Neoadjuvant and Adjuvant Therapy with Imatinib for Locally Advanced Gastrointestinal Stromal Tumors in Eastern Indian Patients

Background: Imatinib mesylate is able to at least modify the course of gastrointestinal stromal tumours (GISTs). Neoadjuvant use for locally advanced lesions is evolving as a new treatment paradigm in this hitherto universally fatal disease. Methods and Results: The study patients with locally advanced GIST received neoadjuvant and adjuvant imatinib mesylate. Response was noted as per the RECIST protocol and overall progression free survival was reported. Of 19 patients (mean age 38.5 years, range 26 yrs to 64 yrs) studied, 13 achieved partial response (PR) and 6 a stationary disease (SD) on preoperative imatinib. Histopathological evaluation and grading of responses revealed only moderate and low grade pathological response after imatinib. R0 resection was possible in 13/19 and R1 in 6/19. Imatinib was well tolerated and adverse reactions were minimal. Post operative complications of surgery were not out of the ordinary for a surgical series featuring extensive abdominal surgery. Conclusion: Preoperative imatinib in locally advanced GIST seems to be a reasonable option for locally advanced GIST patients and enough downstaging to allow a resection with microscopically negative margins can be expected in a fairly good proportion of patients.