RESUMO
OBJECTIVE: To study the fertility outcomes of women who tried to conceive after breast cancer (BC) treatment and fertility preservation. DESIGN: Retrospective observational, bicentric cohort study. SETTING: University hospital. PATIENTS: Patients with BC. INTERVENTION: All patients who had undergone fertility preservation before BC treatment between January 2013 and July 2019 were included (n = 844). The endpoint date was March 1, 2022. Patients with missing data on pregnancy attempts after a cancer diagnosis (n = 195) were excluded from the pregnancy analysis. MAIN OUTCOME MEASURES: Cumulative incidences of pregnancy and live birth (LB) were calculated. For women who became pregnant, the time to conception was calculated between the first fertility preservation consultation and the estimated day of conception. For those who did not conceive, we considered the time between the first fertility preservation consultation and the endpoint date, or the date of patient death. A Cox regression model was used to study the predictive factors for pregnancy and LB. RESULTS: Among the 649 patients with available data on pregnancy attempts after BC diagnosis, 255 (39.3% [35.5-43.2]) tried to conceive (median follow-up of 6.5 years). Overall, 135 (52.9% [46.6-59.2]) of these patients achieved a pregnancy, mainly through unassisted conception (79.3% [72.8-84.8]), and 99 reported an LB (representing 38.8% of patients who attempted conception). In our cohort, 48 months after the first fertility preservation consultation, the cumulative incidence of pregnancy was 33.1% ([27.6-37.9]). After adjustment for age, parity, type of chemotherapy administration, and endocrine therapy, only multiparity at diagnosis and absence of chemotherapy were positive predictive factors of pregnancy after cancer. Of the 793 patients who had vitrified oocytes and embryos, 68 used them (27% [21.3-32.5] of the patients who tried to conceive), resulting in 8 LBs (11.8% [5.2-21.9]). Women who used their cryopreserved oocytes and embryos were older at the first consultation of fertility preservation (hazard ratio 1.71 [1.42-2.21]), and chose more often to vitrify embryos (hazard ratio 1.76 [1.28-2.23]). CONCLUSION: Although pregnancy rates after fertility preservation for patients with BC are low, most conceptions are achieved without medical assistance. Our findings provide useful information to advise women on the different techniques of fertility preservation, their efficacy, and safety, as well as the relatively high chances of unassisted conception.
RESUMO
OBJECTIVE: To study whether fertility preservation strategies using ovarian stimulation or without using it impact long-term disease-free survival of patients with breast cancer. DESIGN: Retrospective bicentric cohort study. SETTING: Two university hospitals. PATIENT(S): In this study, 740 women with breast cancer, aged 18-43 years, who received primary fertility preservation between 2013 and 2019 after a diagnosis of localized breast cancer were included. INTERVENTION(S): Overall, 328 patients underwent at least 1 ovarian stimulation cycle (STIM group) and 412 had a technique without hormonal administration (no STIM group). MAIN OUTCOME MEASURE(S): Disease-free survival and overall survival up to May 2021 were compared between the 2 groups by log-rank test. Cox proportional-hazard regression model was used for multivariable analyses. RESULT(S): Out of the 740 women who underwent fertility preservation, follow-up data were available for 269 women in the STIM group (82%) and 330 (80%) in the no STIM group. Kaplan-Meier estimates of disease-free survival at 4 years were 87.9% (82.8%-92.2%) and 83.1% (78.4%-87.3%) in the STIM and no STIM groups, respectively. After adjustment on prognostic parameters, no significant difference in breast cancer recurrence rate was observed between the STIM and no STIM groups (hazard ratios, 0.83 [0.64-1.08]). Kaplan-Meier estimate of overall survival at 4 years was 97.6% (95.3%-99.2%) and 93.6% (90.9%-95.9%) in the STIM and no STIM groups, respectively. Overall survival was higher in the STIM group than no STIM group (log-rank test). After adjustment on prognostic parameters, the risk of death remained significantly lower in the STIM group (Hazard Ratio, 0.55 [0.35-0.85]). CONCLUSION(S): In our cohort, STIM for fertility preservation in breast cancer did not significantly impact disease-free survival but was associated with higher overall survival. The disease-free survival and overall survival of young patients with breast cancer were not impacted by fertility preservation techniques irrespective of the timing of chemotherapy (neoadjuvant or adjuvant) and the use of ovarian stimulation. Nevertheless, because death and recurrence were rare events, these results should be taken with caution.