Use of cohort analysis, complete analysis and period analysis in estimating long-term survival of breast cancer: A hospital-based report among 7 275 female patients

Objective: To estimate 5-year survival rate of female breast cancer in Fudan University Shanghai Cancer Center using cohort analysis, complete analysis and period analysis methods. Methods: Clinical information was collected for all 7 275 newly-diagnosed local female breast cancer cases in Fudan University Shanghai Cancer Center, during the period from January 1, 1997 to December 31, 2011. Follow-up survey and record linkage with the Shanghai Vital Registry were conducted to obtain information on vital status and date of death for all patients up to December 31, 2011. Cohort analysis, complete analysis and period analysis were applied respectively to estimate 5-year survival rate of breast cancer for the interested periods of 2002-2006 and 2007-2011. Results: The observed 5-year relative survival rate was 92.3% for the patients diagnosed during the period of 2002-2006, higher than 84.7% and 88.6% estimated in cohort analysis and complete analysis, respectively, but close to 90.9% calculatedin period analysis. Similar pattern was observed in cancer patients at different pathological stages, but more evident in the advanced stage groups. The 5-year relative survival rate in 2007-2011 was estimated as 93.6% in period analysis, higher than 92.3% and 92.9% estimated in cohort and complete analysis, and higher than 91.4% of the stage-adjusted 5-year relative survival in 2002-2006. Conclusion: The survival status of female breast cancer in the studied hospital has been significantly improved in recent years, which may mainly result from progress in cancer treatment for the patients with advanced stages. DOI:10.3781/j.issn.1000-7431.2014.06.012