[Live birth rates after breast cancer among women who desired a child]

In France, the breast cancer is the most common cancer among women under the age of 40. From 38 to 70% of women have not fulfilled their parental plans at the time of diagnosis. The gonadotoxicity of the treatments and the follicular physiological decline linked to age can become an obstacle to this project.

Among the patients, 386 were treated for breast cancer at the Centre Georges-François-Leclerc in Dijon between January 2011 and December 2018 were identified. 192 patients aged under 39 met the inclusion criteria. We excluded metastatic cancers, cancer in situ and pregnant patients at diagnosis. A total of 124 patients agreed to participate in the study. The included patients filled out a self-questionnaire. Data were collected from the patient's electronic medical. The primary endpoint of this study was the live birth rate.

Among women who desired a child after breast cancer, the overall rate of live births was 36.2 % (21/58). Most achieved pregnancies were spontaneous (90.5 %). No factor was significantly associated with the absence of obtaining birth. Fertility was preserved by oocyte cryopreservation in 13.8 % of patients (17/124). The median time to conception in patients who received chemotherapy was 8 months [1.0-60.0] vs 2 months [1.0-7.0] in women who did not receive chemotherapy.

The non-negligible proportion of live births following spontaneous pregnancy after breast cancer allows us to be reassuring for patients. However, the emergence of new chemotherapy protocols whose consequences on long-term gonadotoxicity are still not well known requires further studies and prompts the promotion of fertility preservation as a precautionary measure.