Do tumours located in the left lower lobe have worse outcomes in lymph node-positive non-small cell lung cancer than tumours in other lobes?

Objectives: Although an association between prognosis and lobar location of lung cancer, particularly the left lower lobe (LLL), has been suggested, the certainty of such association remains controversial. The purpose of this study was to evaluate the impact of tumour lobar location on surgical outcomes as an independent prognostic factor for survival in our non-small cell lung cancer (NSCLC) patient series. Methods: We retrospectively reviewed 978 NSCLC patients who underwent complete resection in our hospital between 2000 and 2007. We statistically analysed the association between clinicopathological factors and clinical outcomes. Results: Among the 978 patients reviewed, the NSCLC was located in the LLL in 143 (14.6%) patients, and lymph node involvement was identified in 210 patients (21.5%). The 5-year overall survival rates of patients whose NSCLC was located in the LLL and in other lobes (non-LLL) were 73.1 and 74.3%, respectively, and showed no significant association (P = 0.86). On the other hand, the 5-year survival rates of patients whose NSCLC occurred in the LLL (n = 33) and non-LLL (n = 177) and with lymph node metastasis were 32.7 and 57.7%, respectively, and showed a significant association (P = 0.01). Therefore, we performed a more detailed analysis on the 210 NSCLC patients with lymph node metastasis. On multivariate analysis, we found that LLL tumour (P = 0.02), tumour size >3 cm (P = 0.02) and N status (P < 0.001) were significant independent predictors for survival. Conclusions: LLL tumours with lymph node metastasis are strongly associated with mortality in NSCLC patients. The location of the primary tumour may contribute in determining the optimal management strategy and accurate prediction of prognosis.