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Most Women Can Have Successful Pregnancies After Breast Cancer Treatment

— Fertility preservation before treatment strongly predictive of live births, study shows

MedpageToday

CHICAGO -- The vast majority of young breast cancer survivors who attempted pregnancy after treatment were able to become pregnant and have a live birth, according to a prospective cohort study.

With more than 10 years of follow-up, 73% of women who attempted pregnancy after treatment for stage 0 to III breast cancer became pregnant at least once, with 90% having at least one live birth, reported Kimia Sorouri, MD, MPH, of the Dana-Farber Cancer Institute in Boston.

The median time from breast cancer diagnosis to first pregnancy was 48 months, and older age at diagnosis was associated with lower odds of pregnancy (adjusted OR 0.82 per year increase, 95% CI 0.74-0.90, P<0.0001) and live birth (aOR 0.82 per year increase, 95% CI 0.76-0.90, P<0.0001).

On the other hand, financial comfort at time of diagnosis was predictive of pregnancy (aOR 2.04, 95% CI 1.01-4.12, P=0.047), and fertility preservation was predictive of live birth (aOR 2.78, 95% CI 1.29-6.00, P=0.009).

"Of note, fertility preservation prior to cancer treatment consisting of freezing eggs or embryos was predictive of live births," Sorouri said during a press briefing in advance of the American Society of Clinical Oncology (ASCO) annual meeting.

"This suggests that in this modern cohort, with a heightened awareness of fertility, access to fertility preservation can help to mitigate the damage from chemotherapy and other agents," she added. "This highlights the need for increased accessibility of fertility preservation services for women newly diagnosed with breast cancer who are interested in a future pregnancy."

Julie Gralow, MD, chief medical officer and executive vice president of ASCO, who moderated the press briefing, noted that while oncologists "can't do a lot to impact [younger age and financial comfort at diagnosis] ... we can impact fertility preservation prior to treatment."

"It is really critical that every patient be informed of the impact of a breast cancer diagnosis and treatment on future fertility," she said. "And that we actually offer all young patients ... fertility preservation prior to beginning their treatment, and that we should have equitable access for all."

"It is impressive that this is the first study with long-term follow-up to look at fertility in pregnancy in all subtypes of breast cancer," Gralow added. "It's also impressive that 68% of the patients in this study did receive chemotherapy, which is known to reduce future fertility."

"The conclusion is that pregnancy after a diagnosis of breast cancer is indeed possible for the majority who desire pregnancy, and it is safe," she said.

In explaining the rationale behind the study, Sorouri suggested that current research on the impact of breast cancer treatment on fertility and live birth is somewhat limited. For example, she pointed out that some studies, such as the POSITIVE study, only included select subgroups.

POSITIVE "provided excellent data on fertility outcomes, but only for women with estrogen receptor-positive breast cancer," she said. "Other studies have short-term follow-up and -- critically -- lack prospective assessment of attempt at conception, thus the results don't truly reflect who is trying to get pregnant."

This analysis used data from the Young Women's Breast Cancer Study, a prospective cohort study of women ages 40 and younger with newly diagnosed breast cancer who were enrolled across 13 sites in the U.S. and Canada from 2006 to 2016.

Of the 1,213 eligible participants, 197 reported an attempt to get pregnant over a median follow-up of 11 years.

Among those 197 women, median age at diagnosis was 32, 74% were white, 41% had stage I disease, 35% had stage II, 10% had stage III, and 14% had stage 0. About two-thirds (68%) received chemotherapy, 57% received endocrine therapy within 1 year, and 13% were BRCA1/2 carriers.

About half (51%) of patients reported financial comfort at baseline, 28% had undergone fertility preservation consisting of egg/embryo freezing at diagnosis, and 15% reported a history of infertility before breast cancer diagnosis.

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    Mike Bassett is a staff writer focusing on oncology and hematology. He is based in Massachusetts.

Disclosures

The study was funded by the Breast Cancer Research Foundation and Susan G. Komen.

Sorouri reported no disclosures.

Co-authors reported relationships with Alston & Bird, AstraZeneca, Blue Note Therapeutics, Daiichi Sankyo, Elsevier, Exact Sciences, Gilead Sciences, GSK, Hall Matson, Included Health, Ipsen, Knight Therapeutics, Libbs, Lilly, M. Dalton Esq. and Associates, Medtronic, Menarini, Morrison, MSD, Novartis, Olema Oncology, Perla Therapeutics, Pfizer, Pierre Fabre, Roche, Rubedo Life Sciences, Seagen, Sandoz, Springer Nature, Takeda, and UpToDate.

Primary Source

American Society of Clinical Oncology

Sorouri K, et al "Fertility among young breast cancer survivors attempting pregnancy: a prospective multicentre cohort study" ASCO 2024; Abstract 1518.