According to MedicalXpress.com, opioid drugs used to treat pain in postoperative and chronic cancer patients may stimulate growth and spread of tumors, according to two studies and a commentary in the 2010 annual Journal Symposium issue of Anesthesiology, which is the academic journal of the American Society of Anesthesiologists.
Opiate based painkillers have often been the choice for these patients, but a 2002 study suggested that opioids can stimulate the growth of cancer. Laboratory research from University of Chicago Medicine and a genetic study from the university of North Carolina Medical Center both argue the mu opioid receptor plays an important role in tumor progression and support a therapeutic role for opiate antagonists.
University of Chicago Medicine’s study shows how opioids already present in the body can enhance the malignant tendencies of human lung cancer cells transplanted into mice, even without morphine addiction. University of North Carolina Medicine Group’s study found that cells from various types of human lung cancers had 5 to 10 times as many opioid receptors as non-cancerous lung cells. In the final paper for the journal, one doctor’s team looked at survival rates of an earlier study done on more than 2,000 breast cancer patients. Women being treated for invasive breast cancer who had a tiny genetic mutation that made them less sensitive to opiates were more likely to be alive 10 years after cancer treatment.
The notion that opioids could increase cancerous growth began in 2002. Later, a randomized palliative care found that patients who received spinal opiates rather than systemic pain relief survived longer. Both studies showed that breast or prostate cancer patients who received local or regional anesthesia rather than systemic morphine survived longer. But, more recent studies on colon cancer did not confirm this relationship. The university of Chicago Medicine study actually used an drug that blocked the peripheral side effects of opiates, such as nausea and constipation, without disrupting pain relief. Patients using this opiate blocker lived longer. This began a study, looking at the many peripheral side effects of opiates and the benefit of blocking those.