The findings, presented May 23 in advance of the annual meeting of the American Society of Clinical Oncology (ASCO) represent the most comprehensive look to date at fertility outcomes following treatment for women diagnosed with breast cancer before age 40 (Abstract 1518).
Kimia Sorouri, MD, a research fellow at the Dana-Farber Cancer Center in Boston, Massachusetts, and her colleagues, looked at data from the Young Women’s Breast Cancer study, a multicenter longitudinal cohort study, for 1213 U.S. and Canadian women (74% non-Hispanic white) who were diagnosed with stages 0-III breast cancer between 2006 and 2016. None of the included patients had metastatic disease, prior hysterectomy, or prior oophorectomy at diagnosis.
During a median 11 years of follow up, 197 of the women reported attempting pregnancy. Of these, 73% reported becoming pregnant, and 65% delivered a live infant a median 4 years after cancer diagnosis. The median age at diagnosis was 32 years, and 28% opted for egg or embryo freezing to preserve fertility. Importantly, 68% received chemotherapy, which can impair fertility, with only a small percentage undergoing ovarian suppression during chemotherapy treatment.
Key predictors of pregnancy or live birth in this study were “financial comfort,” a self-reported measure defined as having money left over to spend after bills are paid (odds ratio [OR], 2.04; 95% CI 1.01-4.12; P = .047); younger age at the time of diagnosis; and undergoing fertility preservation interventions at diagnosis (OR, 2.78; 95% CI 1.29-6.00; P = .009). Chemotherapy and other treatment factors were not seen to be associated with pregnancy or birth outcomes.
“Current research that informs our understanding of the impact of breast cancer treatment on pregnancy and live birth rates is fairly limited,” Dr. Sorouri said during an online press conference announcing the findings. Quality data on fertility outcomes has been limited to studies in certain subgroups, such as women with estrogen receptor–positive breast cancers, she noted, while other studies “have short-term follow-up and critically lack prospective assessment of attempt at conception.”
The new findings show, Dr. Sorouri said, “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. 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.”
Commenting on Dr. Sorouri and colleagues’ findings, Julie Gralow, MD, a breast cancer researcher and ASCO’s chief medical officer, stressed that, while younger age at diagnosis and financial comfort were two factors outside the scope of clinical oncology practice, “we can impact fertility preservation prior to treatment.”
She called it “critical” that every patient be informed of the impact of a breast cancer diagnosis and treatment on future fertility, and that all young patients interested in future fertility be offered fertility preservation prior to beginning treatment.
Ann Partridge, MD, of Dana-Farber, said in an interview that the findings reflected a decades’ long change in approach. “Twenty years ago when we first started this cohort, people would tell women ‘you can’t get pregnant. It’s too dangerous. You won’t be able to.’ And some indeed aren’t able to, but the majority who are attempting are succeeding, especially if they preserve their eggs or embryos. So even if chemo puts you into menopause or made you subfertile, if you’ve preserved eggs or embryos, we now can mitigate that distressing effect that many cancer patients have suffered from historically. That’s the good news here.”
Nonetheless, Dr. Partridge, an oncologist and the last author of the study, noted, the results reflected success only for women actively attempting pregnancy. “Remember, we’re not including the people who didn’t attempt. There may be some who went into menopause who never banked eggs or embryos, and may never have tried because they went to a doctor who told them they’re not fertile.” Further, she said, not all insurances cover in vitro fertilization for women who have had breast cancer.
The fact that financial comfort was correlated with reproductive success, Dr. Partridge said, speaks to broader issues about access. “It may not be all about insurers. It may be to have the ability, to have the time, the education and the wherewithal to do this right — and about being with doctors who talk about it.”
Dr. Sorouri and colleagues’ study was sponsored by the Breast Cancer Research Foundation and Susan G. Komen. Several co-authors disclosed receiving speaking and/or consulting fees from pharmaceutical companies, and one reported being an employee of GlaxoSmithKline. Dr. Sorouri reported no industry funding, while Dr. Partridge reported research funding from Novartis.