[A Large Gastric Gastrointestinal Stromal Tumor Successfully Treated with Neoadjuvant Imatinib Followed by Surgery-A Case Report].

Neoadjuvant imatinib may prevent tumor rupture and the need for extended surgery by reducing the tumor size by approximately 35%, especially for large gastric gastrointestinal stromal tumors(GISTs), as shown in a previous phase Ⅱ study (Kurokawa et al. BJC 2017); however, the use ofneoadjuvant imatinib is not prevalent in clinical practice. Herein, we report a large gastric GIST that was successfully treated with neoadjuvant imatinib. A 74-year-old woman complained ofabdominal pain, and abdominal computed tomography(CT)revealed a 14 cm oval tumor in the left upper abdominal cavity. Gastric biopsy revealed that the tumor was a GIST. The patient also had a small lung tumor that was diagnosed as a primary lung carcinoma in the right upper lobe. We performed neoadjuvant imatinib for 6 months as the primary treatment. After 7 months ofimatinib administration, CT revealed that the GIST decreased in size but the lung cancer was slightly enlarged. Therefore, we performed right upper lung lobectomy and continued imatinib therapy for an additional 3 months. After a total of9 months ofneoadjuvant imatinib treatment, we performed partial gastrectomy combined with splenectomy without tumor rupture. The patient is scheduled to continue imatinib therapy for a total of 3 years.