Follow-up
Patients were reviewed monthly for 6 months after surgery. Then they were followed up every 3 moths for up to 2 years after surgery, then every 6 moths for up to 5 years, and then every year or until death. A physical examination, laboratory tests including serum CA19-9 and CEA levels, and abdominal ultrasound were performed at each visit, whereas chest and abdominal computed tomography or abdominal magnetic resonance imaging were routinely obtained every 6 moths. For patients with suspected recurrence or metastasis, imaging examinations were performed at any time. The OS was calculated from the day of surgery until time of death or final follow-up. The RFS was defined as the interval from the surgical time until tumor recurrence or the last follow-up. The median follow-up were 51 months (range: 1-126) for OS and 49 months (range: 1-126) for RFS, respectively. The date of the final follow-up was March 30, 2022.