medwireNews: Among breast cancer survivors carrying BRCA1/2 variants, the use of assisted reproductive technology (ART) to conceive does not appear to worsen disease-free survival (DFS) or pregnancy outcomes, suggests an international cohort study.
“[O]ur results add novel and specific information for the oncofertility counselling of young BRCA1/2 carriers with a pregnancy after breast cancer,” write Matteo Lambertini (University of Genova-IRCCS Ospedale Policlinico San Martino, Italy) and co-workers in the European Journal of Cancer.
The researchers explain that “[o]ver the past years, increasing evidence has shown the safety of [ART] performed before or after anticancer treatments in patients with a history of breast cancer,” but the evidence for those harboring germline BRCA1/2 pathogenic variants “is very limited.”
To address this knowledge gap, they analyzed data for 543 BRCA1/2 carriers who became pregnant after a breast cancer diagnosis at or before the age of 40 years between 2000 and 2020. Of these, 107 required ART to conceive, while the remaining 436 became pregnant spontaneously.
The most used ART technique was controlled ovarian stimulation (COS) for oocyte/embryo cryopreservation at diagnosis, in 45.5% of women, followed by COS or ovulation induction after anticancer treatments and oocyte donation, in 33.3% and 21.2%, respectively.
Women in the ART group were significantly older at cancer diagnosis and at conception than those in the no ART group, at a median of 32.0 versus 30.0 years and 37.1 versus 34.3 years, respectively. They were also significantly more likely to be childless at diagnosis, at 71.8% versus 51.5%, and to have hormone receptor-positive disease, at 43.4% versus 30.8%.
At a median follow-up of 5.2 years after conception, there were 13 DFS events among women who used ART and 118 among those who did not, equating to rates per 100 person–years of 3.45 and 5.35, respectively.
After adjusting for risk-reducing mastectomy and salpingo-oophorectomy as well as for the propensity of using ART, there was no significant difference in DFS between the groups, with a nonsignificant hazard ratio for a DFS event or death of 0.72.
There were also no statistically significant differences between women who did versus did not use ART with respect to pregnancy complications.
However, the incidence of miscarriages was numerically higher in the ART than no ART group, at respective rates of 11.3% and 8.8%, which the researchers think “may reflect the older median age at the time of pregnancy in the ART group.”
By contrast, there were fewer induced abortions, at 0.9% and 8.3%, respectively.
“Knowing the suboptimal use of contraception in young women with breast cancer, patients who conceived spontaneously might have experienced an unintended pregnancy and then opted for an induced abortion,” comment Lambertini and colleagues.
They conclude that “[f]uture prospective studies are needed to confirm our results.”
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Eur J Cancer 2025; doi:10.1016/j.ejca.2025.115434
