Omega-3 Fatty Acids and Placebo Reduce Aromatase Inhibitor–Related Musculoskeletal Pain in Early Breast Cancer


Key Points

  • Arthralgia was reduced with both omega-3 fatty acids and placebo.
  • Similar proportions of patients in each group had clinically significant reductions.

In the SWOG S0927 trial reported in the Journal of Clinical Oncology, Hershman et al found that both omega-3 fatty acids and placebo resulted in marked persistent reductions in aromatase inhibitor–related arthralgia among patients with early breast cancer, with no difference between treatments observed.

Study Details

In the double-blind trial, 249 evaluable patients with stage I to III breast cancer receiving adjuvant aromatase inhibitor therapy for ≥ 90 days who had a worst joint pain/stiffness score ≥ 5 of 10 on the Brief Pain Inventory–Short Form (BPI-SF) were randomly assigned to receive omega-3 fatty acids 3.3 g (n = 122) or placebo (soybean/corn oil; n = 127) daily for 24 weeks. Symptoms had to have started or worsened while on aromatase inhibitor therapy.

Clinically significant improvement was defined as a ≥ 2 point decrease in BPI-SF worst pain/stiffness score from baseline. The primary outcome measure was change in worst pain/stiffness score at 12 weeks.

Similar Improvements

The mean observed BPI-SF worst pain/stiffness score decreased from baseline by 1.74 points in the omega-3 fatty acid group vs 1.49 points in the placebo group at week 12 and by 2.22 vs 1.81 points at 24 weeks. In multivariate analysis adjusting for baseline score, osteoarthritis, and taxane use, there were no differences between groups in scores at 12 weeks (P = .58) or 24 weeks (P = .34).

A 2-point reduction from baseline score was observed in 61% of women in the omega-3 fatty acid group and 57% of those in the placebo group. Similar results were observed with regard to BPI-SF pain interference scores and global rating of change in joint pain and joint stiffness scales.

Triglyceride Reduction

Triglyceride levels were elevated (≥150 mg/dL) in 38% of the omega-3 fatty acid group and 34% of the placebo group at baseline. Triglycerides were reduced by 22.1 mg/dL in the omega-3 fatty acid group and did not change in the placebo group (P < .01). No between-group differences were seen in other lipid measures or in C-reactive protein levels.

The investigators concluded: “We found a substantial (> 50%) and sustained improvement in [aromatase inhibitor] arthralgia for both [omega-3 fatty acids] and placebo but found no meaningful difference between the groups.”

Dawn L. Hershman, MD, of Columbia University Medical Center, is the corresponding author for the Journal of Clinical Oncology article.

The study was supported by the Breast Cancer Research Foundation, National Cancer Institute (NCI) Division of Cancer Prevention, and NCI Community Oncology Research Program. For full disclosures of the study authors, visit

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.