The cornerstone of treatment for the great majority of cancers is the surgical removal of the primary tumor. The rationale for this approach is straightforward: if you can get rid of the cancer by simply removing it from the body, then a cure can likely be achieved. Unfortunately, this approach does not take into account that after surgery the cancer will frequently metastasize (spread to different organs). Quite often the metastatic recurrence is far more serious than the original tumor. In fact, for many cancers it is the metastatic recurrence—and not the primary tumor—that ultimately proves to be fatal.