I recommend to watch professor Gershom Zajicek playlists on youtube. Here are of some the ideas, presented in the playlist, as I understood them (better watch for yourself). Cancer is the by product of a virus infection. Although virus does not cause cancer, only its removal can cure it. Cancer starts by a chronic inflammation. When stem cells are hit, organism triggers a protection mechanism against Cachexia (please see: Cancer is a Triad [Tumor, Para-neoplasia, Cachexia], It is assumed that stem cells, among other tasks, also secretes a substance to sustain tissue). This is done by mobilizing a pull of stem cells to a new organ namely, tumor. In the beginning the deficiency is low and compensated by a minor tumor. Patient experiences some fatigue and otherwise feels healthy. With time the deficiency grows and tumor has to grow too and causes pain. Patient seeks for medical help and the clinical phase of the disease starts.