Zifeng Yang. Guangdong General Hospital
Introduction: The primary small gGIST should be treated as benign tumor without high-risk EUS features. But the size of the small GIST of the community continues to be controversial, 1cm or 2cm, is not yet a consensus on the formation of the problem.
Methods: Retrospective collecte clinical pathology data and prognosis information from 1998. 01-2015. 12 in four medical centers of southern China . Tumor size was divided into <1cm and 1-2cm two groups.
Results: 4 medical centers in 18 years were treated 276 cases of primary small gGIST. The median follow-up time was 38 months (3-156 months). 2 cases of recurrence, 2 cases of death. The overall 5-year survival rate was 98.7%. The tumor size is 0.2-2.0cm. The median size is 1.0cm.Using the Pearson line correlation analysis, there was a positive correlation between the mitotic count and the tumor size as continuity variable (r = 0.164, p = 0.006). The whole group was divided into two groups: <1cm gGIST (Micro group) and 1-2cm gGIST (Small group). There were 137 cases of Micro group and 139 cases of Small group. There was no significant difference between the two groups in age, sex, diagnosis, tumor location, adjuvant therapy, relapse, surgical procedure, resection, complication, positive margin, immunohistochemical expression (P> 0.05). In mitotic count, Micro group :≤ 5 / 50HPF 134 cases,> 5 / 50HPF ≤ 10 / 50HPF 0 cases,> 10 / 50HPF 3 cases, meanwhile Small group:≤ 5 / 50HPF 125 cases,> 5 / 50HPF ≤ 10 / 50HPF 7 cases,> 10 / 50HPF 7 cases, there was a statistically significant difference between this two groups (p = 0.002). Small group had more intermediate/high risk cases, so there was also a statistically significant difference between the two groups (p = 0.002). Using the receiver operating characteristic curve (AUC = 0.707. P = 0.004) and the Gordon index, we found that 1.15cm was the best cutoff to separate low-risk cases and intermediate/high risk cases (sensitivity = 0.824, 1-specificity = 0.429).
Conclusions: Primary small gGIST has a good prognosis.For <1cm gGIST (Micro group), it can be regarded as benign, just need the EUS follow-up. For 1-2cm gGIST (Small group), the proportion of intermediate/high-risk cases is high, we think it needs to be treated with caution, resect it if necessary. 1.15cm may be the new cut-off threshold to separate the small gGIST and large gGIST, but it still needs more cases to verify.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 86487
Program Number: P397
Presentation Session: iPoster Session (Non CME)
Presentation Type: Poster