Funding for this research was provided by:
Natural Science Foundation of Beijing Municipality (7172168)
National Key R&D Program of China (2016YFC1302601)
Beijing Municipal Science and Technology Key Development Program (D161100000816005)
Received: 24 May 2019
Accepted: 16 September 2019
First Online: 11 October 2019
Ethics approval and consent to participate
: This study was approved by the independent ethical committee/institutional review board of Peking Union Medical College Hospital (PUMCH). We obtained permission from PUMCH to collect data from the Breast Surgery Department Database. For this type of retrospective study, formal consent was not required. The study was performed in accordance with the relevant guidelines and regulations.
: Not applicable.
: The authors declare that they have no competing interests.