The Conundrum of Omega-3 Fatty Acids in Cancer Prevention Studies: Which One? How Much? What Biomarkers?

Marine omega-3 fatty acids promote resolution of inflammation and have potential to reduce risk of obesity-related breast cancer. For prevention trials in obese women, inflammatory cytokines, aromatase, and measures of breast immune cell infiltration are logical, as are biomarkers of growth factor, adipokine, and estrogen signaling. Where best to look for marker change: in the circulation (easiest), in benign breast tissue (most relevant), or in visceral adipose (inflammation often most marked)? A null biomarker modulation trial may reflect limitations in design, source and dose of fatty acids, or biomarkers and should not lead to premature abandonment of marine omega-3 fatty acids for cancer prevention. Cancer Prev Res; 11(4); 187-90. ©2018 AACR See related article by Gucalp et al., p. 203 .