Three cases with familial adenomatous polyposis diagnosed as having malignant lesions in the course of a long-term trial using docosahexanoic acid (DHA)-concentrated fish oil capsules.

The inhibitory effect of n-3 polyunsaturated fatty acids on human colorectal cancer has been speculated on from epidemiological data and animal studies. We conducted a long-term trial of docosahexanoic acid (DHA)-concentrated fish oil capsules for patients in a high-risk group for colorectal cancer. During this trial, we experienced three patients with familial adenomatous polyposis (FAP) diagnosed as having malignant lesions. Three patients with FAP and two patients with multiple (more than 30) colorectal polyps were administered DHA-concentrated fish oil capsules_Hlk427554600[2.2 g of DHA and 0.6 g of eicosapentanoic acid (EPA) per day] for one or two years. Compliance with DHA-concentrated fish oil capsules was more than 90% in four patients and 61% in one patient. A marked increase or decrease in the number of polyps was not observed. Three patients with FAP developed endometrial cancer after 12 months, colon cancer after 24 months and lung cancer after 12 months, respectively. All cancers were diagnosed at an early stage and were resected curatively. We thought that the possibility of developing cancer from the long-term administration of fish oil capsules to patients with FAP needs to be investigated further, and that we should report these cases.

[1]  H. Narahara,et al.  Adverse effects of sulindac used for prevention of colorectal cancer. , 1997, Journal of the National Cancer Institute.

[2]  H. Esumi,et al.  Effect of docosahexaenoic acid on azoxymethane-induced colon carcinogenesis in rats. , 1994, Cancer letters.

[3]  T. Sugimura,et al.  Effects of docosahexaenoic acid (DHA) on intestinal polyp development in ApcΔ716 knockout mice , 1995 .

[4]  B. Rosner,et al.  The effect of fish oil on blood pressure in mild hypertensive subjects: a randomized crossover trial. , 1993, The American journal of clinical nutrition.

[5]  P. Palozza,et al.  n-3 fatty acids induce oxidative modifications in human erythrocytes depending on dose and duration of dietary supplementation. , 1996, The American journal of clinical nutrition.

[6]  W. Connor,et al.  Absorption of the n-3 eicosapentaenoic and docosahexaenoic acids as ethyl esters and triglycerides by humans. , 1991, The American journal of clinical nutrition.

[7]  E. Bergstralh,et al.  A controlled trial of fish oil in IgA nephropathy. Mayo Nephrology Collaborative Group. , 1994, The New England journal of medicine.

[8]  S. Moncada,et al.  Effects of fish oil on rectal cell proliferation, mucosal fatty acids, and prostaglandin E2 release in healthy subjects. , 1993, Gastroenterology.

[9]  H. Bussey,et al.  A randomized trial of ascorbic acid in polyposis coli , 1982, Cancer.

[10]  T. Strasser,et al.  Supplementation with n‐3 fatty acids from fish oil in chronic inflammatory bowel disease—a randomized, placebo‐controlled, double‐blind cross‐over trial , 1989, Journal of internal medicine. Supplement.

[11]  V. Hubbard,et al.  Changing dietary patterns. , 1990, The American journal of clinical nutrition.

[12]  E. Wynder.  The epidemiology of large bowel cancer. , 1975, Cancer research.

[13]  B. Reddy,et al.  Effect of restricted caloric intake on azoxymethane-induced colon tumor incidence in male F344 rats. , 1987, Cancer research.

[14]  W. Haenszel,et al.  Large-bowel cancer in Hawaiian Japanese. , 1973, Journal of the National Cancer Institute.

[15]  M. Campieri,et al.  Effect of an enteric-coated fish-oil preparation on relapses in Crohn's disease. , 1996, The New England journal of medicine.

[16]  C. Drevon,et al.  Effect of dietary supplementation with very-long-chain n-3 fatty acids in patients with psoriasis. , 1993, The New England journal of medicine.

[17]  T. Kuroishi,et al.  [Predictions of the incidence of cancer in Japan in the year 2000]. , 1988, Gan no rinsho. Japan journal of cancer clinics.

[18]  S. Sugie,et al.  Effect of different levels of omega-3 and omega-6 fatty acids on azoxymethane-induced colon carcinogenesis in F344 rats. , 1988, Cancer research.

[19]  Richard Doll,et al.  Environmental factors and cancer incidence and mortality in different countries, with special reference to dietary practices , 1975, International journal of cancer.

[20]  B. Reddy,et al.  Tumor promotion by dietary fat in azoxymethane-induced colon carcinogenesis in female F344 rats: influence of amount and source of dietary fat. , 1984, Journal of the National Cancer Institute.

[21]  R. Doll,et al.  The causes of cancer: quantitative estimates of avoidable risks of cancer in the United States today. , 1981, Journal of the National Cancer Institute.

[22]  K. Watanabe,et al.  Effect of high-fat diet on colon carcinogenesis in F344 rats treated with 1,2-dimethylhydrazine, methylazoxymethanol acetate, or methylnitrosourea. , 1977, Cancer research.

[23]  M. Anti,et al.  Effect of omega-3 fatty acids on rectal mucosal cell proliferation in subjects at risk for colon cancer. , 1992, Gastroenterology.

[24]  M. Lesser,et al.  Effect of wheat fiber and vitamins C and E on rectal polyps in patients with familial adenomatous polyposis. , 1989, Journal of the National Cancer Institute.

[25]  D. Kritchevsky,et al.  Inhibition of chemically induced mammary and colon tumor promotion by caloric restriction in rats fed increased dietary fat. , 1987, Cancer research.