Cross-correlation enhanced stability in a tumor cell growth model with immune surveillance driven by cross-correlated noises.

The transient properties of a tumor cell growth model with immune surveillance driven by cross-correlated multiplicative and additive noises are investigated. The explicit expression of extinction rate from the state of a stable tumor to the state of extinction is obtained. Based on the numerical computations, we find the following: (i) the intensity of multiplicative noise D and the intensity of additive noise a enhance the extinction rate for the case of l [?] 0 (i.e. l denotes cross-correlation intensity between two noises), but for the case of l > 0, a critical noise intensity D or a exists at which the extinction rate is the smallest; D and a at first weaken the extinction rate and then enhance it. (ii) The immune rate b and the cross-correlation intensity l play opposite roles on the extinction rate, i.e. b enhances the extinction rate of the tumor cell, while l weakens the extinction rate of the tumor cell. Namely, the immune rate can enhance the extinction of the tumor cell and the cross-correlation between two noises can enhance stability of the cancer state. [ABSTRACT FROM AUTHOR]