Secondary Bone Cancer Fatality Rate Secondary bone cancer known as metastasis can be fatal. These are cancers that start elsewhere and go into the bone. The secondary bone cancers can lead to death, not because they are in bone, but because it’s a cancer that started off somewhere else, and it can spread many other places. Once a patient is diagnosed with the metastasis, we know that their cancer has already proven that it can spread, and if it’s already in one bone, the odds are it’s either in other bones or it’s in other organs. And so once its spread, not everyone dies from that, but it is much harder to treat once it’s already spread.