relative survival rate
(REH-luh-tiv ser-VY-vul …)
A way of
          comparing the survival of people who have a specific
          disease with those who don’t, over a certain period of
          time. This is usually five years from the date of diagnosis
          or the start of treatment for those with the disease. It is
          calculated by dividing the percentage of patients with the
          disease who are still alive at the end of the period of
          time by the percentage of people in the general population
          of the same sex and age who are alive at the end of the
          same time period. The relative survival rate shows whether
          the disease shortens life.