title: A systematic review and meta-analysis of the n-3 polyunsaturated fatty acids effects on inflammatory markers in colorectal cancer.
abstract: BACKGROUND
  Cancer and inflammation are closely related and an exacerbated inflammatory process can lead to tumor progression and a worse prognosis for the patient with cancer. Scientific literature has shown evidence that n-3 polyunsaturated fatty acids (PUFA) have anti-inflammatory action, and for this reason could be useful as an adjuvant in the treatment of some cancers.
  
  
  OBJECTIVE
  A systematic review and meta-analysis of the literature was conducted until September, 2014, to evaluate the effects of n-3 PUFA on inflammatory mediators in colorectal cancer (CRC) patients.
  
  
  METHODS
  Clinical trials were systematically searched in three electronic databases and screening reference lists. Random meta-analysis model was used to calculate the overall and stratified effect sizes.
  
  
  RESULTS
  Nine trials, representing 475 patients with CRC, evaluated effects of n-3 PUFA on cytokines (n = 6) and/or acute phase proteins (n = 5) levels. n-3 PUFA reduce the levels of IL-6 (SMD -2.34; 95% CI -4.37, -0.31; p = 0.024) and increase albumin (SMD 0.31; 95% CI 0.06, 0.56; p = 0.014) in overall analyses. In stratified analyses, reduction in IL-6 levels occurs in surgical patients that received 0.2 g/kg of fish oil parenterally at postoperative period (SMD -0.65; 95% CI -1.06, -0.24; p = 0.002), while, increase in albumin concentration occurs in surgical patients that received ≥ 2.5 g/d of EPA + DHA orally at preoperative period (SMD 0.34; 95% CI 0.02, 0.66; p = 0.038). In patients undergoing chemotherapy, the supplementation of 0.6 g/d of EPA + DHA during 9 week reduces CRP levels (SMD -0.95; 95% CI -1.73, -0.17; p = 0.017), and CRP/albumin ratio (SMD -0.95; 95% CI -1.73, -0.18; p = 0.016).
  
  
  CONCLUSIONS
  The results suggest benefits on some inflammatory mediators with the use of n-3 PUFA on CRC patients, but these benefits are specific to certain supplementation protocols involving duration, dose and route of administration, and also, the concomitant anti-cancer treatment adopted.
authors.affiliation: Department of Nutrition, Graduate Program in Nutrition, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil.
authors.forename: Michel C
authors.initials: MC
authors.lastname: Mocellin
authors.affiliation: Department of Nutrition, Graduate Program in Nutrition, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil.
authors.forename: Carolina Q
authors.initials: CQ
authors.lastname: Camargo
authors.affiliation: Departament of Physiology, Laboratory of Investigation in Chronic Diseases, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil.
authors.forename: Everson Araujo
authors.initials: EA
authors.lastname: Nunes
authors.affiliation: Department of Nutrition, Graduate Program in Nutrition, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil.
authors.forename: Giovanna M R
authors.initials: GMR
authors.lastname: Fiates
authors.affiliation: Department of Nutrition, Graduate Program in Nutrition, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil. Electronic address: erasmotrindade@gmail.com.
authors.forename: Erasmo B S M
authors.initials: EBSM
authors.lastname: Trindade
mesh_terms: D015415:Biomarkers / Q000097:blood*; D002097:C-Reactive Protein / Q000378:metabolism; D015179:Colorectal Neoplasms / Q000097:blood* / Q000188:drug therapy; D019587:Dietary Supplements; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage* / Q000097:blood; D005395:Fish Oils / Q000008:administration & dosage; D006801:Humans; D007249:Inflammation / Q000097:blood* / Q000188:drug therapy; D053583:Interleukin-1beta / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D016032:Randomized Controlled Trials as Topic; D015203:Reproducibility of Results; D012709:Serum Albumin / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D015415:Biomarkers; D015525:Fatty Acids, Omega-3; D005395:Fish Oils; C508585:IL1B protein, human; C508600:IL6 protein, human; D053583:Interleukin-1beta; D015850:Interleukin-6; D012709:Serum Albumin; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein
keywords: Colorectal cancer; Inflammation; Inflammatory markers; Meta-analysis; Systematic review; n-3 polyunsaturated fatty acids