Hershman, D.L., Unger, J.M., Crew, K.D., Awad, D., Dakhil, S. R., Gralow, J., . . . Moinpour, C.M. (2015). Randomized multicenter placebo-controlled trial of omega-3 fatty acids for the control of aromatase inhibitor-induced musculoskeletal pain: SWOG S0927. Journal of Clinical Oncology, 33, 1910–1917. 

To determine if omega 3 fatty acids can be effective in decreasing arthralgia resulting from aromatase inhibitor (AI) treatment

Patients were randomized to receive either a placebo or 3.3 g of omega 3 fatty acids daily for 24 weeks. Random assignment was stratified by prior history of arthritis and prior taxane use. Study assessments were done at baseline and at six, 12, and 24 weeks.

• N = 209  
• MEDIAN AGE = 59.2 years
• FEMALES: 100%
• KEY DISEASE CHARACTERISTICS: Patients with stage 1 and 2 hormone-sensitive breast cancer receiving adjuvant AI therapy 
• OTHER KEY SAMPLE CHARACTERISTICS: Pain score greater than 5 out of 10 associated with AI use; median of 1.2 years of AI treatment

• SITE: Multi-site  
• SETTING TYPE: Outpatient    
• LOCATION: United States

• PHASE OF CARE: Active antitumor treatment

Double-blinded, placebo-controlled, randomized trial

• Brief Pain Inventory Short Form (BPI-SF)
• Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)
• Modified Score for the Assessment and Quantification of Chronic Rheumatoid Affections of the Hand (M-SACRAH)
• Functional Assessment of Cancer Therapy (FACT) Endocrine Symptoms
• Serum lipids and C reactive protein

There were no significant differences between the groups in worst pain scores or stiffness at any study time point. The mean observed changes in other study measures showed somewhat reduced symptoms in the omega 3 arm, but these changes were not statistically significant. There were no significant changes in serum measures over time other than decreased triglycerides in those receiving the fatty acids. Over time, symptoms improved in both study groups.

This study did not show any improvements in arthralgia symptoms induced by AIs with the use of omega 3 fatty acids compared to a placebo.

There are no effective therapies for the prevention or treatment of AI-associated arthralgia. Ongoing research to determine optimal approaches to prevent or manage this symptom is necessary. These symptoms' mechanism of development is not clear, but they may have inflammatory and autoimmune components.