How Does Cancer Treatments Affect Menopause and Fertility?

Chemotherapy can trigger early menopause, while strategies and new data on pausing therapy may help women protect fertility and plan pregnancy.

Chemotherapy is the treatment most likely to cause early menopause, especially for women over 40, said Dr. Elizabeth Sakach, breast medical oncologist at Winship Cancer Institute of Emory University. Endocrine therapy may not trigger menopause itself but often causes symptoms like hot flashes, sleep problems, weight gain and sexual dysfunction.

Strategies such as egg preservation or ovarian suppression can help protect fertility, though results vary. Sakach highlighted new data showing some patients can safely pause endocrine therapy to conceive without raising recurrence risk. She also noted treatment-induced menopause raises long-term concerns for bone and heart health, underscoring the need for survivorship care.

CURE: How do different cancer treatments, such as chemotherapy, radiation or hormone therapy impact ovarian function and potentially trigger early menopause?

Sakach: Of those therapies, chemotherapy has the most significant impact on ovarian function and can cause early menopause in many women, especially over the age of 40. Radiation does not have an impact. Luckily, with endocrine therapy we don’t find it hastens menopause or causes women to go into early menopause, but it certainly causes menopausal symptoms.

What are the most common signs and symptoms of treatment-induced menopause that patients should be aware of?

This can unfortunately be confusing for many women, as many of the same signs and symptoms of menopause can be experienced just because of undergoing a breast cancer diagnosis, emotionally processing this huge life change and the stress and anxiety that comes with that.

Nonetheless, mood changes are common, such as significant anxiety and depression that are out of proportion to what patients have experienced in the past. Hot flashes, sleep disturbances and cognitive changes — such as difficulty focusing or word-finding difficulty — are also very common. Women will often report sexual dysfunction, including vaginal dryness and decreased or absent libido, as well as weight gain or trouble losing weight.

This is really significant for women. More than 95% of women actually gain weight on chemotherapy, which is surprising to many, and it can be very difficult to lose or maintain weight once we also start extended periods of endocrine therapy.

Are there ways to reduce the risk of premature menopause during cancer treatment, such as fertility preservation or ovarian suppression strategies?

Unfortunately, much of the risk of premature menopause from these treatments is based on biology and age. The risk is greater in women older than 40 at the time they receive chemotherapy, whereas women younger than 30 do not experience chemotherapy-induced amenorrhea, or lack of periods, as often. Ovarian function often returns in women under 40 — maybe 50% of the time — but the majority of women over 40 will not have return of ovarian function once they’ve had chemotherapy, and that’s a large proportion of our patients.

We do use ovarian function suppression, such as GnRH agonists like Lupron (leuprolide), given in partnership with chemotherapy in premenopausal patients who hope to preserve ovarian function or fertility. But the data behind this approach is mixed, so we caution patients that it’s not a surefire approach and does not guarantee return of ovarian function.

How does treatment-induced menopause affect long-term health, including bone density, heart health and cognitive function?

This is a super important question and truly an area of unmet need. Treatment-induced menopause affects each of those areas significantly, and we’re working to develop robust survivorship clinics to address these issues because many patients are surviving their cancer now, but we must ensure they do well for years after treatment.

Bone density is tremendously impacted by estrogen deprivation. Our bones rely on estrogen to stay healthy. Women with high-risk disease often need more estrogen deprivation to reduce recurrence risk, but this increases the chance of osteoporosis. Those on maximum endocrine therapy — aromatase inhibitors plus ovarian function suppression — are in a menopausal state. We don’t recommend this combination for more than five years due to osteoporosis risk, so after five years we switch them to tamoxifen to complete 10 years. We monitor bone density closely and encourage weight-bearing exercise, vitamin D and calcium intake.

For heart health, we know women in early menopause have an increased risk of cardiovascular disease, including heart attacks and heart failure. This is likely due to higher cholesterol levels, and unfortunately many of our therapies also contribute. Tamoxifen, however, can improve lipid profiles, so it doesn’t carry that same risk. Still, this remains an area of unmet need, and we aren’t sure of the best way to monitor these patients. Education and awareness are an important first step.

The cognitive impact is less clear. We know women who undergo surgical menopause (removing ovaries before natural menopause) face increased risk of dementia and cognitive impairment, but data on endocrine therapy’s impact is mixed.

For younger patients concerned about fertility and future pregnancies, what guidance can you provide before, during and after cancer treatment?

If patients are about to begin therapy, especially chemotherapy, it’s really important to have open, honest conversations with their providers about family planning. Meeting with a reproductive endocrinologist or fertility specialist early is key.

The gold standard is egg preservation, though it can be costly and time-consuming. We also support using GnRH agonists with chemotherapy as an alternative — this “calms” the ovaries, in theory protecting them from exposure — but while evidence shows it helps, it may not fully preserve fertility.

Importantly, we now have the POSITIVE trial to guide patients. About 500 women with early-stage, hormone-positive breast cancer paused endocrine therapy after two to three years to try to conceive. Around 75% successfully became pregnant and delivered healthy babies. They were able to stay off therapy for up to a year to breastfeed before restarting endocrine therapy, and this pause did not increase recurrence risk. This is really incredible data to finally have for these women and their families.

Reference

1. “Breastfeeding After Breast Cancer Proves Safe in Early Trial Results,” CURE, Aug. 31, 2025; https://www.curetoday.com/view/breastfeeding-after-breast-cancer-proves-safe-in-early-trial-results

Transcript has been edited for clarity and conciseness.

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