Management of liver metastases of gastrointestinal stromal tumors (GIST).

Introduction: Liver metastases (LM) are crucial prognostic manifestation of gastrointestinal stromal tumors (GIST). With the advent of tyrosine kinase inhibitors (TKI), management of metastatic GIST has radically changed. Long clinical follow-up provides an increased proportion of GIST patients with LM who are candidates for potentially curative therapy.
Material and Methods: Patients who underwent treatment for liver metastases of GIST between 2000-2009 in our department were included in the study. Mean follow-up was 84 months (range 40-145) months. In retrospective analysis we investigated clinical, macro-/microscopic and immunohistochemical criteria, surgical, interventional and TKI therapy as well.
Results: In 87 GIST-patients we identified 25 (29%) patients with metastatic disease. Of these, 12 patients (14%) suffered from LM with a mean age of 60.5 (range, 35-75) years. Primary GIST were located at stomach (n = 4, 33%) or small intestine (n = 8, 67%); all of them expressed CD117 and/or CD34. LM were multiple (83%), distributed in both lobes (67%). They were detected synchronously with primary tumor in 33% and metachronously in 77%. All patients with liver involvement were considered to treatment with TKI. LM were resected (R0) in 4 patients (33%). In recurrent (2/4) and TKI resistant cases, interventional treatment (radiofrequency ablation) and TKI escalation were carried out. During a median follow-up of 84 months (range 30-152), 2 patients died (16.5%) for progressive disease and one patient for other reasons. Nine patients (75%) were alive.
Conclusion: Treatment of LM from GIST needs a multimodal approach. TKI-therapy is required at any case. In case of respectability, surgery must be carried out. In unresectable cases or recurrent/progressive disease, interventional treatment or TKI escalation should be considered. Therefore, these patients need to be treated in experienced centres, where multimodal approaches are established.