How bad is stage 4 cancer?

According to the Cancer Institute of New South Wales, stage 4 cancer is the most severe stage of cancer and indicates distant spread. At this stage, cancerous cells are able to travel the body via blood vessels, which enables them to spread to any body part.

The other stages of cancer are stage 0, or carcinoma in situ; stage 1, or localized tumors; stage 2, or advanced localized tumors; and stage 3, which is similar to stage 2 but with more severe involvement. Stage 4 cancer is typically treated by surgery, radiation, chemotherapy or a combination of these, according to the Cancer Institute of NSW.