Wenchang Yang1, Qian Liu2, Guole Lin3, Bo Zhang4, Hui Cao5, Yan Zhao6, Lijian Xia7, Fan Feng8, Zhiguo Xiong9, Junbo Hu10, Yingjiang Ye11, Kaixiong Tao1, Peng Zhang1. 1. Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. 2. Department of Colorectal Surgery, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China. 3. Department of General Surgery, Chinese Academy of Medical Sciences, Peking Union Medical College Hospital, Beijing, China. 4. Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu, China. 5. Department of Gastrointestinal Surgery, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. 6. Department of Gastric Surgery, Liaoning Cancer Hospital and Institute, Cancer Hospital of China Medical University, Shenyang, China. 7. Department of General Surgery, The First Affiliated Hospital of Shandong First Medical University, Jinan, China. 8. Department of Digestive Surgery, Xijing Hospital of Digestive Diseases, The Fourth Military Medical University, Xi'an, China. 9. Department of Gastrointestinal Surgery, Hubei Cancer Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. 10. Department of Gastrointestinal Surgery, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. 11. Department of Gastrointestinal Surgery, People's Hospital, Peking University, Beijing, China.
Abstract
BACKGROUND AND OBJECTIVES: This study aimed to characterize the efficacy of neoadjuvant imatinib in rectal gastrointestinal stromal tumors (GISTs) and the prognostic characteristics of patients after surgery. METHODS: Patients with rectal GISTs who received neoadjuvant imatinib between 2000 and 2019 were selected from 11 large-scale tertiary hospitals in China. The best response to neoadjuvant imatinib was assessed. Propensity score matching (PSM) was conducted to reduce confounders. Recurrence free survival (RFS) and overall survival (OS) were estimated using Kaplan-Meier method. RESULTS: Of the 100 patients, 75, 18, and 7 had a partial response (PR), stable disease (SD), and progressive disease (PD), respectively. The median tumor size decreased from 5 cm before treatment to 4 cm after treatment (p < 0.001). A total of 31 patients underwent genetic testing after surgery; 23 of patients with exon 11 mutation had PR and 2 had SD. One of the patients with exon 9 mutation had PR, 2 had SD, and 1 had PD. Two patients with the wild type GIST had PD. A total of 86 patients underwent surgery of which 85 underwent complete resection; 72 underwent anal preservation and 40 underwent local excision (LE). After PSM, patients who received neoadjuvant therapy had higher rates of LE (p = 0.001) and anal preservation (p = 0.033) than those of patients without neoadjuvant therapy. The median follow-up time was 37 months. Nine patients experienced recurrence and one patient died. The 3-year RFS and OS rates were 95.0% and 100%, respectively. After PSM, we found that there was no significant difference in RFS between patients who received or did not receive neoadjuvant therapy (p = 0.623). Univariate analysis showed postneoadjuvant tumor size (p = 0.469) and mitotic count (p = 0.294) were not associated with the RFS in patients who received neoadjuvant imatinib. CONCLUSIONS: Neoadjuvant imatinib can shrink rectal GIST size, increasing the possibility of complete resection and anal preservation. Further studies are warranted to understand the long-term outcomes of rectal GISTs in patients receiving neoadjuvant imatinib.
BACKGROUND AND OBJECTIVES: This study aimed to characterize the efficacy of neoadjuvant imatinib in rectal gastrointestinal stromal tumors (GISTs) and the prognostic characteristics of patients after surgery. METHODS:Patients with rectal GISTs who received neoadjuvant imatinib between 2000 and 2019 were selected from 11 large-scale tertiary hospitals in China. The best response to neoadjuvant imatinib was assessed. Propensity score matching (PSM) was conducted to reduce confounders. Recurrence free survival (RFS) and overall survival (OS) were estimated using Kaplan-Meier method. RESULTS: Of the 100 patients, 75, 18, and 7 had a partial response (PR), stable disease (SD), and progressive disease (PD), respectively. The median tumor size decreased from 5 cm before treatment to 4 cm after treatment (p < 0.001). A total of 31 patients underwent genetic testing after surgery; 23 of patients with exon 11 mutation had PR and 2 had SD. One of the patients with exon 9 mutation had PR, 2 had SD, and 1 had PD. Two patients with the wild type GIST had PD. A total of 86 patients underwent surgery of which 85 underwent complete resection; 72 underwent anal preservation and 40 underwent local excision (LE). After PSM, patients who received neoadjuvant therapy had higher rates of LE (p = 0.001) and anal preservation (p = 0.033) than those of patients without neoadjuvant therapy. The median follow-up time was 37 months. Nine patients experienced recurrence and one patientdied. The 3-year RFS and OS rates were 95.0% and 100%, respectively. After PSM, we found that there was no significant difference in RFS between patients who received or did not receive neoadjuvant therapy (p = 0.623). Univariate analysis showed postneoadjuvant tumor size (p = 0.469) and mitotic count (p = 0.294) were not associated with the RFS in patients who received neoadjuvant imatinib. CONCLUSIONS: Neoadjuvant imatinib can shrink rectal GIST size, increasing the possibility of complete resection and anal preservation. Further studies are warranted to understand the long-term outcomes of rectal GISTs in patients receiving neoadjuvant imatinib.