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Opioid use in breast cancer patients linked to treatment nonadherence

Breast cancer patients who use opioids to manage their pain are significantly less likely to adhere to vital adjuvant endocrine therapies and are at a significantly increased risk for death, according to findings published in Breast Cancer Research and Treatment.

“Pain is an important area of focus and intervention in breast cancer survivorship care, mainly due to its high prevalence, long persistence and negative impacts on patients’ quality of life. ... Adjuvant endocrine therapy (AET), including both [aromatase inhibitors (AI)] and [tamoxifen (TAM)], plays a critical role in improved breast cancer survival,” Rajesh Balkrishnan, PhD, from the University of Virginia School of Medicine, and colleagues wrote.

However, “there has been limited population-based research regarding the use of opioids in U.S. breast cancer survivors treated with AET,” they added.

Balkrishnan and colleagues sought to determine factors linked to opioid use, how opioid use differed across AET regimens and how opioid use affected overall survival in breast cancer patients treated with AET. They recruited 10,773 women (mean age, 72.3 years) with incident, primary, hormone-receptor-positive, stage I to III breast cancer who were first-time AET users and fee-for-service Medicare enrollees from the 2006 to 2012 SEER-Medicare datasets. Participants were followed for at least 2 years after the first date they filled an AET prescription, and researchers measured whether they used opioids during this period.

When adjusting for inverse probability treatment weights and unbalanced covariates, the researchers found that participants who used aromatase inhibitors only had a similar average treatment effect probability of opioid use compared with those who used tamoxifen only (aromatase inhibitors, 56.2% vs. tamoxifen, 55.3%). Opioid use was more likely in participants who switched AET regimens from aromatase inhibitors to tamoxifen compared with those who used aromatase inhibitors only and tamoxifen only.

In addition, there was a significant association between opioid use and AET nonadherence. Risk for death was significantly higher in participants who were opioid users (adjusted HR = 1.59; P < .001). Opioid use was most common in women who were younger, single, had more advanced cancer and had been diagnosed with depression.

“Our study found that elderly breast cancer survivors are at elevated risk of non-de-escalation of opioid treatments to manage musculoskeletal pain associated with use of AETs,” Balkrishnan told Healio Internal Medicine. “Our findings also show that patients with prolonged opioid use have reduced adherence to recommended adjuvant hormone treatments, and in turn poorer survival.”

“These findings highlight the importance of safe and effective use of pharmacological pain treatments in this very vulnerable population,” he continued. “Cancer pain is very real and sometimes needs strong pharmacological treatments like opioids to be controlled. However, if these agents are used, there is a need for proper de-escalation because of the high abuse and tolerance issues associated with them.” – by Alaina Tedesco

Disclosure: The authors report no relevant financial disclosures.