Randomized Multicenter Placebo-Controlled Trial of Omega-3 Fatty Acids for the Control of Aromatase Inhibitor-Induced Musculoskeletal Pain: SWOG S0927

Hershman DL, Unger JM, Crew KD, Awad D, Dakhil SR, Gralow J, Greenlee H, Lew DL, Minasian LM, Till C, Wade JL 3rd, Meyskens FL, Moinpour CM · Journal of Clinical Oncology

Pain fell by about a third in both arms and the arms never separated. Worst-pain scores started at 7.06 and 6.88 out of 10 and fell 2.23 and 1.81 points by 24 weeks, each significant against its own baseline at p < 0.001; the adjusted 12-week between-group difference is 0.17 points in favour of omega-3 (95% CI -0.79 to 0.44, p = 0.58), with weeks 6 and 24 the same. A 2-point drop was reached by 61% on omega-3 and 57% on placebo. The stiffness, function and quality-of-life measures split — two numerically favouring omega-3, one favouring placebo, none significant. Triglycerides fell 22.1 mg/dL on omega-3 against 0.1 on placebo (p = 0.01), confirming the dose was taken and absorbed. HDL rose 2.9 mg/dL within the omega-3 arm (p = 0.007) with no difference between arms (p = 0.25), and LDL and CRP did not move. A well-powered demonstration of how large the improvement is on both sides of a joint-pain endpoint.

Population

249 evaluable women with early-stage breast cancer on an aromatase inhibitor, worst joint pain/stiffness scored at least 5 of 10 at entry, from 262 registered

Intervention

3.3 g/day omega-3 fatty acids for 24 weeks

Comparator

Soybean/corn oil placebo

Limitations

Aromatase-inhibitor arthralgia is a drug side effect, not osteoarthritis, and the comparator oil is not inert. Sixteen percent of each arm had no week-12 score. Supported by the Breast Cancer Research Foundation and the National Cancer Institute. Registered NCT01385137.