Surgical treatment of gastrointestinal stromal tumours combined with imatinib treatment: a retrospective cohort analysis.

Background: Targeted therapies changed the treatment concepts of gastrointestinal stromal tumours significantly. As only possibility to cure surgical resection is the cornerstone of therapy. Thus it is necessary to find out which patients will benefit most regarding modality (neo- or adjuvant) and duration of chemotherapy.

Methods: In a retrospective cohort analysis the medical records of all consecutive patients treated in the department of general and visceral surgery of the university hospital Tübingen between 2004 and 2015 were investigated. Recurrence and survival outcomes were calculated using the Kaplan-Meier method.

Results: Tumor location of GIST was gastric in 32, small bowel in 14, rectum in 3 and extraintestinal in 3 patients. Median tumor size was 46 mm. Median mitotic index was 4 per 50 hpf. Resection was achieved R0 in 46 patients, R1 in 4 patients and R2 in 2 patients. Mean overall survival was 58.9 months (range, 46-73 months). Mean recurrence free survival was 45.6 months (range, 36-57 months). Mean overall survival was 58.9 months (range, 46-73 months). Risk factors for recurrence were tumor location and high mitotic index Ki-67.

Conclusions: The prognosis of GIST after surgical resection is favourable. Survival prognosis are excellent. Analysis of KI-67 mitotic index predicted best oncologic outcome.