Conditional survival among cancer patients in the United States

Background: Conditional survival data allows those with cancer to update their prognosis and can help to access the confidence with which one can determine that a patient is “cured” of cancer. The purpose of this study is to report 5-year relative cancer survival probabilities conditional on having already survived one or more 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: Five-year relative conditional survival tends to improve with each year already survived. Improvement is greatest for more lethal cancers (e.g., lung or pancreas) and for cases with more advanced stage at diagnosis. Five-year relative survival conditional on already having survived 5 years exceeds 90% for locally staged prostate, melanoma (whites only), breast (female only), corpus uteri, urinary bladder, Hodgkin's lymphoma, rectum, colon, ovary, pancreas. Only lung cancer does not reach 90%. For these cancer sites combined, 5-year relative survival conditional on already having survived 5 years averages about 85% for regional staged disease, 68% for distant staged disease, and 87% for unknown staged disease. Five-year relative conditional survival tends to be significantly lower among patients diagnosed at older ages, among males, among non-whites, and in those diagnosed during 1990-1995 compared with later years.

Conclusion: Conditional survival probabilities provide further useful prognostic information to cancer patients, tailored to the time already survived since diagnosis.