Introduction:Gastric gastrointestinal tumors (GIST) are a rare and usually asymptomatic neoplasm that can present as abdominal mass in more advanced scenarios. Since surgical resection is the main aspect of the treatment, locally advanced tumors require multivisceral resection and, therefore, higher postoperative morbidity and mortality. Objective:To perform a review the literature on the topic, with emphasis on the neoadjuvant therapy. Methods:Literature review on the Medline database using the following descriptors: gastrointestinal stromal tumors, neoadjuvant therapy, imatinib mesylate and molecular targeted therapy. Results:Surgical resection remains the cornerstone for the treatment of GISTs; however, tyrosine kinase inhibitors have improved survival as an adjuvant therapy. More recently, neoadjuvant therapy have been described in the treatment of locally advanced tumors in order to avoid multivisceral resection. Conclusion:Despite surgical resection remains as the most important aspect of the treatment of GISTs, adjuvant and neoadjuvant therapy with tyrosine kinase inhibitors have shown to both improve survival and resectability, respectively.

A preoperative risk score (PRS) to predict outcome of patients with intrahepatic cholangiocarcinoma treated by liver surgery could be clinically relevant. To assess accuracy for broadly adoption, external validation of predictive models on independent datasets is crucial. The objective of this study was to externally validate the score for prediction of long-term outcomes after liver surgery for intrahepatic cholangiocarcinoma proposed by Sasaki et al. and based on preoperative albumin, neutrophil-to-lymphocytes-ratio, CA19-9 and tumor size. METHODS Patients treated by liver surgery for intrahepatic cholangiocarcinoma at 11 international HPB centers from 2001 to 2018 were included in the external validation cohort. Harrell's c-index and Hosmer-Lemeshow analyses were used to test PRS discrimination and calibration. Kaplan-Meier curve for risk groups as described in the original study were displayed. RESULTS A total of 355 patients with 174 deaths during the follow-up period (median=41.7 months, IQR 32.8-50.6) were included. The median PRS value was 14.7 (IQR 10.7-20.6), with normal distribution across the cohort. A Cox regression on PRS covariates found coefficients similar to those of the derivation cohort, except for tumor size. Measures of discrimination estimated by Harrell's c-index was 0.61(95%CI:0.56-0.67) and Hosmer-Lemeshow p=0.175. The Kaplan-Meyer estimation showed reasonable discrimination across risk groups, with 5years survival rate ranging from 20.1% to 0%. CONCLUSION In this external validation cohort, the PRS had mild discrimination and poor calibration performance, similarly to the original publication. Nevertheless, its ability to identify different classes of risk is clinically useful, for a better tailoring of a therapeutic strategy.