Abstract: Background and purpose: The study described 5- and 10-year observed survival and disease-free survival (DFS) of over 35 thousand breast cancer patients from a hospital-based cancer registry database, aiming to provide real world evidence of long-term survival among Chinese breast cancer patients. Methods: A total of 35 872 hospitalized breast cancer patients in Fudan University Shanghai Cancer Center (FUSCC) from Jan. 1, 2003 to Dec. 31, 2017 were included in the analysis. Medical records review, telephone visits and death registry data linkage were carried out for collecting endpoint data. The last follow-up date was Nov. 30, 2019. Kaplan-Meier method was uesd to evaluate the 1-year, 3-year, 5-year and 10-year overall survival (OS) and DFS rate for all, and data were stratified by age group, gender and calendar periods. Results: With a median follow-up time of 4.7 years, the 5-year and 10-year OS of all patients was 92.5% and 83.0%, while DFS was 86.6% and 77.0% respectively. OS and DFS among different age groups were significantly different, while no significant difference existed between females and males. The 5-year OS and DFS for patients diagnosed during the five periods of 2003-2005, 2006-2008, 2009-2011, 2012-2014, 2015-2017 were 85.8%, 92.0%, 92.1%, 92.9%, 93.8% and 70.2%, 84.7%, 86.0%, 87.8%, 90.1%, respectively. The 10-year OS for patients during 2003-2005 and 2006-2008 was 71.0% and 82.6%, while DFS was 56.0% and 75.2%, showing an improvement of 11.6% on OS and 19.2% on DFS in 2006-2008 compared with in 2003-2005, respectively. Conclusion: It is the first report on survival up to 10 years among Chinese breast cancer patients, showing that the patients have experienced significant improvement on OS and DFS during consecutive calendar periods between 2003 and 2017, which might be contributed to early diagnosis from cancer screening and novel treatments. Besides, patients younger than 35 experience poor survival and need more concern in the future.

Key words: Breast cancer, Overall survival, Disease-free survival, Hospital-based registry