BACKGROUND AND OBJECTIVE: The Japanese Respiratory Society recently proposed 'lung age' as an easily understood concept of respiratory function. In this study, we evaluated whether 'lung age' could be a useful predictor of post-operative respiratory complications and survival patients with lung cancer treated surgically. METHODS: The study recruited 308 patients who underwent surgery for primary non-small-cell lung cancer. All patients had preoperative pulmonary function testing. 'Lung age' was determined using the methods advocated by the Japanese Respiratory Society. Based on the difference between 'real age' (R) and 'lung age' (L), patients were classified into five groups: group A: R-L > 15 (n = 37), B: 5 < R-L <or= 15 (n = 50), C: -5 <or= R-L <or= 5 (n = 73), D: -15 <or= R-L < -5 (n = 54), E: -15 > R-L (n = 94). Clinicopathological factors, post-operative respiratory complications and survival were compared between the groups. RESULTS: Gender, smoking status and index, histology, operative approach and FEV(1) were significantly associated with the group classification. The incidence of complications was significantly higher in group E compared with other groups (P = 0.003). Multivariate analysis showed that the group classification by 'lung age' was an independent predictor of post-operative respiratory complications (P = 0.02). Overall survival differed significantly between the groups (P = 0.03). CONCLUSIONS: 'Lung age' could be useful for the prediction of post-operative respiratory complications and survival in patients with lung cancer treated surgically.
BACKGROUND AND OBJECTIVE: The Japanese Respiratory Society recently proposed 'lung age' as an easily understood concept of respiratory function. In this study, we evaluated whether 'lung age' could be a useful predictor of post-operative respiratory complications and survival patients with lung cancer treated surgically. METHODS: The study recruited 308 patients who underwent surgery for primary non-small-cell lung cancer. All patients had preoperative pulmonary function testing. 'Lung age' was determined using the methods advocated by the Japanese Respiratory Society. Based on the difference between 'real age' (R) and 'lung age' (L), patients were classified into five groups: group A: R-L > 15 (n = 37), B: 5 < R-L <or= 15 (n = 50), C: -5 <or= R-L <or= 5 (n = 73), D: -15 <or= R-L < -5 (n = 54), E: -15 > R-L (n = 94). Clinicopathological factors, post-operative respiratory complications and survival were compared between the groups. RESULTS: Gender, smoking status and index, histology, operative approach and FEV(1) were significantly associated with the group classification. The incidence of complications was significantly higher in group E compared with other groups (P = 0.003). Multivariate analysis showed that the group classification by 'lung age' was an independent predictor of post-operative respiratory complications (P = 0.02). Overall survival differed significantly between the groups (P = 0.03). CONCLUSIONS: 'Lung age' could be useful for the prediction of post-operative respiratory complications and survival in patients with lung cancer treated surgically.