As I described in a post last year, one of the common features of angiogensis inhibitors is that lesion often cavitate, shrinking not only from the outside in, but hollowing out and dying from the inside out.

Tumor cavitation has been one of the issues we really haven't discussed but that has been a challenging question as we test more and more anti-angiogenic drugs, which target the tumor blood supply, in the setting of lung cancer. Since we started testing these agents, we've noticed that in addition to sometimes increasing the rate of tumor shrinkage, many patients who receive anti-angiogenic drugs develop cavitation, or a response on the inside of the tumor that leaves the rim of the tumor intact, as shown here: