Ovarian stimulation is the medical treatment used to obtain the patient's own eggs in the process of in vitro fertilisation (IVF). It does not involve over-treatment of the ovary, as the same hormones that the pituitary gland produces are used to stimulate the ovary's ovulation process. Therefore, the normal sequence of ovarian stimulation is not modified.
At the beginning of the menstrual cycle, follicular recruitment takes place, a process that is not mediated by any external treatment. Once the recruitment of antral follicles has taken place, the unstimulated cycle evolves to the selection of the dominant follicle and its spontaneous rupture for the release of the mature ovum susceptible to fertilisation.
When we perform an ovarian stimulation treatment, we use the same hormones produced by the pituitary gland in the ovarian cycle to ensure that all the antral follicles recovered grow so that none are lost and we can recover all the oocytes in a cycle. We do not therefore encourage tumour proliferation in the ovary, we only prevent the follicles that do not grow from being lost. This process does not pose any "threat" to the ovary, but rather a recovery of its full potential.
To answer the question posed: there is no increased risk of cancer with ovarian stimulation treatment.