Molecular response of gastrointestinal stromal tumour after treatment with tyrosine kinase inhibitor imatinib mesylate.
Bleeding from the tumour site is not uncommon during the treatment of gastrointestinal stromal tumours with imatinib mesylate. It might represent an early reaction of highly vascularised tumour tissue to receptor blockade. Although often requiring emergency surgery, this is not necessarily a deleterious sign. Slow tumour regression and cystic tissue alteration may follow. Using immunohistochemistry and consecutive resection specimens, it was shown that the number of mitoses decreased significantly and MIB-1 as a marker of cell proliferation could no longer be detected. In the few tumour cells still present, the magnitude of expression of the pathognomonic marker CD117 remained unchanged. Decreases in the size of tumours responding to imatinib mesylate cannot be expected to meet the World Health Organisation or RECIST (response evaluation criteria in solid tumours) criteria. This underlines the necessity of functional imaging by positron emission tomography, contrast enhanced magnetic resonance imaging, or magnetic resonance spectroscopy to assess the response to treatment.
Reichardt
P
P
Division of Medical Oncology, Hematology, and Tumour Immunology, Robert Roessle Hospital and Tumour Institute, Charité University Hospital, The Humboldt University at Berlin, D-13122 Germany.
Schneider
U
U
Stroszczynski
C
C
Pink
D
D
Hohenberger
P
P
D000328:Adult; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001549:Benzamides; D004791:Enzyme Inhibitors / Q000627:therapeutic use*; D005770:Gastrointestinal Neoplasms / Q000188:drug therapy* / Q000473:pathology; D006801:Humans; D000068877:Imatinib Mesylate; D008297:Male; D009362:Neoplasm Metastasis; D010879:Piperazines / Q000627:therapeutic use*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors*; D011743:Pyrimidines / Q000627:therapeutic use*; D017154:Stromal Cells; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D001549:Benzamides; D004791:Enzyme Inhibitors; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate; D011505:Protein-Tyrosine Kinases