Gastric GISTs. Personal experience.

BACKGROUND With term GIST is now defined a group of mesenchimal tumours of the gastrointestinal tract expressing immunopositivity for kit protein kinase (CD117). Surgical therapy remains the gold standard for these rare tumours. Imatinib Mesylate (STI-571) is a potent inhibitor of Kit Kinase activity and different reports demonstrated its efficacy in unresectable or metastatic Gists. AIM OF THE PAPER To value the incidence of GISTs among gastric mesenchimal neoplasms and analyzed their clinical presentation, prognostic parameters and surgical treatment. The response to Imatinib Mesylate in a case of metastatic GIST is then valued. METHODS Twelve cases of gastric mesenchimal neoplasms are retrospectively reviewed and tested by CD117 immmunopositivity identifyng 8 GISTs. The median follow-up was 37 (range7-120) months. We describe in details the case of a metastatic Gist treated for 15 months with Imatinib Mesylate. RESULTS The 67 per cent of mesenchimal gastric tumours were CD117+. Gastrointestinal bleeding was the most common presenting symptom. The 50% of patiens with malignant GISTS had a palpable abdominal mass at diagnosis. All tumors < 5 cm in diameter had a mitotic count (MC) <5/50 high-power fields (HPFs) except a case of high grade leiomyosarcoma. Surgical therapy was complete tumour resection with free margins. No recurrence was observed in lesions <5cm and < 5 mitosis/50 High Power Fields (HPFs). A good response to Imatinib Mesylate was reported in a metastatic GIST. CONCLUSION The surgeon's role in gastric Gist's treatment is to achieve a complete cancer resection with free margins. In advanced lesions, even in presence of hepatic metastases, surgical resection of the mass is indicated because is possible to obtain a stabilization or a partial remission with Imatinib Mesylate palliative treatment in some patients.