Five-year
relative survival rates are more commonly cited in
cancer statistics. Five-year absolute survival rates may sometimes also be cited. • Five-year
absolute survival rates describe the percentage of patients alive five years after the disease is diagnosed. • Five-year
relative survival rates describe the percentage of patients with a disease alive five years after the disease is diagnosed, divided by the percentage of the general population of corresponding sex and age alive after five years. Typically, cancer five-year relative survival rates are well below 100%, reflecting excess mortality among cancer patients compared to the general population. In contrast to five-year absolute survival rates, five-year relative survival rates may also equal or even exceed 100% if cancer patients have the same or even higher survival rates than the general population. The pattern may occur if cancer patients can generally be cured, or patients diagnosed with cancer have greater socioeconomic wealth or access to medical care than the general population. :The fact that relative survival rates above 100% were estimated for some groups of patients appears
counterintuitive on first view. It is unlikely that occurrence of
prostate cancer would increase chances of survival, compared to the general population. A more plausible explanation is that the pattern reflects a
selection effect of
PSA screening, as
screening tests tend to be used less often by
socially disadvantaged population groups, who, in general, also have higher mortality. ==Uses==