Prognostic analysis of gastrointestinal stromal tumor by mitotia activity, size of tumor and mutational type of c-kit protein

초록

GIST is the most common mesenchymal tumor of the gastrointestinal tract. Methods: 53 GIST patients, underwent grossly total mass resection in Inha University Hospital, Incheon, Korea from March 1997 to March 2004, were included in this study. The median follow-up period was 34 months. The evaluation of C-kit mutation on exon 11 was performed . Results: The median value of mass size was 6 Cm(range, 0.8Cm - 20Cm). The most common primary site was stomach with 30 cases(56%), followed by small bowel with 11 cases, large bowel with 6 cases and peritoneal dissemination with 6 cases. The rates of 3-year recurrence free survival and 3-year overall survival were 50% and 76%, respectively. Three-year recurrence free survival rate of patients with less then 10 mitotic activity under 50 HPF was 79%, whereas the rate of patients with more than 10 mitotic activity under 50 HPF was 30%(p=0.026). Three-year overall survival rates of patients with less than 10 mitotic activity and that of patients with more than 10 mitotic activity were 90% and 64%, respectively(p=0.0368). Three-year recurrence free survival rate of patients with tumor size less than 5 Cm was 77% and the rate of patients with tumor size greater than 5 Cm was 33%(p=0.0006). The 3-year overall survival rates of patients with tumor size less than 5Cm and that of patients of tumor size greater than 5Cm were 86% and 66%, respectively(p=0.023). The study on mutational type of C-kit protein showed missence exon 11 mutation with 4 cases(7%) and deletion/insertion exon 11 mutation with 24 cases(45%). Three-year recurrence free survival rate of deletion/insertion exon 11 found to be 35% as the rate of rest patients was 64% and the difference between these two groups showed statistical significance.(p=0.0383). Conclusions: This study showed that mass size and mitotic activity were important prognostic factors in GIST. Delete/Insert gene mutation on exon 11 was found to be poor prognostic factor.