Clinicopathologic spectrum of gastro intestinal stromal tumours - experience at a tertiary care center

Gastrointestinal Stromal Tumours (GIST): Indian Experience of Rare Malignancy

GISTs are rare tumours of the GI tract arising from the intestinal cells of Cajal. Though various risk stratification systems have been proposed, none has been universally accepted. We audited the survival and recurrence patterns in our patients and evaluated clinicopathological features to identify prognostic factors affecting survival. We conducted a retrospective analysis of patients treated at our hospital from 1999 to 2012. Patient variables, clinicopathological factors and treatment variables were collected. Sixty-three patients were evaluated and treated at our institute of which 38 were non-metastatic. The most common site of origin was the stomach. On univariate analysis, presence of metastasis, male gender, high mitotic rate, non-gastric primary and epithelioid histology were significantly associated with poor overall survival. Tumour size > 10 cm, mitotic rate > 10/50 hpf and presence of necrosis significantly affected disease-free survival for non-metastatic patients. Multivariate analysis showed higher mitotic rate and non-gastric primary to correlate with worse outcome. In our experience, a high mitotic rate and non-gastric primary independently predicted a poor prognosis in GIST.

Gastrointestinal Stromal Tumors: A Clinicopathologic and Risk Stratification Study of 255 Cases from Pakistan and Review of Literature

PURPOSE

To describe the clinicopathological features of gastrointestinal stromal tumors (GIST) diagnosed in our section and to perform risk stratification of our cases by assigning them to specific risk categories and groups for disease progression based on proposals by Fletcher et al and Miettinen and Lasota.

MATERIALS AND RESULTS

We retrieved 255 cases of GIST diagnosed between 2003 and 2014. Over 59% were male. The age range was 16 to 83 years with a mean of 51 years. Over 70% occurred between 40 and 70 years of age. Average diameter of tumors was 10 cms. The stomach was the most common site accounting for about 40%. EGISTs constituted about 16%. On histologic examination, spindle cell morphology was seen in almost of 85% cases. CD117 was the most useful immunohistochemical antibody, positive in 98%. Risk stratification was possible for 220 cases. Based on Fletcher's consensus proposal, 62.3 gastric, 81.8% duodenal, 68% small intestinal, 72% colorectal and 89% EGISTs were assigned to the high risk category; while based on Miettinen and Lasota's algorithm, about 48% gastric, 100% duodenal, 76% small intestinal, 100% colorectal and 100% EGISTs in our study were associated with high risk for disease progression, tumor metastasis and tumor related death. Follow up was available in 95 patients; 26 were dead and 69 alive at follow up. Most of the patients who died had high risk disease and on average death occurred just a few months to a maximum of one to two years after initial surgical resection.

CONCLUSIONS

Epidemiological and morphologic findings in our study were similar to international published data. The majority of cases in our study belonged to the high risk category.