The size of consolidation on thin-section computed tomography is a better predictor of survival than the maximum tumour dimension in resectable lung cancer

Ground-glass opacity (GGO) is a preoperative prognostic factor in resectable lung cancer. However, the impact of GGO on the T factor in the TNM staging system remains unclear and the maximum tumour dimension is also an uncertain measurement for assessing the prognosis of early lung cancer with a mixture of consolidation and GGO. Thus, we sought to determine which the better prognostic factor was, the size of the consolidation on computed tomography scan or the conventional maximum tumour dimension. Between January 2004 and January 2011, 398 consecutive clinical stage IA lung cancer patients underwent surgical resection at our hospital. Univariate and multivariate analyses were performed by the logistic regression procedure to determine the relationship between pathological lymph node metastasis-positive status and clinical or radiological findings such as the maximum dimensions of consolidation and the tumour, the presence of air bronchogram, pleural indentation and the preoperative serum carcinoembryonic antigen (CEA) level. Of the 398 patients, 59 (14.8%) had pathological lymph node metastasis. Univariate analysis revealed four significant predictors of pathological nodal involvement: the presence of air bronchogram, the size of consolidation, the maximum tumour dimension and the preoperative CEA level (P < 0.01, respectively). In a multivariate analysis, the size of consolidation and the presence of air a bronchogram were significant predictors of nodal metastasis (P < 0.01, respectively). The maximum dimension of the consolidation was an independent unfavourable prognostic factor, regardless of the maximum tumour dimension. This could lead to the more accurate prediction of pathological lymph node metastasis with both GGO and consolidation.