Abstract:Objective To systematically evaluate the risk factors for post-operative pulmonary infection (PI) in elderly patients with esophageal cancer. Methods China National Knowledge Infrastructure (CNKI), Wanfang database, CBM, PubMed, EMbase, Web of Science, Cochrane, Mediline and EBSCO were searched, studies (including case-control study and cohort study) on risk factors for post-operative PI in elderly patients with esophageal cancer published from the establishment of the database to January 4, 2021 were collected for systematic evaluation. Results A total of 18 literatures were included, Meta-analysis showed that independent risk factors for post-operative PI in elderly patients with esophageal cancer were pre-operative smoking history (OR, 2.45[95%CI, 1.93-3.10]), chronic obstructive pulmonary disease (OR, 2.64[95%CI, 1.83-3.83]) and diabetes mellitus (OR, 3.06[95%CI, 2.20-4.24]) in case-control study as well as pre-operative smoking history (OR, 6.07[95%CI, 1.75-21.00]) and diabetes mellitus (OR, 3.26[95%CI, 1.78-5.97]) in cohort study, intra-operative recurrent laryngeal nerve injury (OR, 2.36[95%CI, 1.54-3.62]), operation time>4 hours (OR, 3.09[95%CI, 1.43-6.67]), operation time>3 hours (OR, 1.87[95%CI, 1.10-3.16]) and single lung ventilation (OR, 2.58[95%CI, 1.75-3.82]) in case-control study as well as intra-operative recurrent laryngeal nerve injury (OR, 3.34[95%CI, 2.01-5.55]) in cohort study (all P < 0.05). Descriptive analysis showed that low body mass index, old age and malnutrition were the risk factors of post-operative PI in elderly patients with esophageal cancer. Conclusion Smoking history, chronic obstructive pulmonary disease, diabetes mellitus, low body mass index, old age, malnutrition, recurrent laryngeal nerve injury, and single lung ventilation are independent risk factors for post-operative PI in elderly patients with esophageal cancer.