Avoidance of premature death: a new definition for the proportion cured.
For many cancers, five-year survival is used as a synonym for cure. For some sites, such as breast, this is inappropriate since there is still considerable excess mortality 5-15 years following diagnosis. We propose using the probability of not dying prematurely as a surrogate for the probability of being cured. This is estimated without the need for information on the cause of death by comparing all-cause-mortality rates in patients with cancer to those in the general population. We also consider the probability of 'cure' in those who have survived a certain number of years since diagnosis. These quantities are estimated for various cancer sites using SEER data. The proportion not dying prematurely varies considerably for common cancers from 12% for lung cancer to 84% for prostate cancer. In women, the percentage 'cured' for colon and breast cancer are very similar at 56% and 58% respectively, but in those who survive 5 years, they are quite different--91% and 78% respectively. The proposed statistic is useful. For diseases in which excess mortality is primarily within five years of diagnosis, it agrees well with 5-year relative survival. Interpretation of differences between countries or over time is complicated and requires consideration of incidence and mortality data.
Sasieni
P D
PD
Cancer Research UK Department of Epidemiology, Mathematics and Statistics, Wolfson Institute of Preventive Medicine, London. peter.sasieni@cancer.org.uk
Adams
J
J
Cuzick
J
J
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000401:mortality*; D011336:Probability; D016016:Proportional Hazards Models; D018426:SEER Program; D016019:Survival Analysis; D014481:United States / Q000453:epidemiology