Hormone therapy is an important part of treatment for many people with hormone receptor positive breast cancer. Medicines such as tamoxifen and aromatase inhibitors can help reduce the risk of the cancer returning by limiting the effect of oestrogen on breast cancer cells. For some women, especially those who are postmenopausal, aromatase inhibitors are prescribed for several years.
While long term hormone therapy can offer important protection against recurrence, it can also affect bone health. Understanding this possible side effect and taking steps to protect your bones can help you stay strong and active during and after treatment.
Why Can Hormone Therapy Affect Bone Health?
Oestrogen plays an important role in maintaining healthy bones. It helps balance the natural process through which old bone is broken down and new bone is formed. When oestrogen levels become very low, bone loss can happen more quickly.
Aromatase inhibitors lower oestrogen levels significantly and may therefore increase the risk of osteopenia or osteoporosis. Osteopenia means that bone density is lower than normal, while osteoporosis means the bones have become weaker and are more likely to fracture.
Tamoxifen affects bone health differently. In postmenopausal women, it may have a protective effect on bones, although its effects can vary depending on age and menopausal status.
The good news is that bone health can be monitored and managed throughout treatment.
How Is Bone Density Monitored?
Your doctor may recommend a bone mineral density test, commonly called a DEXA or DXA scan. This is a simple test that measures bone density, usually at the hip and spine.
Your doctor may recommend a baseline scan before starting certain hormone therapies and repeat testing at appropriate intervals. The timing depends on factors such as your age, menopausal status, existing bone density, treatment plan and other risk factors for fractures.
Regular monitoring helps identify bone loss early, when steps can be taken to reduce further deterioration.
Nutrition Matters
A balanced diet is an important part of maintaining strong bones. Calcium and vitamin D are particularly important because they support bone formation and calcium absorption.
Good sources of calcium include milk, yoghurt, cheese, certain leafy vegetables, tofu and calcium fortified foods. Vitamin D can come from sunlight, food and supplements when recommended by your doctor.
It is important not to start high dose calcium or vitamin D supplements on your own. Your doctor can assess your diet, blood test results and overall health to determine whether supplementation is appropriate.
Stay Physically Active
Regular physical activity can support both bone strength and overall wellbeing during breast cancer treatment.
Weight bearing activities such as walking, climbing stairs and dancing can help maintain bone strength. Resistance exercises using weights, resistance bands or body weight can also help maintain muscle and bone health.
If you have significant bone loss, joint problems or another health concern, speak with your doctor or physiotherapist before starting a new exercise programme. The goal is to choose activities that are safe and sustainable for you.
When Are Medicines Needed?
Lifestyle changes may not be enough for everyone. If bone density is significantly reduced or your risk of fracture is high, your doctor may recommend medicines that help slow bone loss and reduce fracture risk.
Depending on your individual situation, options may include bisphosphonates or other bone strengthening medicines. Your oncologist may work together with a specialist such as an endocrinologist or rheumatologist when needed.
The decision is based on your bone density, age, menopausal status, fracture risk and cancer treatment plan.
Do Not Stop Hormone Therapy Without Speaking to Your Doctor
If you are worried about bone loss, it is important not to stop hormone therapy on your own. These medicines may be an important part of reducing your risk of breast cancer recurrence.
Instead, discuss your concerns with your oncologist. In many cases, bone health can be monitored and managed while you continue your cancer treatment.
Dr. Pragati Singhal
