A new study shows that morphine stimulates tumour blood supply in mice.

Morphine is commonly given to relieve severe cancer pain. But experiments in mice suggest that the drug has an effect on tumour growth. Researchers at the University of Minnesota have shown how morphine triggers a signalling pathway in endothelial cells (the cells that line the blood vessel).

The end effect is stimulation of the growth of the tiny blood vessels that carry nutrients to the tumour. However, morphine did not trigger the growth of new tumours - merely enlarged those that were already there. The study does not suggest that morphine will increase the growth of human cancers. But it may lead to research on painkilling drugs that do not have the ability to stimulate the growth of blood vessels within tumours - this might be a safer approach to treating cancer pain.

Source

Cancer Research 1st August 2002