During the operation, the dose of anesthetic drugs (propofol/ fentanyl /remifentanil and sevoflurane/ cisatracurium/ rocuronium) are adjusted to maintain the mean arterial pressure and heartbeat fluctuations within 20% of the baseline value and Entropy (or BIS) value at 40-60in both groups. The following patient data were recorded, the type of anesthesia, age at the time of surgery, preoperative Karnofsky performance status (KPS) score and functional capacity, the postoperative complications within 30 days (according Clavien-Dindo classification), ASA physical status scoress, tumor marker , tumor size, intraoperative blood loss/transfusion, duration of surgery, duration of anesthesia, total opioid (remifentanil/ fentanyl/ propofol) use, postoperative radiation therapy, postoperative chemotherapy, postoperative concurrent chemoradiotherapy, the presence of disease progression, and 6-month, 1-year, and 3-year overall survival and Karnofsky performance status score were recorded.
