According to a new study, morphine may be combined with tumor growth in mice. At present there is no scientific data that indicates morphine or similar pain medications will lead to increased cancer growth in humans. However, researchers say their findings warrant further studies for managing cancer pain.
Researchers from the University of Minnesota Cancer Center found doses of morphine, similar to doses given to cancer patients to manage severe pain, provoke signals in endothelial cells, or cells that form blood vessels, and activate mitogen-activated protein kinase (MAPK). MAPK promotes endothelial cell multiplication and angiogenesis, or formation of new blood vessels. Angiogenesis can cause tumor growth by providing nutrients to growing tumors and by transporting cancer cells from a tumor to other parts of the body.
Lead researcher Kalpna Gupta, Ph.D., from the University of Minnesota felt that, despite the widespread use of morphine to treat pain in many medical conditions like cancer, little was known about how this drug affects blood vessels or cancer. Our study shows that morphine stimulates the formation of new blood vessels inside the tumor, which in turn allows increased growth of tumors in mice. Hence Authors of the study note that morphine did not promote initial or early growth of tumors in this study.