Breast Cancer: Survival and Prevention
As long ago as 1982, the National Research Council published a report called Diet, Nutrition, and Cancer, 24 showing the evidence already available linking specific dietary factors to cancer of the breast and other organs.
Asian countries, such as Japan, have low rates of breast cancer, while Western countries have cancer rates that are many times higher. 25,26 However, when Japanese girls are raised on westernized diets, their rate of breast cancer increases dramatically.
The traditional Japanese diet is much lower in fat, especially animal fat, than the typical Western diet. In the late 1940s, when breast cancer was particularly rare, less than 10 percent of the calories in the Japanese diet came from fat. 27 The American diet, of course, is centered on animal products, which tend to be high in fat and low in other important nutrients. The fat content of the average American diet is in the range of 37 to 40 percent of calories.
Countries with a higher intake of fat, especially animal fat, have a higher incidence of breast cancer. 25,28,29 Even within Japan, affluent women who eat meat daily have an 8.5 times higher risk of breast cancer than poorer women who rarely or never eat meat. 26 The Surgeon General's Report on Nutrition and Health 30 stated: "Indeed, a comparison of populations indicates that death rates for cancers of the breast, colon, and prostate are directly proportional to estimated dietary fat intakes."
Surviving Breast Cancer
Not all cancers are the same. Some have a relatively good prognosis, and others have a very poor prognosis. For example, a tumor that is small and has not spread to the lymph nodes or other organs is less dangerous than a tumor that is larger and has already spread. (Lymph nodes are pea-sized collections of cells near the breast and other organs which are important to immune function.) Hospital laboratories also determine whether a breast tumor has receptors for estrogen or progesterone hormones. If it does, the tumor is slightly less aggressive than if it lacks receptors.
These prognostic factors are not due to chance alone. Thirty years ago, Ernst Wynder of the American Health Foundation in New York observed that, aside from the fact that Japanese women are much less likely than American women to get breast cancer, when Japanese women do get the disease, they tend to survive longer. 79 Their improved survival is independent of age, tumor size, estrogen receptor status, the extent of spread to lymph nodes, and the microscopic appearance of the cancer cells. 80 And it is not that Japanese women have better health care, because the same pattern has been observed in Hawaii 81 and California, 82 where Japanese women live nearby other ethnic groups, and have essentially the same health care system.
Researchers have begun to look at whether diet plays a role in survival. It does. Our old enemy, fat in foods, rears its ugly head once again. The more fat there is in the diet, the shorter a cancer patient survives. In a Canadian research study, women with cancer were more likely to have lymph node involvement if they had a higher fat intake. This effect was found only for saturated fat and only for post-menopausal women. 83 Fat seems to have a measurable effect when cancer has spread to other parts of the body, and little or no effect when the disease is localized. 84
Researchers in Buffalo, New York, calculated what they believe to be the degree of risk posed by fat in the diet: for a woman with metastatic breast cancer (cancer which has already spread at the time of diagnosis), her risk of dying from the disease at any point in time increases 40 percent for every 1,000 grams of fat consumed monthly. 80 In order to understand what this means, compare three different diets, each of which contains 1,200 calories per day:
- On a low-fat, vegetarian diet , about 10 percent of calories come from fat. This type of diet contributes about 13 grams of fat per day, or 400 grams per month.
- On a typical American diet , 37 percent of calories come from fat. This means about 49 grams of fat per day, or 1,380 grams per month.
- On a diet with more fat than average , say 50 percent of calories, fat intake would be 67 grams per day, or 2,000 grams per month.
If the researchers' finding holds, the typical American diet would lead to about a 40 percent higher risk of dying of breast cancer at any given point, compared to the low-fat, vegetarian diet, and the high-fat diet would lead to a more than 60 percent increase in risk of dying. These figures do not mean that a woman's risk of dying is 40 percent or 60 percent. They mean that the risk is 40 percent or 60 percent higher than it would otherwise have been, assuming the individual is comparable to those studied.
Other parts of the diet play important roles. Diets that are high in fiber, carbohydrate, and vitamin A seem to help the prognosis, while alcohol slightly worsens it. 85 Patients who have more estrogen receptors on their tumors (which indicates a better prognosis) tend to be those who had consumed more vitamin A. 85 (Beta-carotene becomes vitamin A in the body.) For reasons that are not entirely clear, vegetables and fruits, and the vitamins they contain, help keep the cells of the body in better working order—one sign of which, for breast cells, is the presence of estrogen receptors. So vegetables and fruits are not only important in helping to prevent cancer, but also in improving survival for those who have cancer.
Higher body weight increases the risk of dying of breast cancer. 84,86 Among postmenopausal women with breast cancer, slimmer women tend to have less lymph node involvement. 87 Heavier women have more lymph node involvement, higher rates of recurrence, and poorer survival. 83
24. National Research Council. Diet, Nutrition, and Cancer. Washington, DC: National Academy Press, 1982.
25. Armstrong B, Doll R. Environmental factors and cancer incidence and mortality in different countries, with special reference to dietary practices. Int J Cancer 1975;15:617-31.
26. Hirayama T. Epidemiology of breast cancer with special reference to the role of diet. Prev Med 1978;7:173-95.
27. Lands WEM, Hamazaki T, Yamazaki K, et al. Changing dietary patterns. Am J Clin Nutr 1990;51:991-3.
28. Carroll KK, Braden LM. Dietary fat and mammary carcinogenesis. Nutrition and Cancer 1985;6:254-9.
29. Rose DP, Boyar AP, Wynder EL. International comparisons of mortality rates for cancer of the breast, ovary, prostate, and colon, and per capita food consumption. Cancer 1986;58:2363-71.
30. U.S. Department of Health and Human Services. Surgeon General's Report on Nutrition and Health. DHHS Publ No. 88-50210, 1988.
31. Rose DP, Boyar AP, Cohen C, Strong LE. Effect of a low-fat diet on hormone levels in women with cystic breast disease. 1. Serum steroids and gonadotropins. J Natl Cancer Inst 1987;78(4):623-6.
32. Ingram DM, Bennett FC, Willcox D, de Klerk N. Effect of low-fat diet on female sex hormone levels. J Natl Cancer Inst 1987;79:1225-9.
33. Goldin BR, Gorbach SL. Effect of diet on the plasma levels, metabolism and excretion of estrogens. Am J Clin Nutr 1988;48:787-90.
34. Toniolo P, Riboli E, Protta F, Charrel M, Cappa AP. Calorie-providing nutrients and risk of breast cancer. J Natl Cancer Inst 1989;81:278.
35. Messina MJ, Barnes S. The role of soy products in reducing risk of cancer. J Natl Cancer Inst 1991;83:541-6.
36. Willet WC. Dietary fat and risk of breast cancer. N Engl J Med 1987a;316:22-8.
37. Robbana-Barnat S, Rabache M, Rialland E, Fradin J. Heterocyclic amines: occurrence and prevention in cooked food. Environ Health Perspect 1996;104:280-8.
38. Thiebaud HP, Knize MG, Kuzmicky PA, Hsieh DP, Felton JS. Airborne mutagens produced by frying beef, pork, and a soy-based food. Food Chem Toxicol 1995;33(10):821-8.
39. De Stefani E, Ronco A, Mendilaharsu M, Guidobono M, Deneo-Pellegrini H. Meat intake, heterocyclic amines, and risk of breast cancer: a case-control study in Uruguay. Cancer Epidemiol Biomarkers Prev 1997;6(8):573-81.
40. Matos EL, Thomas DB, Sobel N, Vuoto D. Breast cancer in Argentina: case-control study with special reference to meat eating habits. Neoplasma 1991;38(3):357-66.
41. Howe GR, Hirohata T, Hislop T, et al. Dietary factors and risk of breast cancer: combined analysis of 12 case-control studies. J Natl Cancer Inst 1990;82:561-9.
42. Willett WC, Polk BF, Morris MJ, et al. Prediagnostic serum selenium levels and risk of cancer. Lancet 1983;2:130-4.
43. Willett WC, Stampfer MJ, Colditz FA, et al. Moderate alcohol consumption and the risk of breast cancer. N Engl J Med 1987;316:1174-80.
44. Miller DR, Rosenberg L, Kaufman DW, et al. Breast cancer before age 45 and oral contraceptive use: new findings. Am J Epidemiol 1989;129:269.
45. Bergkvist L, Adami AO, Persson I, et al. The risk of breast cancer after estrogen and estrogen-progestin replacement. New Engl J Med 1989;321:293.
46. Lubin F, Ruder AM, Wax Y, Modan B. Overweight and changes in weight throughout adult life in breast cancer etiology. Am J Epidemiol 1985;122:579-88.
47. Miller FA, Hempelmann LH, Dutton AM, Pifer JW, Toyooka ET, Ames WR. Breast neoplasms in women treated with X rays for acute postpartum mastitis. A pilot study. J Natl Cancer Inst 1969;43:803-11.
48. Lynch HT, Albano WA, Heieck JJ, et al. Genetics, biomarkers, and control of breast cancer: a review. Cancer, Genetics, and Cytogenetics 1984;13:43-92.
49. Goldman BA. The Truth about Where You Live. New York: Random House, 1991.
50. Noren K. Levels of organochlorine contaminants in human milk in relation to the dietary habits of the mothers. Acta Paediatr Scand 1983;72:811-6.
51. Hergenrather J, Hlady G, Wallace B, Savage E. Pollutants in breast milk of vegetarians. Lancet 1981;304:792.
52. Wynder EL, Escher GC, Mantel N. An epidemiological investigation of cancer of the endometrium. Cancer 1966;19:489-520.
53. Elwood JM, Cole P, Rothman KJ, Kaplan SD. Epidemiology of endometrial cancer. J Natl Cancer Inst 1977;59:1055-60.
54. Lingeman CH. Etiology of cancer of the human ovary: a review. J Natl Cancer Inst 1974;53:1603-18.
55. Cramer DW, Willett WC, Bell DA, et al. Galactose consumption and metabolism in relation to the risk of ovarian cancer. Lancet 1989;2:66-71.
56. Breslow N, Chan CW, Dhom G, et al. Latent carcinoma of prostate at autopsy in seven areas. Int J Cancer 1977;20:680-8.
57. Carter BS, Carter HB, Isaacs JT. Epidemiologic evidence regarding predisposing factors to prostate cancer. Prostate 1990;16:187-97.
58. Howell MA. Factor analysis of international cancer mortality data and per capita food consumption. Br J Cancer 1974;29:328-36.
59. Blair A, Fraumeni JF, Jr. Geographic patterns of prostate cancer in the United States. J Natl Cancer Inst 1978;61:1379-84.
60. Kolonel LN, Hankin JH, Lee J, Chu SY, Nomura AMY, Hinds MW. Nutrient intakes in relation to cancer incidence in Hawaii. Br J Cancer 1981;44:332-9.
61. Rotkin ID. Studies in the epidemiology of prostatic cancer: expanded sampling. Cancer Treat Rep 1977;61:173-80.
62. Schuman LM, Mandel JS, Radke A, Seal U, Halberg F. Some selected features of the epidemiology of prostatic cancer: Minneapolis-St. Paul, Minnesota case control study, 1976-1979. In: Magnus K, ed. Trends in Cancer Incidence: Causes and Practical Implications. Washington, DC: Hemisphere Publishing Corp., 1982.
63. Graham S, Haughey B, Marshall J, et al. Diet in the epidemiology of carcinoma of the prostate gland. J Natl Cancer Inst 1983;70:687-92.
64. Ross RK, Shimizu H, Paganini-Hill A, Honda G, Henderson BE. Case-control studies of prostate cancer in blacks and whites in Southern California. J Natl Cancer Inst 1987;78:869-74.
65. Severson RK, Nomura AM, Grove JS, Stemmermann GN. A prospective study of demographics, diet, and prostate cancer among men of Japanese ancestry in Hawaii. Cancer Research 1989;49:1857-60.
66. Oishi K, Okada K, Yoshida O, et al. A case control study of prostatic cancer with reference to dietary habits. Prostate 1988;12:179-90.
67. Mettlin C, Selenskas S, Natarajan N, Huben R. Beta-carotene and animal fats and their relationship to prostate cancer risk: a case-control study. Cancer 1989;64:605-12.
68. Chan JM, Stampfer MJ, Giovannucci E, et al. Plasma insulin-like growth factor-I and prostate cancer risk: a prospective study. Science 1998;279:563-5.
69. Hirayama T. Changing patterns of cancer in Japan with special reference to the decrease in stomach cancer mortality. In: Hiatt HH, Watson JD, Winsten JA, eds. Origins of Human Cancer. Book A, Incidence of Cancer in Humans. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory, 1977. Pp 55-75.
70. Hirayama T. Epidemiology of prostate cancer with special reference to the role of diet. Natl Cancer Inst Monogr 1979;53:149-54.
71. Phillips RL. Role of lifestyle and dietary habits in risk of cancer among Seventh-day Adventists. Cancer Research 1975;35:3513-22.
72. Mills P, Beeson WL, Phillips RL, Fraser GE. Cohort study of diet, lifestyle, and prostate cancer in Adventist men. Cancer 1989;64:598-604.
73. Willett WC, Stampfer MJ, Colditz GA, Rosner BA, Speizer FE. Relation of meat, fat, and fiber intake to the risk of colon cancer in a prospective study among women. N Engl J Med 1990;323:1664-72.
74. Gerhardsson de Verdier M, Hagman U, Peters RK, Steineck G, Overvik E. Meat, cooking methods, and colorectal cancer: a case-referrent study in Stockholm. Int J Cancer 1991;49:520-5.
75. Singh PN, Fraser GE. Dietary risk factors for colon cancer in a low-risk population. Am J Epidemiol 1998;148(8):761-74.
76. Giovannucci E, Rimm EB, Stampfer MJ, Colditz GA, Ascherio A, Willett WC. Intake of fat, meat, and fiber in relation to risk of colon cancer. Cancer Res 1994;54(9):2390-7.
77. World Cancer Research Fund. Food, Nutrition, and the Prevention of Cancer: A Global Perspective. American Institute of Cancer Research. Washington, DC: 1997.
78. DeCosse JJ, Miller HH, Lesser ML. Effect of wheat fiber and vitamins C and E on rectal polyps in patients with familial adenomatous polyposis. J Natl Cancer Inst 1989;81:1290-7.
79. Wynder EL, Kajitani T, Kuno J, Lucas JC, Jr, DePalo A, Farrow J. A comparison of survival rates between American and Japanese patients with breast cancer. Surg Gynec Obstet 1963;117:196-200.
80. Gregorio DI, Emrich LJ, Graham S, Marshall JR, Nemoto T. Dietary fat consumption and survival among women with breast cancer. J Natl Cancer Inst 1985;75:37-41.
81. LeMarchand L, Kolonel LN, Nomura AMY. Ethnic differences in survival after diagnosis of breast cancer—Hawaii. JAMA 1985;254:2728.
82. Linden G. Letter to the editor. Int J Cancer 1973;12:543.
83. Verreault R, Brisson J, Deschenes L, Naud F, Meyer F, Belanger L. Dietary fat in relation to prognostic indicators in breast cancer. J Natl Cancer Inst 1988;80:819-25.
84. Newman SC, Miller AB, Howe CR. A study of the effect of weight and dietary fat on breast cancer survival time. Am J Epidemiol 1986;123:767-74.
85. Holm LE, Callmer E, Hjalmar ML, Lidbrink E, Nilsson B, Skoog L. Dietary habits and prognostic factors in breast cancer. J Natl Cancer Inst 1989;81:1218-23.