Common Pain Medication Fuels Cancer Growth

Friday, November 27, 2009 by: Sherry Baker, Health Sciences Editor
Tags: pain medication, cancer, health news

(NewsTarget) Painkillers known as opiates are widely used to treat both acute and chronic pain. Morphine, in particular, is often used to relieve the pain experienced by cancer patients. But now comes evidence from two new studies that strongly indicates opiate-based painkillers actually fuel the growth and spread of malignancies.

The research presented in Boston on November 18, 2009, at "Molecular Targets and Cancer Therapeutics," a joint meeting of the American Association for Cancer Research, the National Cancer Institute, and the European Organization for Research and Treatment of Cancer, advances the concept that opiate drugs are cancer promoters. The research also explains how protecting cancer cells from opiates may reduce cell proliferation, invasion and migration.

The concept that opiate drugs used to help cancer patients might be contributing to cancer recurrence developed about eight years ago from several unrelated clinical and laboratory studies. First, a 2002 palliative care study found patients who received spinal rather than systemic pain relief from opiate drugs lived longer. A short time later, Jonathan Moss, professor of anesthesiology and critical care at the University of Chicago, reported that several cancer patients receiving a selective opiate blocker called methylnaltrexone (MNTX) which was developed in the 1980s to treat opiate-induced constipation lived far longer than they were expected to. Other studies had similar results.

"These were patients with advanced cancer and a life expectancy of one to two months yet several lived for another five or six. It made us wonder whether this was just a consequence of better GI function or could there possibly be an effect on the tumors," Moss said in a press statement.

Patrick A. Singleton, PhD, assistant professor of medicine at the University of Chicago Medical Center, along with Moss, Joe G.N. Garcia, MD, professor of medicine at the University of Chicago, and colleagues decided to investigate the many peripheral effects of opiates that might encourage cancer growth and the potential benefits of blocking those effects. In laboratory studies using both cell cultures and mice, the scientists found that morphine did directly rev up the proliferation of tumor cells. It also inhibited the immune response, and promoted angiogenesis (the growth of the blood vessels that help "feed" tumors and allow them to thrive). In the research just presented by Singleton and colleagues, they focused on the mu opiate receptor as a regulator of tumor growth and metastasis and they documented the ability of MNTX to block the cancer-promoting effects of opiates on this receptor.

Bottom line: it appears time for doctors and patients to consider all the side effects of opiate pain relievers, including the fact they may spur cancer to grow. Blocking the cancer-fueling ability of opiates and/or using them for as short a time as possible -- or not at all unless absolutely necessary -- appears to be the safest, and healthiest course of action.

For more information:
http://www.aacr.org/home/scientists/meetings...

About the author

Sherry Baker is a widely published writer whose work has appeared in Newsweek, Health, the Atlanta Journal and Constitution, Yoga Journal, Optometry, Atlanta, Arthritis Today, Natural Healing Newsletter, OMNI, UCLA's "Healthy Years" newsletter, Mount Sinai School of Medicine's "Focus on Health Aging" newsletter, the Cleveland Clinic's "Men's Health Advisor" newsletter and many others.