Cavity Wall Thickness in Solitary Cavitary Lung Adenocarcinomas Is a Prognostic Indicator.

BACKGROUND: Although cavitary lung cancers typically show thick-walled cavities on radiology, thin-walled cancers have recently been reported. However, the prognostic and pathologic differences between thin-walled and thick-walled variants are unclear. We reviewed detailed histologic features and survival outcomes of cavitary pulmonary adenocarcinomas to assess pathologic attributes, focusing particularly on cavity wall thickness.

METHODS: We studied 132 patients diagnosed with lung adenocarcinoma involving cavitary formation, as determined with high-resolution computed tomography or histology, between 1998 and 2007. Using receiver-operating characteristics curve analysis, we established a cutoff value for cavity wall thickness based on disease-specific survival. Cavitary adenocarcinomas were grouped into thick-walled or thin-walled types according to this cutoff, as measured by computed tomography.

RESULTS: The thick-walled group comprised lung adenocarcinoma patients with a cavity wall thickness of greater than 4 mm (n = 65); the thin-walled group comprised patients with a cavity wall thickness of 4 mm or less (n = 67). The thick-walled group had a higher frequency of solid predominant tumors (p < 0.01), vascular invasion (p < 0.001), lymphatic invasion (p < 0.01), necrosis (p < 0.001), obstructive pneumonia (p < 0.01), intracavity abscess (p < 0.01), and bronchiolar obstruction (p = 0.02). Lepidic predominant (p = 0.09) and papillary predominant patterns (p = 0.08) were more common in the thin-walled group. Multivariate analysis revealed cavity wall thickness to be an independent prognostic factor (p = 0.022).

CONCLUSIONS: The pathologic and prognostic implications of thick-walled cavities versus thin-walled cavities in lung carcinoma patients, defined according to our cutoff, were found to be distinct.