Higher Intakes of EPA/DHA Omega-3 Fatty Acids and Extended Survival Following Colon Cancer
Van Blarigan , E. L. et al., Cancer Epidemiology, Biomarkers and Prevention, in press, 2018
Dept. of Epidemiology and Biostatistics, Univ. of California, San Francisco, Calif., USA
This study followed 1,011 colon cancer patients of mixed genders and average age of 60 years (resected for stage III adenocarcinoma of the colon with no metastases) for a median period of 7 years. A food frequency questionnaire (FFQ) was used to estimate the amounts and types of various fish/seafood produce as consumed. Marine-based omega-3 fatty acid intakes (predominantly as EPA plus DHA) were assessed by nutrient compositional data of various fish/seafood from the USDA and a knowledge of omega-3 fatty acid intakes from fish oil supplementation. The primary outcome was disease-free survival – defined as time from the baseline FFQ to tumor recurrence, occurrence of a new primary colon tumor, or death from any cause, whichever came first. Recurrence-free survival was defined as time from the baseline FFQ to tumor recurrence or occurrence of a new primary colon tumor.
The results indicated that higher intakes of marine omega-3 fatty acids after the diagnosis of colon cancer were associated with longer disease-free survivals. Specifically, those patients in the top 25 % with respect to marine omega-3 intakes (median intakes of 400 mgs/day) had an event rate on follow-up of only 33.6 % as compared to 44.4 % for those in the bottom 25 % with respect to intakes (median intakes of only 90 mgs/day). Similar benefits on recurrence-free survival were also seen with the higher intakes. Individuals consuming dark meat fish at least once or more per week also exhibited better disease-free survivals as compared to those not consuming such fish.
Dr. Holub's Comments:
It is noted that this group previously reported that higher intakes of marine omega-3 fatty acids after the diagnosis of colorectal cancer (CRC) were associated with a lower risk of CRC-specific mortality (Song, M. et al., Gut, 66: 1790-1796 (2017)). Patients who consumed at least 300 mgs of such omega-3 fatty acids/day had a 41 % lower risk of CRC-specific mortality as compared to patients who consumed less than 100 mgs/day. It is noted that adult intakes in North America of EPA (eicosapentaenoic acid) plus DHA (docosahexaenoic acid) currently average 110-130 mgs/person/day which is well below the minimum targets of at least 300-400 mgs/person/day mentioned above which appear to enhance outcomes in those found to have CRC. Public health programs and patient education in the gastroenterology-cancer field should be instituted which offer nutritional advice for those with CRC including higher intakes of EPA/DHA to better manage their disease and to retard its progression.