Pathologic and Molecular Features Correlate With Long-Term Outcome After Adjuvant Therapy of Resected Primary GI Stromal Tumor: The ACOSOG Z9001 Trial

• DOI: 10.1200/jco.2013.51.2046
• Publication Date: 2014-03-18T05:41:02Z
• Authors: Christopher L. Co...; Karla V. Ballman; Cristina R. Anton...; Violetta Kolesnikova; Robert G. Maki; Peter W.T. Pisters; Martin E. Blackstein; Charles D. Blanke; George D. Demetri; Michael C. Heinrich; Margaret von Mehren; Shreyaskumar Patel; Martin D. McCarter; Kouros Owzar; Ronald P. DeMatteo
• Keywords: Adjuvant Therapy

Purpose The ACOSOG (American College of Surgeons Oncology Group) Z9001 (Alliance) study, a randomized, placebo-controlled trial, demonstrated that 1 year adjuvant imatinib prolonged recurrence-free survival (RFS) after resection primary GI stromal tumor (GIST). We sought to determine the pathologic and molecular factors associated with patient outcome. Patients Methods There were 328 patients assigned placebo arm 317 arm. Median follow-up was 74 months. 645 specimens available for mitotic rate or mutation analysis. Results RFS remained superior in (hazard ratio, 0.6; 95% CI, 0.43 0.75; Cox model–adjusted P < .001). On multivariable analysis arm, large size, small bowel location, high lower RFS, whereas genotype not significantly RFS. Multivariable yielded similar findings. When comparing two arms, therapy higher KIT exon 11 deletion any type, but insertion point mutation, 9 PDGFRA wild-type tumor, although some these groups small. Adjuvant did seem alter overall survival. Conclusion Our findings show rate, genotype, are natural history GIST. deletions had longer