Surgical resection of residual disease in initially inoperable imatinib-resistant/intolerant gastrointestinal stromal tumor treated with sunitinib.

AIM: Sunitinib malate therapy in inoperable and/or metastatic gastrointestinal stromal tumor (GIST) resistant to imatinib mesylate may facilitate surgical removal of residual disease. We explored this possibility in the course of treating patients as part of a treatment-use trial, the objective of which was to provide access to sunitinib treatment. METHODS: Four patients with inoperable and/or metastatic GIST resistant to imatinib who had responded to sunitinib therapy administered at a starting dose of 50 mg daily in 6-week cycles of 4 weeks on treatment followed by 2 weeks off underwent surgical removal of residual disease. Disease progression on or clinical response to treatment was defined based on Response Evaluation Criteria in Solid Tumors. RESULTS: In three of four cases it was possible to perform macroscopically complete resection of residual disease, resulting in surgical complete clinical responses, two with durations of 13 months. The fourth patient achieved a dramatic partial response to sunitinib that required emergency surgical resection of the necrotic tumor mass, with the partial response having been maintained for 15 months. In all cases, viable GIST cells were detected histologically in the resection specimens, and sunitinib treatment was resumed post-surgery. None of the patients experienced any postoperative complications during 13-16 months of follow-up. CONCLUSIONS: Combining sunitinib treatment with surgical removal of residual disease may allow selected imatinib-resistant GIST patients who have shown a favorable response to sunitinib to achieve complete and sustained remission or durable control of previously progressive disease beyond that expected for sunitinib treatment alone.

The clinical characteristics and the role of surgery and imatinib treatment in patients with liver metastases from c-Kit positive gastrointestinal stromal tumors (GIST).

The purpose of this study was to analyze the clinical features of the group of c-KIT positive GIST patients with liver metastases evaluated and treated in two referral institutions as well as to attempt to define the role of surgery in the management of GIST given the emergence to imatinib as an important part of treatment strategy in GIST patients. Between August 2001 and December 2002, 90 patients with c-KIT positive GIST were referred to our institutions. In 50 patients metastatic disease were disclosed. Of these, 35 patients (35/50; 70%) were rendered to have liver metastases and therefore offered imatinib or surgical therapy depend on CT assessment. The median follow-up of these 35 patients calculated from the time of first operation was 23 months (range 3-246 months). Male patients comprised the majority of patients (70%) with liver metastases. In 14 patients (40%) the metastases were confined only to the liver, in the others 21 patients (60%) the liver metastases were accompanied by intraperitoneal dissemination (17; 48.6%) or local recurrences (4; 11.4%). The period of time between the diagnosis of primary lesion and occurring liver metastases ranged from 0 to 164 months (median time of liver metastases presentation was 16 months for patients undergone primary curative surgery). The liver metastases were estimated as resectable in 3 cases (8.6%) and hepatic resection of all gross lesions was possible. Group of 32 patients with unresectable liver involvement was considered to treatment with imatinib. The median time of imatinib treatment for survivors is 7.5 months (range: 3.5-18.5 months). Twelve patients (37.5%) demonstrated partial response (PR) and 16 patients (50%) stable disease (SD) according to RECIST criteria. We did not observe any complete response (CR). At median follow-up 7 months, 32 of 35 patients (91.4%) were alive, 3 patients (8.6%)remained free of disease and 28 patients (87.5%) remained on imatinib treatment and have maintained disease although with partial response or stabilization only. Radical surgical resection remains the only possibility of cure for GIST patients because the complete response after imatinib therapy is restricted to a few patients only. However, despite the advanced metastatic disease, approximately 90% of patients are alive and continue imatinib treatment with median follow-up time more than 7 months. Surgery in combination with adjuvant imatinib treatment may result in improved survival with patients with advanced GIST.