[Stromal gastrointestinal tumors: retrospective study of 24 cases]

Gastrointestinal stromal tumors (GIST) are the most common digestive sarcomas. They develop in most cases in the stomach and small intestine, more rarely rectum, colon, esophagus or mesentery. These tumors typically express the phenotype CD117/KIT + and CD34 +.

To evaluate epidemiologic, clinical, pathologic, therapeutic, characteristics and evaluative pattern of gastrointestinal tumor treated in our surgical department.

We collected 24 cases of GIST (confirmed by the positivity of CD 117 and/or CD 33) treated between 1997 and 2010 in the department of surgery B of Charles Nicolle's Hospital. We analyzed demographic characteristics, clinic pattern, investigations treatment and therapeutic variables of our patients. We calculated the survival rate and identified prognostic predictive factors of survival.

Our retrospective study interested, during 13 years, 24 patients presenting GIST with a median age of 66 years and a sex ratio of 0.8. The median time for diagnosis was two months (3 days to 24 months). Abdominal pain, gastrointestinal bleeding and vomiting were the most common symptoms. The endoscopic appearance was tumor arising from muscular layer found in the stomach (13/24 cases; 54%), small bowel in four cases (16.5%) and duodenal or rectum three patients (12,5 %). Twenty three within 24 patients underwent surgical resection with R0 in 20/23 cases. Three patients were treated with neoadjuvant imatinib for an average of 12 months, one patient had adjuvant treatment and four patients in locoregional evolutive tumor and / or metastatic. The overall survival was 70% at one year and 65% at two years with a pejorative impact, in univariate analysis of abdominal pain, asthenia, anorexia, weight loss, cytonuclear atypia, tumor size ≥ 10 cm and a mitotic index ≥ 5/50. Multivariate analysis showed that tumor size (Hazard Ratio = 6 if size ≥ 10 cm 95% CI [1,539-24,017]) and weight loss (Hazard Ratio = 7 95% CI [1,664-29,100]) were influential factors on overall survival and recurrence-free survival.

The prognostic predictive factors identified were the size of tumor ≥ 10cm and the mitotic index.