How plausible is the use of dietary ω-3 PUFA in the adjuvant therapy of cancer?

Considerable debate exists regarding the potential antineoplastic effect of long-chain dietary ω-3 polyunsaturated fatty acids (LC-ω-3 PUFA) contained in fat fishes. Since the majority of published data has proven that their intake does not induce toxic or carcinogenic effects in humans, their possible preventive use against cancer has been suggested. On the other hand, it is very hard to imagine that they could be administered to cancer patients as a single therapy. Nevertheless, a considerable effort has been put forth in recent years to evaluate the hypothesis that ω-3 PUFA might improve the antineoplastic efficiency of the currently used anticancer agents. The rationale for this therapeutic combinatory strategy is trying to increase the cancer sensitivity to conventional therapies. This could allow the use of lower drug/radiation doses and, thereby, the reduction of the detrimental health effects associated to these treatments. We will here critically examine the studies that have investigated this possibility, by focusing particularly on the biological and molecular mechanisms underlying the antineoplastic effect of these combined treatments. A possible use of ω-3 PUFA in combination with the innovative single-targeted anti-cancer therapies, that often are not completely devoid of dangerous side-effects, is also suggested.