Hiroyuki Sakurai1, Kazuo Nakagawa2, Shun-Ichi Watanabe2, Hisao Asamura3. 1. Division of Thoracic Surgery, National Cancer Center Hospital, Tokyo, Japan. Electronic address: hsakurai@ncc.go.jp. 2. Division of Thoracic Surgery, National Cancer Center Hospital, Tokyo, Japan. 3. Division of Thoracic Surgery, National Cancer Center Hospital, Tokyo, Japan; Department of General Thoracic Surgery, Keio University Graduate School of Medicine, Tokyo, Japan.
Abstract
BACKGROUND: Subcentimeter lung cancers are still rare, and their pathobiologic behavior and management have not yet been fully clarified. METHODS: From 1993 through 2011, 291 patients with resected lung cancers 1.0 cm or less in diameter were studied regarding their clinicopathologic characteristics. According to appearance on high-resolution computed tomography (HRCT), the tumors were classified into four types: type 1 (n = 50), nonsolid ground-glass opacity (GGO) lesion; type 2 (n = 89), part-solid GGO lesion including 50% or more GGO within the lesion; type 3 (n = 62), part-solid GGO lesion including less than 50% GGO within the lesion, and type 4 (n = 90), solid lesion. RESULTS: Although none of types 1 to 3 tumors had lymph node metastases, these were found in 10% of type 4 tumors. Recurrence was observed in 13 patients, almost all of whom had type 4 tumors. The lone exception was a patient with a type 3 tumor in whom local recurrence developed on a surgical staple line. The 5-year overall survival rates were 100% in type 1 and type 2, 98% in type 3, and 88% in type 4. Type 4 had a significantly worse prognosis than the other types. CONCLUSIONS: Subcentimeter lung cancers with a GGO component on HRCT (types 1 to 3) can be considered "early" lung cancers. In these cases, limited resection may be warranted to achieve a cure because they had no lymph node metastasis. By contrast, lobectomy should still be considered the standard operation of choice for type 4 tumors.
BACKGROUND: Subcentimeter lung cancers are still rare, and their pathobiologic behavior and management have not yet been fully clarified. METHODS: From 1993 through 2011, 291 patients with resected lung cancers 1.0 cm or less in diameter were studied regarding their clinicopathologic characteristics. According to appearance on high-resolution computed tomography (HRCT), the tumors were classified into four types: type 1 (n = 50), nonsolid ground-glass opacity (GGO) lesion; type 2 (n = 89), part-solid GGO lesion including 50% or more GGO within the lesion; type 3 (n = 62), part-solid GGO lesion including less than 50% GGO within the lesion, and type 4 (n = 90), solid lesion. RESULTS: Although none of types 1 to 3 tumors had lymph node metastases, these were found in 10% of type 4 tumors. Recurrence was observed in 13 patients, almost all of whom had type 4 tumors. The lone exception was a patient with a type 3 tumor in whom local recurrence developed on a surgical staple line. The 5-year overall survival rates were 100% in type 1 and type 2, 98% in type 3, and 88% in type 4. Type 4 had a significantly worse prognosis than the other types. CONCLUSIONS: Subcentimeter lung cancers with a GGO component on HRCT (types 1 to 3) can be considered "early" lung cancers. In these cases, limited resection may be warranted to achieve a cure because they had no lymph node metastasis. By contrast, lobectomy should still be considered the standard operation of choice for type 4 tumors.