The impact of breast cancer on fertility is a growing concern as the average age of breast cancer diagnosis continues to decrease. Until recently, we didn't know whether it was safe for patients with estrogen receptor positive tumors to stop endocrine therapy and get pregnant. I recently saw a 37 year old woman who had been diagnosed with ER/PR-positive breast cancer 4 years ago. She presented with node negative breast cancer and a tumor size of 1.8 cm (T1 N0 M0), ER/PR-positive, HER2-negative, with an Oncotype Recurrence Score of 14. The patient proceeded with lumpectomy and radiation therapy, and has been on tamoxifen for 3.5 years. She asked me if it would be safe to stop her endocrine therapy and become pregnant.
Let's discuss the POSITIVE clinical trial, a groundbreaking study that has opened new doors for women balancing the critical decision between cancer treatment and family planning. The trial has introduced a paradigm shift: the feasibility of pausing cancer treatment to pursue pregnancy without adversely affecting cancer outcomes.
At the 2023 San Antonio Breast Cancer Symposium, we received an encouraging update on this study. It was revealed that patients interrupting their breast cancer treatments for pregnancy could also engage in assisted reproductive technologies (ART), such as ovarian stimulation for in vitro fertilization (IVF). Remarkably, this approach does not increase the risk of cancer recurrence. Additionally, the trial supported safe fertility preservation methods, like egg cryopreservation prior to beginning cancer treatment.
Dr. Hatem A. Azim Jr., MD, PhD, an adjunct professor at the School of Medicine and Breast Cancer Center at Tecnológico de Monterrey in Mexico, presented these findings. He stressed the importance of these results, noting that they "confirm the effectiveness and short-term safety of various fertility preservation and ART options." This is a significant advancement for fertility guidance in young breast cancer patients.
One of the longstanding concerns in the medical community has been the safety of fertility preservation and ART, especially in hormone receptor (HR)-positive breast cancers. These cancers, commonly treated with hormone therapies, have historically prompted recommendations against pursuing pregnancy during treatment.
The POSITIVE trial, which included 497 women with HR-positive breast cancer, examined the effects of pausing hormone therapy to allow for pregnancy. With 368 participants successfully conceiving after stopping endocrine therapy, the trial demonstrated outcomes similar to those who continued treatment, suggesting that a two-year treatment break is a viable option for women desiring to conceive.
However, the safety of using fertility preservation or ART during this treatment hiatus remained a question. A secondary analysis of the POSITIVE trial focused on 179 patients who had used embryo or oocyte cryopreservation before the trial, and 215 attempted pregnancy through ART during the treatment break. The results were promising: ovarian stimulation for IVF did not increase the short-term risk of cancer recurrence. Additionally, the pregnancy success rate through ART was impressively high at 82.4%.
These findings from the POSITIVE trial are pivotal. They suggest that HR-positive breast cancer patients can safely pause their treatment, either naturally or through fertility preservation and ART, without increasing their short-term risk of disease recurrence. This trial not only offers new hope for those facing breast cancer but also reshapes our approach to patient care, allowing us to support our patients' desires for motherhood without compromising their cancer treatment outcomes.
As we continue to navigate the complexities of cancer treatment and fertility, these insights are invaluable, enhancing our ability to provide holistic, patient-centered care. Stay tuned for more updates as we further explore and understand the implications of this groundbreaking research.