1. ¹Department of Surgery, Lundberg Laboratory for Cancer Research, Sahlgrenska University Hospital, S-413 45 Göteborg, Sweden
2. ²Department of Pathology, Lundberg Laboratory for Cancer Research, Sahlgrenska University Hospital, S-413 45 Göteborg, Sweden
3. ³Department of Radiology, Lundberg Laboratory for Cancer Research, Sahlgrenska University Hospital, S-413 45 Göteborg, Sweden
4. ⁴Department of Oncology, Lundberg Laboratory for Cancer Research, Sahlgrenska University Hospital, S-413 45 Göteborg, Sweden

Correspondence: Dr B Nilsson, E-mail: bengt.nilsson@mbox353.swipnet.se

Received 9 July 2002; Revised 27 January 2003; Accepted 27 January 2003.

Abstract

Malignant gastrointestinal stromal tumours (GIST) have a poor prognosis. Since these tumours are resistant to conventional radiation and chemotherapy, surgery has been the mainstay of treatment. However, surgery is usually inadequate for the treatment of malignant GIST. Imatinib, a KIT tyrosine kinase inhibitor, has recently been found to have a dramatic antitumour effect on GIST. In this centre-based study of 17 consecutive patients with high-risk or overtly malignant GIST, imatinib was used in three different settings – palliatively, adjuvantly, and neoadjuvantly. The treatment was found to be safe and particularly effective in tumours with activating mutations of exon 11 of the KIT gene. Clinical response to imatinib treatment correlated morphologically to tumour necrosis, hyalinisation, and reduced proliferative activity. The value of neoadjuvant imatinib treatment was illustrated in one case.