Long-term follow-up of patients with GIST undergoing metastasectomy in the era of imatinib - Analysis of prognostic factors (EORTC-STBSG collaborative study)

Background Long-term complete remissions remain a rare exception in patients with metastatic gastrointestinal stromal tumors (GIST) treated with IM (imatinib). To date the therapeutic relevance of surgical resection of metastatic disease remains unknown except for the use in palliative intent. Patients and methods We analyzed overall survival (OS) and progression-free survival (PFS) in consecutive patients with metastatic GIST who underwent metastasectomy and received IM therapy (n = 239). Results Complete resection (R0+R1) was achieved in 177 patients. Median OS was 8.7 y for R0/R1 and 5.3 y in pts with R2 resection (p = 0.0001). In the group who were in remission at time of resection median OS was not reached in the R0/R1 surgery and 5.1 y in the R2-surgery (p = 0.0001). Median time to relapse/progression after resection of residual disease was not reached in the R0/R1 and 1.9 years in the R2 group of patients, who were resected in response. No difference in mPFS was seen in patients progressing at time of surgery. Conclusions: Our analysis implicates possible long-term survival in patients in whom surgical complete remission can be achieved. Incomplete resection, including debulking surgery does not seem to prolong survival. Despite the retrospective character and likely selection bias, this analysis may help in decision making for surgical approaches in metastatic GIST.