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

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. 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. 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. 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.