The intrathoracic lymph node ratio seems to be a better prognostic factor than the level of lymph node involvement in lung metastasectomy of colorectal carcinoma

OBJECTIVES Data on thoracic lymph node involvement (LNI) in lung metastasis of colorectal cancer (CRC) are conflicting, with a 5-year overall survival (OS) ranging from 6 to 40%. We aimed to evaluate whether there are subgroups of patients according to the lymph node ratio (LNR). METHODS We retrospectively reviewed the data from 106 patients who underwent a thoracic procedure for CRC lung metastasis with pathologically proven thoracic LNI. RESULTS In the univariate analysis, the median OS was significantly poorer for a pN2 location of LNI (26 vs 16 months, P = 0.04), LNR ≥50% (30 vs 17 months, P = 0.005), high preoperative CEA (32 vs 16 months, P = 0.02), hepatic metastases (27 vs 11 months, P