Send to

Choose Destination
Pharmacoepidemiol Drug Saf. 2019 May;28(5):740-753. doi: 10.1002/pds.4779. Epub 2019 Apr 3.

Risk of second breast cancer events with chronic opioid use in breast cancer survivors.

Author information

Health Research Institute, Kaiser Permanente Washington, Seattle, Washington.
Department of Pharmacy, University of Washington, Seattle, Washington.
Department of Epidemiology, University of Washington, Seattle, Washington.



Opioids may increase cancer risk and progression through multiple pathways. Our objective was to estimate the association between chronic opioid use and risk of second breast cancer events (SBCEs).


Cohort study of women greater than or equal to 18 years, diagnosed with early stage breast cancer between January 1, 1990, and December 31, 2008, and enrolled in a large health plan for 1+ years before and after (unless died) diagnosis. SBCEs were defined as evidence of recurrence or second primary breast cancer in the medical chart. Chronic opioid use was defined as 75+ days of use in any moving 90-day window after breast cancer diagnosis and varied to 150+ days in a 180-day window in a sensitivity analysis. Using Cox proportional hazards models, we estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for SBCE and components of SBCE by chronic opioid use.


Almost 10% met the criteria for chronic use and almost a third of users were taking opioids for greater than 3 years. Risk of SBCEs (HR = 1.20; 95% CI, 0.85-1.70), including second primary breast cancer (HR = 1.38; 95% CI, 0.71-2.70), was nonsignificantly higher among chronic users vs nonchronic/nonusers. The HR for recurrence was 1.14 (95% CI, 0.76-2.70). Results of the sensitivity analyses on longer opioid use does support an association with SBCE or recurrence.


This first US-based study on chronic opioid use and cancer outcomes provides some reassurance on safety. However, the question warrants further exploration in other populations and settings.


breast cancer; opioids; pharmacoepidemiology; recurrence; survivorship


Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center