Our aim is to develop an optical biopsy method for an early detection of cancer in hollow organs. A model accounting for light scattering in a multistratified, heterogeneous and scattering system, with a geometry close to biological tissues is presented. It is based on the resolution of the Vector Radiative Transfer Equation by the discrete ordinate method. It calculates the spatial distribution and the spectral variations of the scattered light according to various states of polarization. It has been validated on phantoms samples. A simulation of the cancerization process inside an epithelium, by using this model, shows that it should be possible to distinguish a healthy tissue from a dysplasic one.