Thanks to BCRF-supported research, some younger patients have reassurance that they can pause endocrine therapy to get pregnant
A breast cancer diagnosis is life-altering for women at any age. But for younger women, questions about future fertility swirl right alongside those about prognosis and breast cancer treatment. Should I freeze my eggs? Will treatments cause early menopause? Will I need to undergo IVF or use a surrogate?
Fertility was top of mind for Alexandria Whitaker Cheadle seven years ago when she was diagnosed with stage 1 triple-positive breast cancer at just 24 years old.
“I’m so thankful to have an oncologist who enthusiastically listened and supported me from day one of my diagnosis when it came to preserving my fertility,” she said.
Breast cancer treatments, while lifesaving, can impact a woman’s ability to conceive in several ways. Some, like chemotherapy and certain endocrine therapies (also known as hormone therapies) that reduce a woman’s risk of recurrence, can cause temporary or permanent menopause. Others, like radiation, don’t impact fertility at all.
Because Alex’s tumor was triple-positive—meaning her tumor had both hormone receptors and HER2 receptors—she received endocrine therapy (an aromatase inhibitor and ovarian suppression), chemotherapy, and HER2-targeted treatments. After a year of active treatment, she continued taking the aromatase inhibitor daily.
Around five years into endocrine therapy, Alex’s oncologist started a conversation about pausing to start a family.
“He knew how important children were to me and my husband,” she said. “I was really nervous, but he pointed me to the early results of the POSITIVE trial, which was still underway at the time, and other research that helped ease my mind and feel good about stopping endocrine therapy to get pregnant.”
After deciding to pause and try to conceive, Alex and her husband were overjoyed to learn she was pregnant, and in January of this year, she gave birth to a healthy baby boy named Beckham.
Results from the first-of-its-kind POSITIVE trial have been game-changing for younger women diagnosed with hormone receptor–positive breast cancer. Led by BCRF investigator Dr. Ann Partridge and supported by BCRF, POSITIVE sought to empower these patients with data
“The POSITIVE trial addresses a very important clinical conundrum facing our youngest patients with breast cancer: how to get the best possible breast cancer treatment in the setting of hormone-sensitive breast cancer, which often requires years of endocrine therapy, and at the same time pursue the great desire among many young women to have a baby in the not too distant future,” Dr. Partridge said. “POSITIVE is the first study to tackle this question prospectively among women interested in temporarily pausing their endocrine therapy for pregnancy.”
After sharing initial findings at the 2022 San Antionio Breast Cancer Symposium, Partridge and her collaborators published results in the prestigious New England Journal of Medicine showing that a temporary interruption of endocrine therapy to get pregnant did not increase short-term breast cancer outcomes, such as recurrence.
Partridge and her team enrolled 516 women who were diagnosed with early-stage breast cancer and who had received endocrine therapy for 18 to 30 months. Seventy-four percent of the women in the trial successfully got pregnant and a little more than 63 percent gave birth. The study noted that a total of 365 babies were born as a result.
“Fortunately, the study showed that this approach appears safe at least in the short term, and we are awaiting long-term data,” Dr. Partridge said. “Further, most women in POSITIVE [73.3 percent] did indeed get back on their endocrine therapy, which was something that we were concerned about.”
More recently, fellow BCRF investigator Dr. Allison Kurian and team published results from another BCRF-supported study that looked at endocrine therapy resumption in women who pause endocrine therapy using real-world data. Investigators found that only about a third of women in the study resumed this treatment, which can cause unpleasant side effects like joint pain and hot flashes.
“This study shows in large part the problem that we were trying to solve with the POSITIVE trial, which is that some women come off endocrine therapy for pregnancy and don’t go back on because they didn’t have any kind of roadmap or prospective data to support that approach,” Dr. Partridge said. “Now that the data are available, I’m hoping that more women will use the POSITIVE approach and get back on endocrine therapy. And we doctors need to impress upon patients who take a pause that the safety of doing this relies on getting back on it.”
Melissa Cáceres Compernolle was diagnosed with stage 1, estrogen receptor–positive breast cancer soon after learning that she carried a PALB2 mutation linked to breast cancer. She underwent a lumpectomy and radiation after learning that she could safely skip chemotherapy—knowledge that helped her make fertility decisions.
“When it turned out my Oncotype score was low enough to forego chemo, we decided we could try getting pregnant without freezing my eggs or trying IVF. A fertility counselor made it clear that it would be OK for me to pursue pregnancy on my own, since the radiation I was getting on my right breast was targeted to that one area,” she said.
But, Melissa said, learning that the endocrine therapy she would go on to reduce her risk of recurrence could impact her family planning was a tough pill to swallow.
“Having kids was always part of our plan even before I got diagnosed,” she said. “It was hard hearing from my medical oncologist that being on tamoxifen would, in many ways, put rules or guidelines on what we thought would be a flexible timeline for starting our family. But we were told by my oncology team that the research showed it would be safe for me to be on tamoxifen for two years straight and then take a break to try to get pregnant. And that’s what we did.”
Melissa paused tamoxifen on the same day that she had started it two years prior and waited her doctor’s recommended three months before trying to conceive.
“Having cancer felt like such an unlucky draw,” she said. “Finding out in early September that same year that I was pregnant was such an emotional moment. We felt fortunate on so many levels. Our baby girl is due this month.”
Melissa said that pausing endocrine therapy was emotionally complicated, but she welcomed a temporary reprieve from its side effects.
“I was terrified of what it would mean for my recurrence risk. But I trusted the science backing the safety of the break enough that it helped keep my fear in check,” she said. “It was tough being in my early thirties, managing hot flashes and all the things that come with being in medically induced menopause. But what I felt would be even harder than all of that combined was the possibility of getting diagnosed with cancer again. I’m still thankful that there is a treatment available that’ll help lower my chances. And even more thankful that there’s a safe way to grow my family as I navigate my tamoxifen timeline.”
With incidence rates rising among younger women, research to address the unique needs of younger breast cancer thrivers is more critical than ever. That’s why BCRF supports studies like the POSITIVE trial and ongoing work to reduce endocrine therapy side effects for all thrivers.
“BCRF supports studies that not only aim to improve treatments for breast cancer but also difficult-to-fund studies to help patients to not only survive but to thrive after breast cancer,” Dr. Partridge said. “POSITIVE is a great example of that, and the support of BCRF was critical.”
