For example, if the 5-year relative survival rate for a specific stage of bile duct cancer (cholangiocarcinoma) is 30%, it means that people who have that cancer are, on average, about 30% as likely as people who don’t have that cancer to live for at least 5 years after being diagnosed.
https://www.cancer.org/cancer/bile-duct-cancer/detection-diagnosis-staging/survival-by-stage.html