Stage 4 cancer means there is a distant spread of the cancer, states Cancer Institute NSW. This progression is also called metastasis. Due to metastasis, stage 4 cancer is usually not cured with surgery or radiotherapy, states Oasis of Hope.
The stages of cancer span from zero to four, with four being the most severe, explains Cancer Institute NSW. Stage 0 cancer is called in situ cancer, or cancer that has not yet spread. Stage 1 is localized cancer, or cancer that has begun to spread to the surrounding cells. Stages 2 and 3 are characterized by the regional spread of cancer. Cancer invades the lymph nodes during these stages.