Estimating Relative Survival of Breast Cancer Patients Referring to Imam Khomeini Cancer Institute during 1990-95

Introduction: In comparison with observed and cause-specific survival relative survival as an estimate of net survival has become a more preferred measure for the analysis of patients survival based on data from population-based-cancer registries. A major advantage of this measure is that information on the cause of death is not required thereby circumventing problems with the inaccuracy incorrectness and non-availability of death certificates and problems due to complicated cures. This research is carried out to estimate and investigate the net survival of breast cancer patients. Methods: In order to estimate relative survival we used Finnish annual probabilities of death as a standard source to estimate expected survival in this study. Data consist of 662 breast cancer patients diagnosed at the Cancer Institute of Imam Khomeini Hospital during 1990-95 and followed up to the end of 2000. Data were analyzed using SAS software version 9.1. Results: The results showed that the three-year relative survival for 3 age groups of 15-44 45-59 and 60-74 were 85 90 and 80% respectively whereas it was low for the age group of 75+ (67%). Following up the age group of 45-59 for two consequent years the estimate of relative survival ratio was obtained approximately one. For some intervals the follow-up estimate of relative survival was greater than one. Conclusion: Based on the results survival following diagnosis of cancer has decreased with the increasing of age groups. It is also seen that with the increasing years of follow-up survival following diagnosis of cancer has first decreased and then a little increased. The decreasing rate for age group of 75+ is noticeable. The statistical cure point for the age group of 45-59 is acceptable but for the age groups of 45-59 and 60-74 the quality of following up is low in some follow-up intervals. --------------------------------------------------------------------------------