Clinical Features of Ground Glass Opacity-Dominant Lung Cancer Exceeding 3.0 cm in the Whole Tumor Size.

BACKGROUND: Ground glass opacity (GGO)-dominant lung adenocarcinoma sized 3.0 cm or less in the whole tumor size is widely known to have an excellent prognosis and is regarded as early lung cancer. However, the characteristics and prognosis of lung cancer showing GGO exceeding 3.0 cm remains unclear.

METHODS: From 2002 through 2012, we reviewed 3,735 lung cancers that underwent complete resection at our institution. We identified 160 lung cancers (4.3%) showing GGO exceeding 3.0 cm on thin-section computed tomography and divided them into three types by the consolidation/tumor ratio (CTR) using cutoff values of 0.25 and 0.5. We compared the characteristics and prognosis among these types.

RESULTS: Type A (CTR, 0 to ≤0.25), type B (CTR, >0.25 to ≤0.5), and type C (CTR, >0.5 to <1.0) were found in 16 (10%), 37 (23%), and 107 lesions (67%), respectively. No lymph node metastasis was found in types A and B. Recurrence was not observed in types A and B. The 5-year overall survival and disease-free survival rates were both 100% in type A, both 97.2% in type B, and 88.4% and 66.7% in type C, respectively. Patients with type C had a significantly worse prognosis than those with the other types with respect to overall survival and disease-free survival.

CONCLUSIONS: A patient with GGO-dominant lung cancer exceeding 3.0 cm can be considered to be in a group of patients with nodal-negative disease and an excellent prognosis.