Background: Cancer is a genetic disease caused by the accumulation of gene
mutations. It is important to derive the number of driver mutations that are needed for the
development of human breast cancer, which may provide insights into the tumor diagnosis and
Objective: This work is designed to investigate whether there is any difference for the mutation
mechanism of breast cancer between the patients in the USA and those in China. We study the
mechanisms of breast cancer development in China, and then compare these mechanisms with
those in the USA.
Methods: This work designed a multistage model including both gene mutation and clonal
expansion of intermediate cells to fit the dataset of breast cancer in China from 2004 to 2009.
Results: Our simulation results show that the maximum number of driver mutations for breast
epithelium stem cells of females in China is 13 which is less than the 14 driver mutations of
females in the USA. In addition, the two-hit model is the optimal one for the tumorigenesis of
females in China, which is also different from the three-hit model that was predicted as the optimal
model for the tumorigenesis of females in the USA.
Conclusion: The differences of the mutation mechanisms between China and the USA reflect a
variety of lifestyle, genetic influences, environmental exposure, and the availability of mammography