Adjuvant Imatinib for GI Stromal Tumors: When and For How Long? [ONCOLOGY GRAND ROUNDS]

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice. A 45-year-old woman presented with syncope. She was severely anemic, with a hemoglobin level of 6 g/dL, and was found to have lower GI bleeding. A diagnostic colonoscopy was negative. A subsequent computed tomography scan of the abdomen and pelvis was performed, revealing a 3.2 x 3 x 2.9–cm contrast-enhancing right lower-quadrant mass arising from the wall of the ileum. There was no evidence of metastatic disease. The patient underwent laparotomy, and a 3.5-cm mass was resected with negative margins. Pathology revealed a GI stromal tumor with mixed spindle and epithelioid features involving the mucosa and submucosa (Fig 1A). The tumor cells were positive for CD117 (c-kit) (Fig 1B) and DOG-1(Fig 1C). There were eight to 10 mitoses per 50 high-power fields (Fig 1D). Molecular studies showed a 42-base pair deletion in exon 11 of the KIT gene that would delete all or part of codons 558 to 572 (V559_D572del) and would change the 558-encoding amino acid from Lys to A...
Source: Journal of Clinical Oncology - Category: Cancer & Oncology Authors: Tags: Oncology Grand Rounds Source Type: research