Impact of Surgical Modalities on Long-term Survival Outcomes of Patients with Duodenal Gastrointestinal Stromal Tumor.

BACKGROUND: The optimal surgical modality for duodenal gastrointestinal stromal tumor (GIST) remains undefined. The purpose of this study was to evaluate long-term survival outcomes of patients who underwent radical resection (RR) or limited resection (LR) of duodenal GIST. METHODS: A total of 325 patients identified from the Surveillance, Epidemiology and End Results (SEER) database who underwent surgery for duodenal GIST between 1986 and 2016 were classified into a LR group and a RR group based on the type of surgery received. Propensity score matching (PSM) was performed to minimize the selection bias in comparisons. Disease-specific survival (DSS) and overall survival (OS) were observed, and factors affecting the survival outcome were analyzed. RESULTS: In the entire cohort, 105 patients (32.3%) underwent RR and 220 (67.7%) received LR. Both the 5-year OS and DSS in RR group were significantly better than those in LR group (71.0% vs. 54.1%, P = 0.014; 66.6% vs. 49.1%, P = 0.025). PSM resulted in 95 pairs of patients, with long-term outcomes being comparable between the two groups. After adjusting covariates in the propensity matched cohort, the type of surgery still showed no significant impact on OS (hazard ratio [HR] 1.160; 95% confidence interval [CI] 0.662-2.033) and DSS (HR 1.208; 95% CI 0.686-2.128). CONCLUSIONS: Surgical modalities do not seem to have a significant impact on long-term survival outcomes of patients with duodenal GIST and should mainly depend on the tumor size and location.

Proposal of a new T-stage classification system for ampullary carcinoma based on Surveillance, Epidemiology and End Result (SEER) database.

BACKGROUND: Tumor size is still considered a useful prognostic factor in currently available tumor-node-metastasis (TNM) classification staging systems for most solid tumors, but the significance of tumor size on the prognosis of ampullary carcinoma remains controversial. The aim of the current study was to propose a new T-stage classification system for ampullary carcinoma to address the impact of tumor size on the prognostic outcome. METHODS: Using the Surveillance, Epidemiology, and End Results (SEER) database, we identified 1080 patients with ampullary carcinoma who underwent radical surgical resection between 2004 and 2015. Based on the results obtained from analysis of various clinicopathologic factors, a new T-stage classification system was proposed. RESULTS: Among the 1080 patients, 618 were men and 462 were women, with a median tumor size of 2.3 (range 0.1-12) cm. Using the 7th edition of the American Joint Committee on Cancer (AJCC) staging manual, we noticed significant differences in overall survival (OS) between T2 vs. T3 tumors (P < 0.001) and T3 vs. T4 tumors (P = 0.002), but failed to observe significant differences between T1 vs. T2 tumors (P = 0.498) in our pair-wise comparison. Using the newly developed T-stage classification system, we were able to differentiate significant differences in OS between T1 vs. T2 tumors (P = 0.032), T2 vs. T3 tumors (P < 0.001) and T3 vs. T4 tumor (P = 0.003) in all pair-wise comparisons. The c-index of the new staging system was 0.653 (95% CI: 0.629-0.677), showing a better discriminatory power than the 0.636 of the 7th AJCC staging system (95% CI: 0.612-0.660). CONCLUSIONS: The new T-stage classification system described herein can better differentiate prognostic outcomes after radical resection in patients with ampullary carcinoma by incorporating tumor size and depth of tumor infiltration.

Prognostic factors and benefits of adjuvant therapy for ampullary cancer following pancreatoduodenectomy: A systematic review and meta-analysis.

Ampullary cancer is a relatively rare gastrointestinal malignancy. The purpose of this study was to evaluate prognostic factors for survival and assess the benefits of adjuvant therapy following pancreaticoduodenectomy for this entity. Medline and EMBASE databases were searched to identify eligible studies from January 2000 to August 2019. Review Manager 5.3 statistical software was used for meta-analysis. 71 studies met the inclusion criteria and were included in the analysis for a total of 8280 patients. The median (range) 5-year overall survival and disease-free survival rates were 58% (32-82%) and 51% (28-73%) respectively. In meta-analysis, age >65 years at diagnosis, tumor size >20 mm, poor differentiation, pancreaticobiliary histotype, pT3-4 stage disease, presence of metastatic lymph node, number of metastatic nodes, perineural invasion, lymphovascular invasion, vascular invasion, pancreatic invasion, and positive surgical margins were independently associated with worse overall survival, whereas adjuvant therapy was associated with improved overall survival. In summary, in patients with ampullary cancer undergoing pancreaticoduodenectomy, tumor factors are the main predictors of worse survival and adjuvant treatment confers a survival benefit.