Imatinib mesylate may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Perioperative imatinib mesylate may shrink the tumor and may reduce the chance of relapse after surgery. This phase II trial is studying the effectiveness of perioperative imatinib mesylate in treating patients with locally advanced gastrointestinal stromal tumor.

Open-label trial in patients with locally advanced GISTs admitted to Department of Surgery, Beijing Cancer Hospital and Institute between April 2010 and May 2013 was carried out prospectively. Patients were planned to be treated with imatinib for duration of 6 months followed by surgical resection. Postoperative imatinib was planned to be administrated for 1.5 years. The primary end point was recurrent free survival (RFS) at 2 years; the secondary end points included objective response rate (ORR), surgical outcomes and drug safety.

Criteria:

• DISEASE CHARACTERISTICS:

  • Histologically confirmed gastrointestinal stromal tumor

    • Locally advanced disease: tumour size >5 cm and mitotic count >5/HPF; tumour size >10 cm; mitotic count >10/HPF
    • Potentially resectable disease: Multivisceral resection may be necessary to get sufficient margins

  • Documented c-kit (CD117) expression by immunohistochemical analysis of either initial core specimen or, if recurrent disease, from original tumor block

  • At least 1 site of measurable disease

  • No known brain metastases

• PATIENT CHARACTERISTICS:

Age:18 and over Performance status:ECOG 0-3 Life expectancy:Not specified

• Platelet count > 100,000/mm3
• Absolute neutrophil count > 1,500/mm3 Hepatic
• AST and ALT < 2.5 times upper limits of normal (ULN) (5 times ULN if hepatic metastases are present)
• Bilirubin < 1.5 times ULN
• No chronic active hepatitis
• No cirrhosis
• No other chronic liver disease Renal
• Creatinine < 1.5 times ULN
• No chronic renal disease Cardiovascular
• No New York Heart Association class III-IV cardiac disease
• No congestive heart failure
• No myocardial infarction within the past 6 months Immunology
• No active uncontrolled infection
• No known HIV positivity Other
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective barrier contraception during and for 3 months after completion of study treatment
• Must be medically fit to undergo surgery
• No other primary malignancy within the past 5 years except basal cell skin cancer, carcinoma in situ of the cervix, or a primary malignancy that is not currently clinically significant and does not require active intervention
• No gastrointestinal obstruction or major bleeding episode requiring immediate surgical intervention
• No uncontrolled diabetes
• No other severe or uncontrolled medical disease
• No significant history of noncompliance to medical regimens

PRIOR CONCURRENT THERAPY:

• No concurrent anticancer biologic agents
• More than 4 weeks since prior chemotherapy (6 weeks for nitrosourea or mitomycin) unless disease is rapidly progressing
• No concurrent anticancer chemotherapy
• At least 28 days since prior radiotherapy
• More than 2 weeks since prior major surgery except tumor biopsy Other
• At least 28 days since prior investigational drugs
• At least 28 days since prior imatinib mesylate
• No concurrent therapeutic doses of warfarin
• Concurrent low-molecular weight heparin or mini-dose warfarin (1 mg per day) prophylaxis is allowed