J Korean Soc Coloproctol.  2011 Jun;27(3):147-152. 10.3393/jksc.2011.27.3.147.

Efficacy of Imatinib Mesylate Neoadjuvant Treatment for a Locally Advanced Rectal Gastrointestinal Stromal Tumor

• Yoon KJ
• Kim NK
• Lee KY
• Min BS
• Hur H
• Kang J
• Lee S

• KMID: 2198763
• DOI: http://doi.org/10.3393/jksc.2011.27.3.147

Abstract

Surgery is the standard treatment for a primary gastrointestinal stromal tumor (GIST); however, surgical resection is often not curative, particularly for large GISTs. In the past decade, with imatinib mesylate (IM), management strategies for GISTs have evolved significantly, and now IM is the standard care for patients with locally advanced, recurrent or metastatic GISTs. Adjuvant therapy with imatinib was recently approved for use, and preoperative imatinib is an emerging treatment option for patients who require cytoreductive therapy. IM neoadjuvant therapy for primary GISTs has been reported, but there is no consensus on the dose of the drug, the duration of treatment and the optimal time of surgery. These are critical because drug resistance or tumor progression can develop with a prolonged treatment. This report describes two cases of large rectal malignant GISTs, for which a abdominoperineal resection was initially anticipated. The two patients received IM preoperative treatment; we followed-up with CT or magnetic resonance imaging to access the response. After 9 months of treatment, a multi-disciplinary consensus that maximal benefit from imatinib had been achieved was reached. We determined the best time for surgical intervention and successfully performed sphincter-preserving surgery before resistance to imatinib or tumor progression occurred. We believe that a multidisciplinary team approach, considerating the optimal duration of therapy and the timing of surgery, is required to optimize treatment outcome.

Keyword

Gastrointestinal stromal tumors; Imatinib; Ultralow anterior resection; Coloanal anastomosis; Neoadjuvant treatment

MeSH Terms

Benzamides
Consensus
Drug Resistance
Gastrointestinal Stromal Tumors
Humans
Imatinib Mesylate
Magnetic Resonance Imaging
Mesylates
Neoadjuvant Therapy
Piperazines
Pyrimidines
Treatment Outcome
Benzamides
Mesylates
Piperazines
Pyrimidines