In next several decades, medical costs are going to increase significantly with the obvious increase of ageing population. The development trend of medical cost was predicted on the basis of over-cost growth model. The over-cost growth and the influencing factors of population and economics were first used to construct the time series model, then Monte Carlo approach was used in random simulation and finally the prediction result of medical cost in China was received.

With the increasing incidence of breast cancer, the relationship between tumor and immune function has attracted more and more attention. This article reviews the relationship between breast cancer and T lymphocyte subsets, in order to explore the changes of immune function before and after operation in breast cancer patients, so as to select appropriate surgical methods, radiotherapy, chemotherapy and immunotherapy for the patients.