A comparison of Chinese multicenter breast cancer database and SEER database

There are different characteristics of BC in developing countries and developed countries. We intended to study the factors which influence the survival and prognosis of BC between southern China and the United States. (a) To study the two groups BC patients in southern China from 2001 to 2016 and SEER database from 1975 to 2016. (b) To register, collect and analyze the clinicopathological features and treatment information. Our study found that there are significant differences in tumor size, positive lymph node status and KI-67 between southern China and SEER cohort (P < 0.000). The positive lymph node status may be one of the causes of difference of morbidity and mortality of BC patients in China. Furthermore, the differences in treatment methods may also account for the differences between China and seer databases.