The article presents mathematical models of ovarian tumors. The models are based on a mathematical simulation of interference competition. Two types of cells are involved in the competition for nutrition: normal and tumor cells. The mathematical interpretation of models is the Cauchy problem for a system of ordinary differential equations. Based on the model, the dynamics of tumor growth is determined. A model for the distribution of conditional patients in the four stages of the disease and a model for assessing survival times in groups of conditional patients are proposed.