Cells are created, and die, all the time. As long as More live than die, we are good.
When it's the other way around, it's a tumor. If the die-off spreads to other areas, it is malignant.
Since doctors seem to label CANCER as a CONDITION (correct me if I'm wrong), then we know the condition doesn't have stem cells. The stem cells may belong to the dying/dead cells that the 'condition' has overtaken.
What causes the 'condition'? I.E. What causes the cells to suddenly expire ?
Even they say they don't know.