Neoadjuvant Imatinib Therapy Followed by Intersphincteric Resection for Low Rectal Gastrointestinal Stromal Tumors

Background/Aim: Intersphincteric resection (ISR) aims to preserve anal function in patients with very low rectal tumors. Here, we analyzed patients who underwent neoadjuvant imatinib therapy followed by ISR for low rectal gastrointestinal stromal tumors (GISTs). Patients and Methods: We retrospectively analyzed patients with low rectal GISTs who underwent neoadjuvant imatinib therapy and ISR between January 2013 and December 2015 at the University of Tokyo hospital. Results: The study included 4 men and 1 woman, with a median age of 67 years (range= 45-67). All patients received 400 mg of neoadjuvant imatinib once daily for the median duration of 4 months (range= 3-12). Microscopically, R0 resection was performed in 4 patients, and R1, in 1 patient. There was 1 recurrence event during the median follow-up duration of 35 months. Conclusion: Neoadjuvant imatinib therapy and ISR for low rectal GISTs is a challenging, but promising, alternative to achieve complete resection margins and preserve anal function.