Perioperative Patient Factors Related to 2-Year Outcome after Esophageal Cancer Surgery: A Retrospective Cohort Study

Background: Surgical treatment for esophageal cancer is major invasive surgery. Recently, opioids have been implicated in the promotion of cancer recurrence and metastasis because of their immunosup-pressive effects. However, it has not been fully evaluated whether the intraoperative use of opioids is directly correlated with postoperative prognosis in the clinical setting. Therefore, this study aimed to identify perioperative factors related to postoperative complications and 2-year survival in patients undergoing esophageal cancer surgery. Methods: We retrospectively reviewed 105 patients who underwent surgery for esophageal cancer at Kagoshima University Hospital from January 2013 to December 2017. Patient parameters were compared between survivors and non-survivors for 2 years after surgery. Results: The 2-year survival rate after esophageal cancer surgery was 76.2% (80 survivors vs. 25 non-survivors). The incidence of postoperative pneumonia within 7 days after surgery was significantly higher in non-survivors compared with survivors (36.0% vs. 16.3%; odds ratio, 2.90; 95% confidence interval, 1.06 - 7.96, P < 0.05). Pneumonia was associated with postoperative metastasis (odds ratio, 3.00; 95% confidence interval, 1.117 - 8.072, P = 0.029). The intraoperative dosage of opioids calculated as fentanyl equivalents was not correlated with any postoperative complications or 2-year survival. The preoperative albumin level and neutrophil-lymphocyte ratio were associated with the incidence of postoperative pneumonia. Conclusions: Postoperative pneumonia may be a possible predictor of 2-year prognosis in patients after esophageal cancer surgery, and is not correlated with intraoperative use of opioids. Preoperative physical status including immune and nutrient states may be more important for postoperative prognosis after esophageal cancer surgery.