Study objectives: To define characteristics of surgically curable, early cancers of the lung, we retrospectively studied relationships between thin-section CT (TS-CT) scans, pathologic features, and outcome data in 287 patients with resected small-diameter (< 20 mm) peripheral lung carcinoma. Cases included 260 adenocarcinomas, 16 squamous cell carcinomas, 6 small cell carcinomas, 3 large cell carcinomas, and 2 others.
Measurements and results: All tumors were classified by tumor shadow disappearance rate (TDR) on TS-CT as having either an "air-containing" or "solid-density" pattern. Adenocarcinomas are typically classified into these patterns. Air-containing patterns (n = 136) showed 1% pleural involvement and 2% vascular invasion, with no lymphatic permeation by pathology. Solid-density patterns (n = 124) showed 34% pleural involvement, 42% vascular invasion, and 29% lymphatic permeation. No cases of relapse or death were observed in cases with the air-containing pattern, in contrast to the high relapse and death rate in solid-density cases (p < 0.0001). All non-adenocarcinoma cases (n = 25) had a solid-density pattern, with 4% pleural involvement, 52% vascular invasion, and 44% lymphatic permeation. The overall 5-year survival rate for non-adenocarcinoma was 60%, similar to that for solid-density adenocarcinoma.
Conclusions: When peripheral lung cancers < 20 mm in diameter show air-containing patterns on TS-CT images, surgical outcomes may be favorable with curable disease.