Quantitative microscopy by image analysis allows not only to measure various parameters on each cell but also to consider the global population as a whole. In the hypothesis that cell position is reflecting the relational and dynamical structure of the system, spatial arrangement analysis may help to show up intercellular communication (interactions and control systems via contact or diffusible factors). We describe a topographical analysis method used to study these neighbour relationships, and thus the sociological behaviour of the cells. It is applied to the study of the effect of estrogenic and antiestrogenic treatments on a breast cancer cell line (MCF-7). It shows up that estrogens increase proliferation and induce an unusual topographical behaviour, notably in cell cycle phases: cells in S phases are very randomly distributed. It points out the role of estrogens on the cells neighbour relationships inducing the way to a permissive proliferation context. This effect is reversed by antiestrogenic treatment after a few days. Antiestrogenic treatment alone increases the proliferation constraint.