Cancer patient survival in Sweden at the beginning of the third millennium--predictions using period analysis.

Estimates of cancer patient survival made using traditional, cohort-based, methods can be heavily influenced by the survival experience of patients diagnosed many years in the past and may not be particularly relevant to recently diagnosed patients. Period-based survival analysis has been shown to provide better predictions of survival for recently diagnosed patients and earlier detection of temporal trends in patient survival than cohort analysis. We aim to provide predictions of the long-term survival of recently diagnosed cancer patients using period analysis. The period estimates are compared with the latest available cohort-based estimates. Our results, based on period analysis for the years 2000-2002, suggest an improvement in survival for many forms of cancer during recent years. For all sites combined the 5-, 10-, 15-, and 20-year relative survival ratios were 62%, 53%, 48%, and 47% for males and 67%, 62%, 60%, and 59%, for females. These estimates were 3-14% units higher than those obtained using the latest available cohorts with the respective lengths of follow-up. The interval-specific relative survival stabilised for males at 97% after 8 years of follow-up and for females at 98% after 7 years for both period and cohort analyses.