What Are the Side Effects of Hormone Therapy for Breast Cancer?

Hormone therapy for breast cancer commonly causes hot flashes, night sweats, joint and muscle aches, tiredness, vaginal dryness and mood changes. Less often, it can cause blood clots, thinning bones or changes in the womb lining. Most people get some of these, and few get all of them. How much you feel depends on the drug, tamoxifen or an aromatase inhibitor, and most of it can be eased.

Dr. Sandeep Nayak, who provides the cancer treatment in Bangalore, says women are often told about the tablet but not about the years of living with it. “Hot flashes, sore knees, being awake at three in the morning. None of it is dangerous, but it wears you down, and it’s the main reason women quietly stop the tablet. Please don’t. Come and tell us. A different tablet, a small change, a simple cream, a bone scan. There’s usually something. Stopping on your own costs you protection we’ve worked hard to give you.”

These are the ones most women meet, along with what tends to ease them:

• Hot flashes and night sweats. They’re the most common of all, and they can wreck your sleep. Dressing in layers, keeping the bedroom cool and avoiding hot drinks late in the day help. Non-hormonal medicines such as venlafaxine can also be prescribed. Hormone replacement is generally avoided after breast cancer.
• Aching joints and muscles. This is especially common with aromatase inhibitors, and it’s often worse in the morning. Regular exercise helps the most, along with simple painkillers. Acupuncture is recommended in guidelines for this particular problem, and sometimes switching to another aromatase inhibitor helps.
• Vaginal dryness, a lower sex drive and mood changes. They come from low estrogen. Non-hormonal moisturisers and lubricants, used regularly and not just when it hurts, often help. Whether to use any vaginal estrogen is debated, so ask your team. Tamoxifen can also cause discharge or irregular bleeding.
• Tiredness, weight change and a foggy head. Some women notice weight gain or find it harder to concentrate. Sleep, steady exercise and a balanced diet make a difference. Our diet counselling team can help with the weight side.

A few effects aren’t just uncomfortable, and they need attention:

• Blood clots. They’re more of a risk with tamoxifen, and less so with aromatase inhibitors. A swollen, painful leg, or sudden breathlessness or chest pain, needs help the same day. Don’t wait for your next appointment.
• Changes in the womb lining on tamoxifen. Any unusual vaginal bleeding, and especially bleeding after menopause, should be checked promptly. Most causes are harmless, but it’s the one to rule out.
• Thinning bones, especially on aromatase inhibitors. A bone density scan before you start, calcium, vitamin D, regular weight-bearing exercise, and sometimes a bone-protecting medicine are the usual plan. Tamoxifen may actually protect bones after menopause. Our breast cancer treatment in Bangalore page explains how it’s followed up.
• Low mood and anxiety. It’s easy to put these down to just being tired, but they’re a real side effect and a real reason women stop. Our onco-psychology page explains how that support works.

There’s no single fix, because every woman’s mix of side effects is different. A few things decide the plan:

• Which drug you’re on. Tamoxifen and aromatase inhibitors have different profiles, and some women do far better on one than the other. Switching is a legitimate option.
• Whether you’ve been through menopause. It shapes which drug you’re offered, and ovarian suppression adds menopause-type symptoms of its own.
• Your bones and your other conditions. A history of clots, womb problems or osteoporosis changes what’s safe, and it decides how closely you’re monitored.
• Which side effect bothers you most. Sleep loss from night sweats might come first for one woman, and aching joints for another. Tell your team what matters most to you.
• How much benefit you’re getting. Your risk of recurrence decides how hard it’s worth working to stay on treatment, and it’s reviewed regularly.

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