When Cancer Treatment Affects the Joints: Understanding Immunotherapy-Related Rheumatological Side Effects
“I am grateful to have seen Dr Animesh Singh following joint complications due to cancer medication. I felt so reassured after my diagnosis and treatment plan. Dr Animesh Singh is an exceptional Rheumatologist.”
— Patient treated for immunotherapy-related joint inflammation
Modern cancer treatments such as immunotherapy and targeted therapies have transformed survival and recovery for many people living with cancer. These medicines work by helping the immune system to recognise and attack cancer cells — but sometimes, this heightened immune activity can also cause inflammation in other parts of the body, including the joints, muscles, and connective tissues.
Why joint problems can occur
Immunotherapy drugs (including checkpoint inhibitors) act by taking the “brakes” off the immune system. While this helps destroy cancer cells, the same process can occasionally trigger immune-related side effects — known as immune-related adverse events (irAEs).
When this inflammation affects the joints, it can resemble conditions such as rheumatoid arthritis, polymyalgia rheumatica, or myositis, even in people who have never had these problems before.
Typical symptoms to watch for
Joint pain, swelling, or stiffness
Aching shoulders, hips, or knees
Morning stiffness lasting more than 30 minutes
Fatigue and reduced mobility
Muscle pain and/or weakness
These symptoms can appear during treatment or even months or even years after immunotherapy has finished. It’s important not to ignore them, as early recognition and treatment can make a big difference to recovery.
How rheumatologists can help
Specialist input from a rheumatologist experienced in immunotherapy-related inflammation is often invaluable. After detailed assessment and investigations, treatment may include:
Short-term anti-inflammatory medication or steroids
Disease-modifying drugs or biologic drugs to calm immune overactivity
Careful coordination with your oncology team to ensure your cancer therapy continues safely
The goal is always to reduce inflammation, relieve pain, and maintain joint function — without compromising cancer treatment.
A collaborative approach
I work in close collaboration with oncologists and haematologists to ensure that patients receive joined-up care. Many patients describe feeling reassured to have an explanation for their symptoms and a clear, balanced treatment plan.
If you are on immunotherapy and develop new or unexplained joint or muscle pain, speak to your oncology team or GP and ask for a referral to a rheumatologist familiar with immune-related side effects.
Dr Animesh Singh, Consultant Rheumatologist. GMC: 6130215
Please note, these posts are for general information only and do not constitute medical advice. Dr Singh would encourage you to speak to your healthcare professional to be assessed and managed for your specific symptoms.