IS TUMOR ULCERATION AN INDEPENDENT RISK FACTOR IN GASTROINTESTINAL STROMA TUMORS michi.thali@gmail.com

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IS TUMOR ULCERATION AN INDEPENDENT RISK FACTOR IN GASTROINTESTINAL STROMA TUMORS

7

Austria

Oral or Poster

Gastrointestinal Stromal Tumors are rare, though representing the most common mesenchymal tumors of the GI-Tract. Surgical Treatment still represents the basis of the multimodal treatment modalities in these patients and offers the only curative option of cure. Lastly many clinical and paraclinical factors have been evaluated in these tumors to estimate prognosis, while mucosal ulceration has not been evaluated to this day.

From 195 patients, who have been operated between 2000 and 2022, demographic as well as clinicopathologic data and also informations about surgical and medical treatment (mainly imatinib) were collected and surveillance was analyzed. Survival data were calculated.

Surgery was performed in 112 men and 83 women with an average age of 64.7 years at time of operation. Primary GIST tumors were localized in the esophagus (3), stomach (127), duodenum (11), small bowel (41), large bowel and rectum (13). Average tumor diameter was 7.0 cm. In our patients we observed 86 tumors with mucosal ulceration whereas 107 tumors showed no ulceration. 5-years-survival rate was 85% in nonulcerated tumors and 74% in ulcerated GISTs (log Rank Test, p= 0.041). Risk groups (none, very low, low risk) demonstrated a significant higher 5-years-survival rate in comparison to the moderate/high risk group (88% versus 72%, p=0,046).

Conclusion: Our data demonstrate that besides known and established risk factors mucosal ulceration of the primary tumor may be an independent risk factor for prognosis in GIST.