The pain experienced by cancer patients, scientists hope, can be alleviated blocking a specific type of hormone-like molecule which is produced by tumours. It was revealed in a breakthrough study conducted by German scientists.
The biology of cancer pain is different to other types of pain, often rendering analgesic drugs ineffective.
But, in the new study, researchers at Heidelberg University showed that the molecules make nerve endings grow in nearby tissue, causing an acute sensation of pain.
The research could one day lead to drugs that can block pain locally at the tumour site.
The molecules highlighted by the latest study were known to play a role in the development of blood cells in the bone marrow.
However, this is the first time that the molecules have also been shown to have a role in causing pain.
The researchers hope that their work could lead to new drugs to block this action.
"Identifying one of the ways in which cancer causes pain - in fact, perhaps the main mechanism - is a crucial step towards drugs that could bring relief to cancer sufferers across the world," the BBC quoted Dr. Mark Matfield, a scientific adviser to the Association for International Cancer Research, as saying.
Dr. Joanna Owens, of the charity Cancer Research UK, said: "It's important that we continue to improve pain relief for people with cancer, and this study reveals an intriguing new avenue to explore."
She added: "What's particularly encouraging is that this research could one day lead to drugs that can block pain locally at the tumour site - which could ultimately lead to more effective pain relief with fewer side effects."
The study has been published in the journal Nature Medicine.