At the recent 2025 congress of the European Society for Medical Oncology (ESMO), researchers led by Fedro A. Peccatori, MD, presented compelling new results from the POSITIVE trial — a study designed for pre-menopausal women with early hormone-receptor positive breast cancer who wish to pursue pregnancy after treatment. The findings mark a significant advance for young women with breast cancer facing the prospect of early menopause, fertility loss and a disrupted reproductive future.
What the study examined
The POSITIVE trial (ClinicalTrials.gov NCT02308085) enrolled pre-menopausal women (age ≤ 42) with hormone-receptor–positive, stage I-III breast cancer who had received standard adjuvant endocrine therapy and then paused it to attempt conception under close monitoring. ClinicalTrials.gov+2Oncology Pro+2 At ESMO 2025, Dr. Peccatori and colleagues reported updated 5-year follow-up data showing that this planned interruption of endocrine therapy is feasible and does not appear to increase the risk of breast-cancer recurrence at the time-point reported. Conference Correspondent+2ESMO Open+2
Among noteworthy results:
- Approximately 74 % of enrolled women were able to conceive either spontaneously or with assisted reproductive technology (ART). ESMO Open+1
- Hormonal markers such as anti-Müllerian hormone (AMH) and follicle-stimulating hormone (FSH) were shown to help predict fertility outcomes, illustrating that younger age and less prior chemotherapy were favourable predictors. PubMed+1
- Importantly, the recurrence rates in this cohort who paused endocrine therapy were comparable to historical controls who did not, alleviating a major concern for both clinicians and patients. Conference Correspondent+1
Why this matters, especially for young women with breast cancer
For women diagnosed with breast cancer in their reproductive years, the diagnosis often brings far more than cancer-treatment decisions—it also brings early menopause, compromised fertility, and difficult reproductive choices. The incidence of breast cancer among younger women is rising: for example, U.S. data show that in women under 45 years old the incidence increased by ~1.1 % per year from 2012 to 2022. CDC Similarly, the Breast Cancer Research Foundation reports that incidence in women under 50 rose about 1.4 % per year from 2012–2022. Breast Cancer Research Foundation
In this context, the POSITIVE trial’s findings are especially encouraging. They suggest that – under the right circumstances and with careful monitoring – young women who face breast cancer may still retain meaningful fertility and reproductive options. From the AskEllyn perspective, this shifts the narrative away from “lost opportunities” to “possible futures” for fertility, family-making and pregnancy even post-diagnosis.
Key takeaways for patients and clinicians
- Shared decision-making is critical. The choice to interrupt endocrine therapy should be made in a multidisciplinary context (oncology, fertility/gynecology, reproductive endocrinology) with a full understanding of risks and benefits.
- Pre-treatment fertility counselling remains central. Knowing one’s ovarian reserve (e.g., AMH levels), the potential impact of chemotherapy, and fertility preservation options remains foundational. The POSITIVE data confirm that such measures matter.
- Timing and monitoring matter. In POSITIVE, women paused endocrine therapy for up to two years to attempt conception and then resumed therapy—a structured design that was crucial to safety.
- Long-term data still needed. While this 5-year data is promising, continued follow-up will help further define risk over longer time-horizons, especially as endocrine therapy durations are often five years or more.
- Reproductive counselling must step up. As breast cancer treatments improve and survivorship increases, fertility and pregnancy begin to rightfully take their place as quality-of-life endpoints alongside survival. This is especially important given the rising incidence among younger women. Daily Reporter
AskEllyn’s Take: A Message of Hope for Young Women with Breast Cancer
At AskEllyn, we hear again and again from young women who feel that a breast-cancer diagnosis suddenly uproots not just their health, but their life plans—pregnancy, motherhood, fertility, and menopause. Early menopause induced by treatment can feel like an irreversible cutoff. The POSITIVE trial results offer genuine hope: for many young women, a path to pregnancy and family-making may remain open. It doesn’t erase the diagnosis or its profound impact—but it invites us to imagine a future beyond survival, a future where fertility and motherhood are still part of the conversation.
To our community of young survivors: this is a message worth sharing with your oncology and fertility teams. Share this study with your care team. Seek out the guidance of an oncology fertility specialist. Ask about the data, ask about how it may apply to your situation, ask about monitoring, timing, and safe plans. While each individual’s cancer journey is unique, the fact that this rigorous trial shows safety and possibility is a game-changer.
Further Reading from AskEllyn
We’ve written previously about these related topics:
- Photo essay portrays young women facing breast cancer (on AskEllyn)
- How one young woman diagnosed with breast cancer is using her recklessness for good (on AskEllyn)
- Hope and answers for women facing menopause after breast cancer (on AskEllyn)
We invite you to explore those posts as complementary reading, and to continue the conversation with your care team.
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