Study warns of death risk from opioids after lung cancer surgery

Sept. 12 (UPI) -- People who take opioids for six months or more to ease their pain after lung cancer surgery face a 40% higher risk of dying from any cause within the next two years, a study published Monday suggests.

The research, which appeared online in Regional Anesthesia & Pain Medicine, published by the British Medical Journal, said the study's participants were likelier to fall into this new opioid use category if they were older men on chemotherapy who had longer hospital stays and experienced pre-surgery anxiety and insomnia.

Another factor associated with a greater likelihood of becoming a new long-term opioid user was undergoing a surgical procedure called an open thoracotomy, in which a cut is made between the ribs to see and reach the lungs, researchers said.

Post-thoracotomy pain syndrome is pain that persists months after the surgery.

Of roughly 54,500 participants in the study, 3,325 patients, about 6%, who had been newly prescribed opioids still were taking them six months after surgery for lung cancer. Of these, 859, or 1.6%, were taking potent opioids, and 2,466, or 4.5%, were taking less potent opioids.

Within two years of lung cancer surgery, 17.5%, or 574 long-term opioid users had died, compared with 9.5% of patients who were not taking opioids.

The study categorized codeine, dihydrocodeine, and tramadol as less potent opioids, while all other opioids, including fentanyl, morphine, oxycodone, hydromorphone and methadone, were designated as potent opioids.

Lung cancer patients who took less potent opioids still were 22% more likely to die than non-opioid users, and those taking more potent opioids were 92% more likely to die within two years post-surgery, the researchers said.

The study included all adults diagnosed with lung cancer who underwent surgery for it between 2011 and 2018 in South Korea, using a national database.

"This is the first study to identify the association of new long-term opioid use with poorer long-term survival outcomes after lung cancer surgery using real-world data based on a national registration database," Dr. Tak Kyu Oh, the study's lead author, and two colleagues said in the study.

Oh is assistant professor in the Department of Anesthesiology and Pain Medicine at Seoul National University Bundang Hospital in Seongnam, South Korea.

The researchers said the observational study could not establish cause, and they were unable to ascertain participants' lung health before surgery or their lifestyle behaviors, such as smoking and drinking, or how advanced their tumors were, all of which may have influenced the findings.

But they cited previous research indicating opioids may promote tumor growth and inhibit cancer cell death, while also suppressing the body's immune system.

According to the Centers for Disease Control and Prevention, lung cancer is the third most common form of the disease, after skin and breast cancers.

The CDC cited 221,097 reported new cases of lung cancer in 2019, according to the latest available data, and the disease accounted for 139,601 deaths that year.

The new study's researchers cited lung cancer as the leading cause of cancer deaths worldwide, noting that the disease accounted for 1.8 million deaths in 2020.

They noted that new, persistent postoperative pain has been reported in up to 12% of lung cancer patients, but said previous research has been confined mainly to small studies in the United States.

So, they set out to determine what proportion of lung cancer patients experiencing such pain become long-term opioid users for the first time following surgery: It was 6.1% of patients in South Korea.

They also wanted to determine whether particular factors are associated with long-term opioid use and whether lung cancer patients experienced any harmful effects from the medication within two years post-operation.

The researchers adjusted for participants' underlying conditions and disabilities, type of surgery and whether it was a repeat or first-time procedure, and whether the patient was discharged home or to a nursing facility.