What’s in a (tumor) cavity?

Cavity formation, or cavitation, is a recognized feature of lung cancer, typically occurring spontaneously in squamous cell carcinomas. One large study found that approximately one-sixth of primary bronchial carcinomas demonstrated cavitation (1). After treatment with angiogenesis inhibitors, other lung cancer types, for example adenocarcinomas, and tumors metastatic to the lung, can also cavitate. The prognostic and therapeutic implications of cavitation are controversial, since some studies have shown a positive association of outcomes with cavitation (2), others not (3,4), whereas others have found a marginal association of cavitation with outcome (5).