New-onset persistent opioid use following breast cancer treatment in older adult women.

Persistent opioid use was an infrequent occurrence among older adult patients with breast cancer completing cancer treatment between 2008 and 2013. This finding was encouraging because of the concerning opioid trends seen in noncancer populations. However, opportunities to further mitigate unsafe opioid use as a complication of cancer care, including standardization of persistent opioid use definitions, should be explored.