Transanal versus nontransanal surgery for the treatment of primary rectal gastrointestinal stromal tumors: a 10-year experience in a high-volume center

Background: Rectal gastrointestinal stromal tumor (GIST) is a rare digestive disease that has a distinct malignant tendency compared to that of gastric-derived GIST. At present, there is still no standard, and the surgical approach to rectal GIST is controversial. Methods: The clinicopathological data and prognosis of rectal GIST patients admitted to the Sixth Affiliated Hospital of Sun Yat-sen University from 1998.01.01 to 2018.12.31 were collected retrospectively. All cases were divided into either the transanal (TA) group or the nontransanal (NTA) group. Results: A total of 537 GIST cases were treated in 10 years, including 82 rectal GIST cases (64 cases underwent surgical resection, including 29 cases in the TA group and 35 cases in the NTA group). Preoperative neoadjuvant therapy (P=0.003), postoperative adjuvant therapy (P=0.017), operative time (P=0.013), blood loss (P=0.038), anus-preserver (P=0.048), 30-day complication rate (P=0.000), time to flatus (P=0.036), hospital stays (P=0.011), distance from the anus (P=0.047), tumor size (P=0.002), mitotic count (P=0.035) and National Institutes of Health (NIH) criteria (P=0.000) were significantly different between these two groups (all P<0.05). The median follow-up time was 41 (range, 1-122) months. Twelve patients had recurrence and metastasis, and 4 patients died. The 5-year disease-free survival (DFS) and overall survival (OS) were 74.4% and 91.2%, respectively, in the whole group. There were no statistically significant differences between the TA group and the NTA group at 5-year DFS (81.3% vs. 79.0%, P=0.243) and OS (88.7% vs. 93.3%, P=0.308). Conclusions: In the treatment of rectal GIST, TA resection has a minimally invasive effect, less postoperative complications, high anal sphincter preservation rate, and R0 resection rate and a better prognosis. How to improve the proportion of neoadjuvant therapy and choose the appropriate cases for TA surgery is still a challenge.