[Immunohistochemical expression of epidermal growth factor and its prognostic value for gastrointestinal stromal tumors]

Clinicopathological features and prognosis of mesenteric gastrointestinal stromal tumor: evaluation of a pooled case series

Background

Due to the extremely rare incidence, data of clinicopathological features and prognosis of mesenteric gastrointestinal stromal tumors (GISTs) are limited. Therefore, the aim of the present study was to investigate the clinicopathological features and prognosis of mesenteric GISTs.

Patients and Methods

Mesenteric GISTs cases were obtained from our center and from case reports and clinical series extracted from MEDLINE. Clinicopathological features and survivals were analyzed.

Results

A total of 114 mesenteric GISTs were enrolled in present study. The most common symptom was abdominal pain (20/72, 27.8%), followed by abdominal mass (13/72, 18.1%) and distention (9/72, 12.5%). Most tumors exceeded 10 cm in diameter (71/112, 63.4%), exceeded 5/50HPF in mitotic index (50/85, 58.8%), and were high risk (82/90, 91.1%). The five-year disease free survival (DFS) and disease specific survival (DSS) was 57.7% and 60.1%, respectively. Tumor size and mitotic index were associated with DFS and DSS. The distribution of tumor size, histological type, mitotic index and NIH risk category were significantly different between mesenteric and gastric GISTs. Prognosis of mesenteric GISTs was worse than that of gastric GISTs. However, multivariate analysis showed that location was not an independent prognostic factor for mesenteric and gastric GISTs.

Conclusions

Most mesenteric GISTs exceeded 10 cm in diameter, exceeded 5/50HPF in mitotic index and were high risk. Mesenteric GISTs differed significantly from gastric GISTs in respect to clinicopathologic features. Mitotic index and tumor size were prognostic factors for mesenteric GISTs. The prognosis were comparable between mesenteric and gastric GISTs.

Predictive value of p53 expression in the risk of malignant gastrointestinal stromal tumors: Evidence from 19 studies

The current published data on p53 expression and its predictive value in the risk of malignant gastrointestinal stromal tumors (GIST) has are inconclusive. To derive a more precise estimation of the correlation between p53 and the biological behavior of GIST, a meta-analysis was performed. Studies were identified by searching PubMed and Embase. Inclusion criteria were GIST patients, and the evaluation of p53 expression and risk of malignancy. The odds ratio (OR) for a positive rate of p53 in the benign group vs. that in the malignant group and the ORs for the positive rate of p53 in the National Institutes of Health (NIH) very low risk + low risk group (VL+L) vs. the NIH intermediate risk + high risk (I+H) group were calculated with a 95% confidence interval (CI) for each study as an estimation of the predictive value of p53. A total of 19 studies including 1163 patients were involved in this meta-analysis. The overall OR for the positive rate of p53 in the malignant group vs. the benign group revealed that significantly elevated risks of positive p53 in the malignant group were achieved (OR 0.14, 95% CI: 0.06-0.31, P<0.00001, P(heterogeneity)=0.86). Moreover, significantly elevated risks of correlation between p53 expression and the NIH I+H group were achieved in the comparison of the NIH VL+L group vs. the NIH I+H group (OR, 0.25; 95% CI, 0.17-0.38; P<0.00001, P(heterogeneity)=0.04). The results indicate that p53 expression correlates with poor prognosis in GIST and has a close relationship within the NIH I+H group.