In a Swedish nationwide cohort study reported in JAMA Oncology, Marklund et al found that women who had undergone fertility preservation had a higher live birth rate, were more likely to use assisted reproductive technology, and had better overall survival after breast cancer than women who had not undergone fertility preservation.
The study involved data from women with breast cancer who received fertility preservation at regional programs between 1994 and 2017 (n = 425). Comparators with breast cancer but without a history of fertility preservation (n = 850) sampled from regional breast cancer registers were matched for age, calendar period of diagnosis, and county. Data on live births, assisted reproductive technology use, and mortality were obtained from population-based registers, with analyses adjusted for time since diagnosis, age, country of birth, education, parity at diagnosis, calendar period, tumor size, lymph node metastases, estrogen receptor status, and chemotherapy.
“In this cohort study of Swedish women after a breast cancer diagnosis, successful pregnancy after breast cancer was possible both in women with and without fertility preservation at the time of diagnosis, but a significantly higher likelihood of post–breast cancer live births and assisted reproductive technology treatments was observed in women who underwent fertility preservation, without any negative association with all-cause survival.”— Marklund et al
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Women who had undergone fertility preservation vs those who had not had lower parity (nulliparity in 71.1% vs 20.1%), were younger (mean age = 32.1 vs 33.3 years), were more likely to have estrogen receptor–positive tumors (68.0% vs 60.6%), and were more often scheduled for chemotherapy (93.9% vs 87.7%).
After a mean follow-up of 4.6 vs 4.8 years, 97 women in the fertility preservation group (22.8%) vs 74 (8.7%) in the non–fertility preservation group had at least one live birth after breast cancer (adjusted hazard ratio [HR] = 2.3, 95% confidence interval [CI] = 1.6–3.3). The 5-year and 10-year cumulative incidence of post–breast cancer live births was 19.4% vs 8.6% and 40.7% vs 15.8%.
The 5-year cumulative incidence of live birth was 19.0% vs 12.7% among women who were nulliparous at the time of breast cancer diagnosis, and 20.2% vs 7.5% among those who had given birth to at least one child prior to diagnosis.
At least one post–breast cancer assisted reproductive technology treatment was received by 48 women (11.3%) in the fertility preservation group vs 10 (1.2%) in the non–fertility preservation group (adjusted HR = 4.8, 95% CI = 2.2–10.7).
After a mean follow-up of 5.8 vs 5.2 years, 27 women (6.4%) in the fertility preservation group and 110 (12.9%) in the non–fertility preservation group had died (adjusted HR = 0.4, 95% CI = 0.3–0.7), with 5- and 10-year cumulative all-cause mortality of 5.3% vs 11.1% and 13.8% vs 23.2%.
The investigators concluded, “In this cohort study of Swedish women after a breast cancer diagnosis, successful pregnancy after breast cancer was possible both in women with and without fertility preservation at the time of diagnosis, but a significantly higher likelihood of post–breast cancer live births and assisted reproductive technology treatments was observed in women who underwent fertility preservation, without any negative association with all-cause survival. This information is valuable for health-care clinicians responsible for oncologic treatment and reproductive counseling of women diagnosed with breast cancer at reproductive age.”
Kenny A. Rodriguez-Wallberg, MD, PhD, of the Department of Oncology-Pathology, Karolinska Institutet, and Department of Reproductive Medicine, Karolinska University Hospital, is the corresponding author for the JAMA Oncology article.
Disclosure: The study was supported by Cancerfonden, Radiumhemmets Forskningsfonder, Stockholm County Council, and Karolinska Institute. For full disclosures of the study authors, visit jamanetwork.com.