Prospective Data Reveal Most Young Survivors of Breast Cancer Could Successfully Give Birth

Most women who attempted to conceive following treatment for stage I to III breast cancer were able to become pregnant at least once and have a live birth with factors such as younger age at diagnosis, financial comfort, and having undergone fertility preservation associated with a higher chance of becoming pregnant, according to data presented in a press event ahead of the 2024 ASCO Annual Meeting.

Researchers analyzed data from the prospective Young Women’s Breast Cancer Study of 1213 patients aged 40 years and younger who received a diagnosis of stage 0 to stage III breast cancer between the years 2006 and 2016. Of note, patients with metastatic disease or who had their uterus or ovaries removed were not included in the study.

At a median follow-up of 11 years, 197 patients reported that they attempted pregnancy. In this group, 73% became pregnant at least once, with 90% of these patients reporting having at least 1 pregnancy that resulted in a live birth. The median time to diagnosis to the first pregnancy was 48 months and among the 197 women who reported pregnancies, the median age at their breast cancer diagnosis was 32 years.

“The current research that informs our understanding of the impact of breast cancer treatment on pregnancy and life birth rates is fairly limited,” study author Kimia Sorouri, MD, MPH, a research fellow in the Breast Oncology Program at the Dana-Farber Cancer Institute in Boston, Massachusetts, said in a presentation of the data. “This is the first prospective study with greater than 10 years of follow-up to report fertility outcomes in young breast cancer survivors account for attempting pregnancy.”

“Many young women who are diagnosed with breast cancer are interested in future fertility,” Sorouri said. “However, many cancer treatments can impair an individual’s fertility and their ability to carry a pregnancy.”

Of the 197 patients who attempted to conceive after their diagnosis, approximately half of patients (51%) reported being financially comfortable, and 72% reported never having a live birth before diagnosis. A total of 28% of patients underwent fertility preservation via cryopreservation of embryos and/or eggs. In addition, 15% of patients had a known history of infertility before receiving their breast cancer diagnosis.

Regarding disease and treatment history of those who became pregnant, the majority (76%) had estrogen receptor– and/or progesterone receptor–positive disease, followed by HER2-positive disease (25%) and triple-negative breast cancer (17%).

Sixty-eight percent of patients received chemotherapy, 57% received endocrine therapy, and 58% received radiation. Additionally, patients underwent a lumpectomy (38%), unilateral mastectomy (22%), and bilateral mastectomy (41%).

Factors Associated With Pregnancy

Data showed that factors associated with a higher chance of becoming pregnant included: being younger at the time of diagnosis; being financially comfortable, defined as still having enough money left over to “buy special things after paying bills”; and having undergone fertility preservation.

“While having undergone fertility preservation at diagnosis prior to receiving their cancer treatment was predictive of a live birth, the other patient cancer and treatment factors collected are not associated with either outcome,” Sorouri said.

The researchers also uncovered factors that did not seem to have an impact on the chance of pregnancy or birth which included:

• A history of infertility
• Having previous births
• Characteristics of breast cancer
• Type of treatment received
• BRCA germline mutation status
• Race or ethnicity

“This suggests that in this modern cohort with a heightened awareness of fertility, access to fertility preservation can help to mitigate a portion of the damage from chemotherapy and other agents,” Sorouri said. “Importantly, 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.”

Reference

Sorouri K, Zheng Y, Niman SM, et al. Fertility among young breast cancer survivors attempting pregnancy: A prospective, multicentre cohort study. J Clin Oncol. 2024;42(suppl 16):1518.