Finding out about medically-induced early menopause

Early menopause (EM) can be caused by medical treatment, including chemotherapy, radiotherapy, bone marrow/stem cell transplants, or surgical removal of both ovaries (bilateral oophorectomy). In some cases, surgical removal of the uterus (without removing the ovaries) or ovarian surgery (for example to remove cysts) can lead to EM. Reasons for having a bilateral oophorectomy or hysterectomy include cancer, endometriosis, fibroids, or to reduce cancer risk in women with particular gene mutations including BRCA 1/2 or Lynch Syndrome. Women who still have their ovaries and are undergoing ovarian suppression therapy with monthly gonadotrophin releasing hormone (GnRH) agonist injections (e.g. goserelin) for breast cancer or endometriosis usually experience menopausal symptoms; but they are not considered to have EM because ovarian suppression is reversible when therapy is stopped.

To learn more about ovarian suppression therapy, please see the Box at the end of this Talking Point.

Cancer treatment-induced EM: what women were told

Women’s experiences of being informed that EM may result from cancer treatment varied according to the type of treatment they had. Women who experienced surgical removal of both ovaries or a radical hysterectomy said they were advised these procedures would cause fertility loss and EM.

Sylvia recalled being told about the impacts of having her uterus and ovaries removed as part of her uterine cancer treatment.

A few women who had their ovaries and/or uterus removed felt they were not given enough information about what EM would be like, or how to treat menopausal symptoms (see Taking hormone-based medications for early menopause and Non-hormone based medications for early menopause). Tracey, who had Lynch Syndrome, delayed having a prophylactic (preventative) bilateral salpingo-oophorectomy (BSO) to reduce her cancer risk for several years because of concerns about EM symptoms. The doctors at the gynae-oncology clinic she attended ‘weren’t very helpful’ and it was not until she was given a ‘heap of information’ through a research project she participated in that she decided to have the surgery.

Naomi said her oncologist had told her she would likely experience early menopause after ovarian surgery following her second recurrence of ovarian cancer, but didn’t tell her much more about it.

Chemotherapy may not necessarily lead to EM: the risk of EM increases with increasing age, particular chemotherapy type, and dose. GnRH agonists (e.g. goserelin) are now being used to try and protect the ovaries from the effects of chemotherapy in younger women. Some women received clear information about the potential impact of chemotherapy on their ovaries and menstrual cycle.

Maree described what she was told about the effects of chemotherapy (for breast cancer) on her menstrual cycle.

Some women who had chemo, radiation or other treatments such as bone marrow/stem cell transplants reported that in discussions about the side effects of treatment, health practitioners focused on impacts on menstrual periods or fertility loss, rather than EM. As Yen-Yi said, “… in the course of so many discussions probably no-one had really set out clearly to me other [effects of chemotherapy and radiotherapy] and all I could think of was the menstrual cycle.”

Although Julia knew chemo, radiation, and a stem cell transplant for Hodgkin’s Lymphoma had caused her to become infertile, she said neither she nor her treating health practitioners made ‘the link’ with menopause until she was referred to a menopause clinic.

A few women who underwent hormone therapy with tamoxifen or an aromatase inhibitor as part of breast cancer treatment were aware their menopausal symptoms could be temporary. However, they were uncertain about what would happen to their fertility and menstrual periods once they stopped the medication, especially because they had been advised to take it for up to ten years, when they would be in their early to mid 40s.

Yen-Yi described what she had been told about early menopause during breast cancer treatment and said whether or not her periods would return when she stopped taking hormone (adjuvant endocrine) therapy was a ‘grey area.’

Worrying about survival, fertility loss, and early menopause

Concerns about mortality or fertility preservation shaped several women’s experience of being informed about EM. Women commonly felt that, for themselves and their doctors, survival had been the first priority, followed by fertility preservation , while EM was something to ‘deal with later’, as Alex put it.

Kate described what it was like finding out she had breast cancer, then finding out about the recommended treatment and its implications, including menopausal symptoms.

A few women commented that the intense early focus on cancer survival or fertility preservation meant they didn’t fully understand what EM would be like. Others commented that when they first experienced menopausal symptoms, they thought they were a sign of cancer coming back (see Women’s experiences of symptoms of early menopause – Part 2 and Emotional impact of early menopause and fertility loss).

In deciding to have a bilateral oophorectomy after finding out she carried the BRCA1 gene mutation, Theresa’s focus was on reducing her cancer risk rather than on early menopause.

Finding out about medically-induced EM as a result of treatment for non-cancerous conditions

Among the few women who had hysterectomies or ovarian surgery to treat endometriosis or ovarian cysts, experiences of being informed of medically-induced EM also varied. Some recounted not finding out that their surgery had caused EM until they sought help for menopausal symptoms afterwards.

Mary had one ovary removed at age 14 and repeated surgeries on her remaining ovary for cysts and benign tumours. She described her experience of being diagnosed with Premature Ovarian Insufficiency at age 37.

However, other women had some forewarning from health practitioners that their surgery might cause EM.

Natalie said her gynaecologist left her ovaries in when she had a hysterectomy for endometriosis, hoping this would prevent her from experiencing EM, but unfortunately this ‘didn’t work.’

What is Ovarian Suppression Therapy?

Ovarian suppression therapy refers to any treatment that lowers or stops the amount of oestrogen made by the ovaries. It includes chemotherapy, radiotherapy, bilateral oophorectomy, and the use of certain drugs. Ovarian suppression can be permanent or temporary. Bilateral oophorectomy before the age of 45 causes early menopause (EM). Chemotherapy and radiotherapy before age 45 may cause EM. Women undergoing ovarian suppression therapy with gonadotrophin-releasing hormone (GnRH) agonists such as goserelin (ZOLADEX) for breast cancer or endometriosis usually experience menopausal symptoms; but they are not considered to have EM because the ovarian suppression is reversible when therapy is stopped. If women have chemotherapy followed by ovarian suppression therapy, they may develop EM due to chemotherapy, but EM may be hidden until their ovarian suppression is stopped and they find that their menstrual periods do not return.

Tamoxifen may cause menopausal symptoms as it has an anti-oestrogen effect on some parts of the body (breast and brain temperature regulation) but does not cause menopause itself. Aromatase inhibitors (e.g. exemestane, letrozole, anastrozole) block the chemical pathway producing oestrogen, causing very low oestrogen levels and thus menopausal symptoms, but do not cause menopause itself.

Therapy involving GnRH agonists, tamoxifen or aromatase inhibitors, may also be referred to as “hormone therapy” or “adjuvant endocrine therapy”. The term “hormone therapy”, used to describe treatments where the aim is to block or lower oestrogen in the body, can be confusing as it is similar to the term “hormone replacement therapy” (HRT). However, HRT is designed to increase oestrogen levels to relieve menopause symptoms.

Further information:

Talking Points (Women)

Talking Points (Health Practitioners)

Other resources

Healthtalk Australia site

External sites

* Iatrogenic means medically-induced.