Protecting our bone health after cancer

Cancer can have a significant impact on bone health. The disease itself, as well as treatments like chemotherapy, hormone therapy and radiation therapy may weaken bones and increase the risk of fractures. Additionally, certain types of cancer may directly involve the bones, such as bone metastases. Having a good understanding of our skeletal system, how it works and how to protect our bone health will help to empower you as during and after cancer treatment.

Our skeletal system

The skeletal system is composed of 206 bones, which provide structure and support to the body. It also protects vital organs, stores and releases fat and minerals, produces blood cells and facilitates all movement.

Bone health and cancer: understanding the skeleton

What are the functions of our bones?

Protection: Bone is essential to protect our vital organs, for example, the skull protects the brain, the ribs protect the lungs, and the sternum protects the heart.

• Production: Bone marrow produces red blood cells (carrying oxygen and iron), white blood cells (fighting infection), and platelets (clotting).

  
  

• Storage: Bones store essential minerals like calcium and phosphorus, which are important for muscle and nerve function.

  
  

• Movement: Muscles attach to bones using tendons and ligaments connect bones to stabilise joints; this allows for safe and effective movement.

  
  

• Support: The skeletal system maintains an upright body position, which is essential for us to function effectively. Take a moment to imagine your body without bones!

What is bone regeneration?

Our skeleton is a metabolically active organ that undergoes constant regeneration; it completely remodels itself around every 10 years throughout our life.

The remodelling cycle consists of three consecutive phases:

• Resorption: osteoclasts digest old bone.

• Reversal: mononuclear cells appear on the bone surface

• Formation: when osteoblasts lay down new bone until the resorbed bone is completely replaced.

How does cancer treatment impact bone health?

Cancer can directly impact bone health, either from the disease itself, but also from treatments such as chemotherapy, hormone therapy and radiation therapy.

• Chemotherapy

  Chemotherapy drugs can directly damage bone cells, leading to bone loss. Side effects like nausea, vomiting, and loss of appetite may also, if persistent, lead to malnutrition and decreased bone density.

• Radiotherapy

  Radiation therapy can directly damage bone tissue, leading to bone loss and an increased risk of fractures; the type of radiation used and the area being treated will influence this risk.

• Hormone Therapy

  Certain cancers are hormone-sensitive, meaning they are fuelled by hormones like oestrogen or testosterone. Hormone therapy, which blocks or reduces these hormones, can have both positive and negative effects on bone health. For example, hormone therapy can increase the risk of bone loss, especially in postmenopausal women with breast cancer.

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What are bone metastases?

In some cases, cancer cells may spread and result in bone metastases. It's important to be aware that not all cancers affect bone tissue in the same way; the type of cancer, stage and individual factors can influence the specific type of bone metastasis. Around 70% of people with bone metastases have breast or prostate cancer diagnosis (1). For some people, this may be a significant concern following cancer diagnosis, particularly if their condition is more advanced. Having a good understanding of the skeletal system, your individual risk of bone complications and how to optimise and protect bone health will empower you during and after cancer treatment.

There are three types of bone metastases:

• Osteolytic: Loss of bone, causing loss of density like ‘honeycomb’ (most common in: non-small cell lung, renal, thyroid)

• Osteoblastic: Building of bone, the addition of excessive, poor quality bone added to existing bone (most common in: prostate, small cell lung, Hodgkin lymphoma)

• Mixed: A combination of the above (most common in: breast, skin and GI)

What are the signs and symptoms of bone metastases?

Sometimes, bone metastases will cause no symptoms, for others it may be more problems. Feeling clued up on the symptoms of bone metastases can help you feel more in control. Signs and symptoms may include:

• A continuous, ache or sharp pain that can be worse at night or when moving

• High levels of calcium  in the blood (from bone) can cause nausea, vomiting, constipation, confusion, and extreme thirst.

• Pressure on the spinal cord can cause loss of balance, weakness, numbness, and incontinence.

What other conditions can impact bone health?

Menopause and low oestrogen

Certain hormone therapy that lowers oestrogen level in the body will induce menopausal symptoms. Oestrogen plays a vital role in bone regeneration by stimulating osteoblasts (building bone). With lower levels of oestrogen, there is less building of bone and it becomes more brittle and vulnerable to fracture. It can also cause joint aches and pains (arthralgia) which can be difficult to manage.

Thyroid

Hyperthyroidism is an increased level of the hormone thyroxine, which stimulates osteoclastic activity (bone reabsorption) and creates brittle bone. Controlling this with medication can help to address this issue and protect bone health.

Conversely, hypothyroidism (lower levels of thyroixine) does not directly cause lower bone density, but thyroxine replacement medication used in hyperthyroidism must be closely monitored; if the dose is too high, it can cause the above symptoms of hyperthyroidism.

Diabetes 

High blood sugar levels can impair bone metabolism, leading to decreased bone density. Additionally, diabetes can increase the risk of infections and other complications that can further weaken bones.

Excessive corticosteroid use: This can reduce calcium absorption and increase bone reabsorption, resulting in more brittle bones. Steroid use should be closely monitored by your medical team.

Osteoarthritis: Loss of cartilage can increase inflammation and friction, impacting bone density and pain.

Gastrointestinal issues: Persistent issues with nausea, vomiting and loose stools may result in poor absorption of essential vitamins and minerals through our diet - such as Vitamin D and Calcium, which are needed for bone health.

How to Protect Your Bones During and After Cancer Treatment

Exercise can help with bone density

Protecting bone health during and after cancer treatment is crucial. Here are some tips:

• Regular Exercise: Weight-bearing is essential for bone regeneration and maintaining bone density. Weight-bearing exercises, such as walking, jogging, and dancing, can help strengthen bones. High impact involves running and dancing, which is repetitive impact through the bones. Low impact exercise such as walking, A graded approach to resistance training can also help to load our bones and improve their strength: farmers carry, squats, deadlifts. If you have a known large weight-bearing metastasis, contact your doctor or physiotherapy for modification advice.

• Healthy Diet: A diet rich in calcium, vitamin D, and other essential nutrients is important for bone health. Contact your doctor or dietitian for more advice if needed.

• Smoking: Nicotine slows the production of osteoblasts which build bone and decreases the absorption of calcium needed for bone health.

• Medication: Your doctor may prescribe medications to help prevent bone loss, such as bisphosphonates or denosumab.

• Regular Check-ups: Schedule regular bone density scans and consultations with your doctor to monitor your bone health.

Conclusion

Bone health is a valid concern for people with cancer. By understanding the factors that can affect bone health and taking proactive steps to protect your bones, you can reduce your risk of complications, optimise your treatment outcomes and improve your overall quality of life. If you have any questions, worries or need further support on this topic, please contact your oncology team or reach out to Hannah at hannah@strongerthan.co.uk.

References:

(1)   Macedo F, Ladeira K, Pinho F, Saraiva N, Bonito N, Pinto L, Goncalves F. Bone Metastases: An Overview. Oncol Rev. 2017 May 9;11(1):321. doi: 10.4081/oncol.2017.321. PMID: 28584570; PMCID: PMC5444408.