Omega-3 Fatty Acid in Treating Pain in Patients With Breast or Ovarian Cancer Receiving Paclitaxel

Overview

Paclitaxel, a widely used chemotherapeutic agent, is associated with several well-known side effects including neuropathy (weakness, numbness and pain) and generalized body aches. The latter has recently been described as paclitaxel-associated acute pain syndrome (P-APS) and often occurs in the first three to four days after administration. It affects about 58-90% of patients. Currently, the mechanism of P-APS is unknown, and there is no standard of care to treat it. However, an intervention with both anti-inflammatory as well as neuroprotective properties would be an ideal candidate for testing in the prevention of P-APS and subsequent development of peripheral neuropathy. Previous studies have suggested that omega-3 fatty acids may act as neuroprotective agents, and there are no currently documented safety concerns with their combined use with paclitaxel. Therefore, this randomized pilot clinical trial will determine whether omega-3 fatty acids can treat pain in patients with breast or ovarian cancer receiving paclitaxel.

One mechanism proposed for P-APS is an early inflammatory process characterized by macrophage activation in both the dorsal root ganglia and peripheral nerve occurring shortly after paclitaxel therapy. Morphologic alterations in DRG satellite cells have been noted and upregulation of proinflammatory cytokines have been hypothesized as early events in the development of neuropathy. Therefore, it is possible that paclitaxel-induced neuropathic pain may be mediated by pro-inflammatory cytokines. If P-APS and chronic neuropathy are indeed part of a continuum, the inflammatory pathway would be a reasonable target for therapy. While the mechanism of how paclitaxel leads to the development of neuropathy is still not understood, it has been hypothesized that its microtubule-stabilizing effects disrupt axonal transport. Intervention with an agent that is both anti-inflammatory as well as neuroprotective is therefore worth exploring. Long chain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are common dietary supplements. They have well established anti-inflammatory properties which serve as the basis for their use in therapeutic trials in inflammatory conditions. Omega -3 fatty acids consumption can attenuate the production of pro-inflammatory metabolites. In addition, it can generate local mediators that facilitate resolution of inflammation. Thus, if P-APS is indeed mediated by inflammation, the anti-inflammatory activity of omega 3 fatty acids may be one mechanism to prevent P-APS. Additionally, given its well established safety profile, it may be an attractive alternative to NSAIDS. A dose of at least 2.7 g/day of EPA and DHA have been reported to have analgesic effects in inflammatory conditions. The dose of 4 g/day is an FDA-approved dose of omega 3 fatty acids (Lovaza) for the treatment of hypertriglyceridemia and has a well-documented toxicity profile. On the basis of this, a dose of 4 g/day was selected for this study. Lovaza (omega-3-acid ethyl esters) capsules will be used. Each 1-gram capsule contains approximately 465 mg EPA and 375 mg DHA.