[vannevar]

The study in question does not link fish oil supplements to cancer. It correlates (with no clear evidence of causality) high blood levels of fatty acids with actual cases of prostate cancer. It is speculated that for at least some of the subjects, the high levels of fatty acids may have come from supplements.

FTA: "It is worth bearing in mind that this study did not assess participants’ diet and use of supplements. Researchers measured blood levels of fatty acids and analysed the association with prostate cancer risk. However, it is likely that the very high levels of fatty acids found in some participants’ blood came from supplements."