  The main target of this paper is to present an efficient method to solve a
nonlinear free boundary mathematical model of prostate tumor. This model
consists of two parabolics, one elliptic and one ordinary differential
equations that are coupled together and describe the growth of a prostate
tumor. We start our discussion by using the front fixing method to fix the free
domain. Then, after employing a nonclassical finite difference and the
collocation methods on this model, their stability and convergence are proved
analytically. Finally, some numerical results are considered to show the
efficiency of the mentioned methods.
