October 30, 2006 -- Our current cancer paradigm is very simple indeed. It states that one cell becomes malignant and then gives rise to a local tumor. At some point, that tumor will start spreading radially outward from the target, first breaking through some local obstacles, and then growing into the surrounding tissue. Later, the tumor will also spread through disconnected seeding, or metastasis, to other organs. This model governs the current clinical practice. In Part III, we will discuss the new stem cell paradigm of cancer, which solves some problems of the current model, though it raises its own set of unanswered questions...
