-cohort study evaluated adjuvant imatinib treatment patterns, assessed impact on clinical outcomes, and estimated effectiveness based on number needed to treat (NNT). Research design and methods: GIST-related claims from the PharMetrics claims database were included (20002010). A stepwise identification algorithm identified appropriate patients based on GIST-related ICD-9-CM codes, who were classified as 'imatinib (IM) patients' receiving imatinib within 84 days post-surgery and 'non-imatinib (non-IM) patients' undergoing surgery but not receiving imatinib during the study period. The primary composite outcome was based on incidence of a second GIST-related surgery and long-term follow-up in the matched cohorts. IM patients were matched with up to eight non-IM patients on age, gender, ICD-9-CM code, and first surgery date. Results: A total of 118 IM and 4088 non-IM patients with possible GIST ICD-9s and surgery were included. The median duration between first and second surgeries was significantly longer in IM than non-IM patients (488vs. 290 days; p0.0005). IM patients also had longer median follow-up from initial surgery to composite outcome (433vs. 320 days; p0.002). Adherence to IM, measured by medication possession ratio, was 0.83 and 0.73 during the first and second years of treatment, respectively. IM patients were less likely to have the composite outcome compared with non-IM patients (hazard ratio0.501; p0.0005). The NNT to prevent one outcome was 4. Conclusions: Patients receiving adjuvant imatinib treatment were less likely to have second surgery or be lost to follow-up, and had a longer interval to second surgery. Although treatment with adjuvant imatinib in patients with primary GIST is effective, adherence to imatinib and treatment duration are less than recommended by current treatment guidelines.
AB - Objective: Data are limited on the use of adjuvant imatinib in patients with gastrointestinal stromal tumor (GIST) outside of clinical trials. This retrospective, population-based, matched-cohort study evaluated adjuvant imatinib treatment patterns, assessed impact on clinical outcomes, and estimated effectiveness based on number needed to treat (NNT). Research design and methods: GIST-related claims from the PharMetrics claims database were included (20002010). A stepwise identification algorithm identified appropriate patients based on GIST-related ICD-9-CM codes, who were classified as 'imatinib (IM) patients' receiving imatinib within 84 days post-surgery and 'non-imatinib (non-IM) patients' undergoing surgery but not receiving imatinib during the study period. The primary composite outcome was based on incidence of a second GIST-related surgery and long-term follow-up in the matched cohorts. IM patients were matched with up to eight non-IM patients on age, gender, ICD-9-CM code, and first surgery date. Results: A total of 118 IM and 4088 non-IM patients with possible GIST ICD-9s and surgery were included. The median duration between first and second surgeries was significantly longer in IM than non-IM patients (488vs. 290 days; p0.0005). IM patients also had longer median follow-up from initial surgery to composite outcome (433vs. 320 days; p0.002). Adherence to IM, measured by medication possession ratio, was 0.83 and 0.73 during the first and second years of treatment, respectively. IM patients were less likely to have the composite outcome compared with non-IM patients (hazard ratio0.501; p0.0005). The NNT to prevent one outcome was 4. Conclusions: Patients receiving adjuvant imatinib treatment were less likely to have second surgery or be lost to follow-up, and had a longer interval to second surgery. Although treatment with adjuvant imatinib in patients with primary GIST is effective, adherence to imatinib and treatment duration are less than recommended by current treatment guidelines.
KW - Adjuvant drug therapy
KW - Gastrointestinal stromal tumors
KW - Imatinib
KW - Outcomes assessment
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U2 - 10.1185/03007995.2012.685928
DO - 10.1185/03007995.2012.685928
M3 - Article
C2 - 22506625
AN - SCOPUS:84861131012
VL - 28
SP - 805
EP - 814
JO - Current Medical Research and Opinion
JF - Current Medical Research and Opinion
SN - 0300-7995
IS - 5
ER -