Background: Standard treatment for metastatic gastrointestinal stromal tumors (GISTs) is systemic therapy with imatinib. Surgery is performed to remove metastatic lesions to induce long-term remission or even curation. In other patients, surgery is performed to remove (focal) progressive or symptomatic lesions. The impact and long-term results of surgery after systemic therapy have not been clearly defined.
Methods: Between September 2001 and May 2010, all patients with metastatic GIST who underwent surgery for metastatic GIST after systemic therapy (that is, imatinib and sunitinib) at four Dutch specialized institutions were included. Primary end-points were progression-free survival (PFS) and overall survival (OS).
Results: All 55 patients underwent surgery after treatment with systemic therapy. At the last follow-up, tumor recurrence or progression was noted after surgery in 48% of the patients who responded on systemic therapy, and in 85% of the patients who were treated while having progressive disease. Median PFS and OS were not reached in the group of responders. In the non-responders group PFS and OS were median 4 and 25 months, respectively. Response on systemic therapy and a surgical complete resection were significantly correlated to PFS and OS.
Conclusions: Surgery may play a role in responding patients. In patients with progressive disease, the role of surgery is more difficult to distinguish in this retrospective analysis since PFS is short. Which patients benefit and whether this improves long-term outcome should be established in a multicentric randomized trial.