Conditional survival among cancer patients in the United States.

PURPOSE: To report 5-year relative cancer survival probabilities conditional on having already survived > or = 1 years after the initial diagnosis for 11 cancer sites, diagnosed during 1990-2001 and followed through 2006.
METHODS: Analyses are based on 1,151,496 cancer cases in population-based cancer registries in the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute.
RESULTS: The 5-year relative conditional survival probability tended to improve with each year already survived. Improvement was greatest for more lethal cancers (e.g., lung or pancreas) and for cases with a more advanced stage at diagnosis. The 5-year relative survival probability conditional on already having survived 5 years exceeded 90% for locally staged prostate cancer, melanoma (whites only), breast cancer (females only), corpus uteri cancer, urinary bladder cancer, Hodgkin's lymphoma, rectal cancer, colon cancer, ovary cancer, and pancreatic cancer. Only lung cancer did not reach 90%. For these cancer sites combined, 5-year relative survival probability conditional on already having survived 5 years averaged about 85% for regionally staged disease, 68% for distant staged disease, and 87% for unknown staged disease. The 5-year relative conditional survival probability tended to be significantly lower among patients diagnosed at older ages, among males, among nonwhites, and among those diagnosed during 1990-1995 compared with later years.
CONCLUSION: Conditional survival probability estimation provides further useful prognostic information to cancer patients, tailored to the time already survived since diagnosis.