Rebekka Haefeli: Every year in Switzerland, around 6,500 patients are diagnosed with breast cancer. The risk increases with age, and most patients are over 50 when the cancer is detected. For many, that also means that they are already going through menopause or have long since passed it. This phase is also referred to as postmenopause. Many patients in this phase of life are familiar with menopausal symptoms.
Petra Stute: Hot flushes and sweating are probably the best-known symptoms. But there are also many others, for example sleep disturbances, mood swings, cognitive symptoms, commonly referred to as brain fog. For example, struggling to remember words or names. Or walking into a room and suddenly forgetting why you went there in the first place.
Rebekka Haefeli: This is Petra Stute. She is an expert when it comes to menopause. She lists several additional symptoms. And these are only a few examples.
Petra Stute: There are also changes in the genital area. This includes vaginal dryness, bladder irritation or pain during sexual intercourse. Some patients also have joint and muscle pain.
Rebekka Haefeli: The physician Petra Stute from Inselspital Bern conducts research with support from the Swiss Cancer Research foundation. Her current research project focuses on breast cancer treatment in postmenopausal patients, the time after the final menstrual cycle. Her goal is clear: Patients should receive safe and effective treatment while maintaining the best possible quality of life. So that they do not stop cancer therapy because side effects become too severe. That would increase the risk of recurrence. This is Wissen gegen Krebs, the podcast of the Swiss Cancer Research foundation. I am Rebekka Haefeli.
Rebekka Haefeli: Some forms of breast cancer are hormone-dependent. This is called hormone receptor-positive breast cancer. That means that ostrogen can stimulate cancer growth. That was the case for Ms. S.. She is now 61 years old and received her diagnosis in January 2025.
Ms. S.: During a routine examination, my gynecologist noticed something. We also saw it on ultrasound. I saw that there was something that didn’t belong there. But I didn’t feel anything. I hadn’t noticed anything before either. At that point, I felt completely healthy and fit. It never crossed my mind that something could be wrong. It is a complete shock. In the middle of life, a healthy life, and suddenly you feel something is wrong.
Rebekka Haefeli: Ms. S.’s story since the diagnosis is typical for many patients who face this diagnosis after menopause. Let’s go back a bit. Before her breast cancer diagnosis, Ms. S. was on hormone therapy. She used estrogen patches to manage menopausal symptoms. Like many other patients. Estrogen therapy is also available as a gel. For Ms. S. the treatment worked well. Her symptoms were under control. But she had to stop immediately after the diagnosis.
Ms. S.: For me, that was the hardest part, besides the diagnosis, that I had to stop the hormone patches immediately, from one day to the next. And suddenly all the menopausal symptoms came back in full force.
Rebekka Haefeli: Estrogen could cause hormone-dependent cancer to grow again. That is why patients with this type of breast cancer are advised to stop hormone therapy immediately. And more than that, they receive anti-hormone therapy. This ensures that estrogen production is suppressed. Because even after menopause, the body still produces small amounts of estrogen.
Petra Stute: Not only the ovaries produce estrogen, but also small amounts are produced in fatty tissue.
Rebekka Haefeli: So there is still some estrogen in the body, says Petra Stute from Inselspital Bern. She is deputy head physician and head of the department of gynecological endocrinology and reproductive medicine.
Petra Stute: In patients with hormone receptor-positive breast cancer, the goal is to reduce estrogen sources as much as possible. That means it is not enough that the ovaries stop producing estrogen. The aim is also to minimise ostrogen production in fatty tissue. That is why anti-estrogen therapy is added on top of natural menopause, so that estrogen production is reduced as much as possible.
Rebekka Haefeli: What this means in practice we now hear from Ms. S. When I sit at her table at home, I ask her about the therapy. She brings a box of tablets and a detailed leaflet. She warns me not to read the side effects. She doesn’t want to know. I take the leaflet with me. Later I read that she takes an aromatase inhibitor. The leaflet says: the following side effects may occur, many due to hormone suppression. That explains the long list, including menopausal symptoms.
Rebekka Haefeli: After the first ultrasound, when the tumor was seen, she had no idea what would follow.
Ms. S.: Then everything happened quickly. I am very grateful that it went so fast. I had a mammogram. At first, they found nothing. Only after a closer look did they see it. The next day, a biopsy. Within two weeks I had the result. It was hormone-dependent breast cancer. I didn’t understand what that meant. I didn’t even know there were different types.
Rebekka Haefeli: Fortunately, the breast cancer was detected early. She stopped hormone therapy immediately. Then she had surgery. Afterwards, radiotherapy was recommended. No metastases were found. She could have felt relieved if not for the menopausal symptoms. They returned along with therapy side effects. It is not so important what causes which symptom. But her quality of life is affected.
Ms. S.: The hot flashes are the worst. And also vaginal dryness. I had many infections. Fungal infections, itching. Very uncomfortable. That was the hardest to cope with. After many treatments I received vaginal estrogen cream. Since then it is mostly fine.
Rebekka Haefeli: Petra Stute says studies now support low-dose vaginal estrogen.
Petra Stute: In other words, in most countries it is also possible to use very low-dose vaginal estrogens, for example to treat vaginal dryness, because these simply act locally and therefore do not constitute whole-body hormone therapy, as is usually the case with conventional hormone therapy.
Rebekka Haefeli: Other side effects were strongest at the beginning. Nausea, dizziness. Palpitations. Feeling stiff and exhausted in the morning. Pain everywhere. Fortunately, that has improved. But some risks remain.
Ms. S.: I have bone density checked once a year. Because of osteoporosis risk. The fact that it can affect your bones – that it can put you at risk of osteoporosis – that worries me. I don’t know what will happen. It depends. I’m lucky in that respect too, as I have above-average bone density for my age. That’s a good starting point, at least. I’m not in the red yet. If it drops, I don’t know what I will do. Osteoporosis – then you have to treat it again. That’s also… Well, where does that lead?
Rebekka Haefeli: Petra Stute and her team see many patients like her. Up to 40 percent stop therapy due to symptoms. This should be avoided. Because therapy reduces recurrence risk. Her study aims to identify risk factors for stopping therapy.
Petra Stute: Several centers in Switzerland are involved. Symptoms are tracked over time. Blood samples are taken. Estrogen levels measured. Also, whether medication is taken.
Rebekka Haefeli: Around 100 patients are planned.
Petra Stute: The goal is to identify profiles of patients likely to stop the anti-estrogen therapy. If identified early, support can be provided. To help them continue treatment, without developing all those symptoms that might lead to a stop of the therapy.
Rebekka Haefeli: The aim is early identification and better support. Options include closer follow-up, psychological support, and targeted treatments to reduce hot flashes. According to Dr Petra Stute, these do in fact exist.
Petra Stute: There are non-hormonal medications for hot flashes. Since 2024, a new drug targets hot flashes in the brain. Another will follow soon. So there are good options. Also plant-based treatments. Acupuncture and hypnosis.
Rebekka Haefeli: And one special therapy:
Petra Stute: There is another treatment, stellate ganglion block. A nerve bundle in the neck is targeted. And this forms part of the autonomic nervous system. Local anesthetic is injected there under ultrasound guidance. Hot flashes decrease by 50 to 60 percent. The effect lasts six to eight weeks. So it’s essentially a good, non-medicinal treatment, but of course it takes some getting used to, because when anesthetists carry it out, it is done in an operating setting. And if you’re not aware of that, it’s likely to put you off. But it actually only hurts as much as having a blood test. So it’s really not that bad.
Rebekka Haefeli: Ms. S. says she has learned to live with it. And even if she isn’t sleeping well, she can cope with that for the time being. But she has thought about stopping therapy. So far, she continues.
Frau S.: I think about stopping again and again. But the fear of recurrence and going through everything again is greater than taking the medication.