Tackling pain in childhood cancer survivors

The new two-year study will examine the biological pathways through which chemotherapy, a treatment used to kill cancer cells, can cause patients to experience chronic pain conditions even after they are cancer-free.

More than half of all childhood cancer survivors report chronic and progressively painful symptoms after treatment, often in their hands and feet. One member of the research team, Dr Richard Hulse from Nottingham Trent University, comments, “Ongoing pain post-treatment is a significant problem in children that live into adulthood and can severely impact their quality of life, but we still know little about the pathways and mechanisms driving this.”

Due to a lack of understanding of how chemotherapy affects peripheral nerves, which are linked with pain recognition processes, current medicines are limited in their ability to manage post-treatment pain.

At Nottingham Trent University, Dr Hulse and his team have previously found that exposure to chemotherapy in early life can damage nerve cells in the body that detect pain, changing the way that pain is perceived as a patient grows into adulthood.

When the body is exposed to toxic agents through treatments like chemotherapy, the natural immune system automatically responds by activating its white blood cells. These immune cells try to support damaged tissues and organs, including nerves, but because the immune cells themselves have been disrupted by toxic chemotherapy agents, this process can also cause harm.

The Nottingham researchers believe that white blood cells transfer mitochondria, which provide cells with energy, to damaged nerve cells as a means of rescuing their function and preventing pain.

However, chemotherapy-damaged white blood cells will transfer less mitochondria to nerve cells. If it were possible to transfer healthy mitochondria to protect nerve cells, this could be a pathway for minimising pain.

The study will investigate the potential for this exact process. Working with mice, researchers will be able to explore the interaction between nerve cells and the immune system.

Dr Hulse explains, “In normal cases, the body’s natural immune system would help preserve the mitochondria of nerve cells that detect pain – however, chemotherapy stops this from happening. We want to explore how the immune system and these nerve cells interact.

“Mitochondria are important as they provide the cells with energy. So, if functional healthy mitochondria are transferred, this may help nerve health. We believe this could provide a unique pathway to protect nerves from pain and provide an avenue to identify potential new treatments.”

Findings from this research could help to design new painkillers that are more effective at rescuing nerve function and alleviating pain in people who have undergone childhood cancer treatment.