Difference Between ‘Lung Age’ and Real Age as a Novel Predictor of Postoperative Complications, Long-term Survival for Patients With Esophagus Cancer After Minimally Invasive Esophagectomy

Background This study aimed to investigate whether difference between ‘lung age’ and real age (L-R) could be useful for the prediction of postoperative complications and long-term survival in patients with esophageal cancer followed by minimally invasive esophagectomy (MIE).Methods This retrospective cohort study included 625 consecutive patients who had undergone MIE. ‘Lung age’ was determined by the calculation method proposed by Japanese Respiratory Society. According to L-R, patients were classified into three groups: group A: L-R≦ 0 (n =104), group B:15>L-R>0 (n =199), group C:L-R≥15 (n = 322). Clinicopathological factors, postoperative complications evaluated by comprehensive complications index (CCI) and overall survival were compared between the groups. A CCI value >30 indicated a severe postoperative complication.Results Male, smoking status, smoking index, chronic obstructive pulmonary disease, American Society of Anesthesiologists status, lung age, and forced expiratory volume in 1 s were associated with group classification. CCI values, postoperative hospital stays, and hospital cost were significantly different among groups. Multivariate analysis indicated that L-R, coronary heart disease, 3-field lymphadnectomy were significant factors for prediction of CCI value>30. Regarding overall survival, there was a significant difference between group A and group B+C (log rank test: P= 0.03). Conclusions Esophageal cancer patients with impaired pulmonary function had a higher risk of severe postoperative complications and poorer prognosis than those with normal pulmonary function. Difference between ‘lung age’ and ‘real age’ is a novel predictor of severe postoperative complications and long-term survival and has extensive clinical value.