Modifying lifestyle choices can help prevent breast cancer.

Introduction

Breast cancer remains the most common cancer among Australian women, accounting for 27% of all cancers diagnosed in 2007¹ and is the second most common cause of cancer-related death.² 

Due to the increasing incidence, significant morbidity and mortality, breast cancer risk-reduction strategies remain a national health priority.^3,4

Weight gain and obesity

The strongest current evidence for the primary prevention of cancer and for improving outcomes after diagnosis of cancer relate to achieving and maintaining a healthy weight. 

Pre-diagnosis:

There is consistent high-quality evidence that being overweight or obese is an independent risk factor for breast cancer, with data suggesting that women with a BMI of ≥ 28 kg/m2 have a 26% greater relative risk of cancer compared to lean women.^{5, 6}

Obesity is also an independent prognostic factor for development of distant metastases, with 46% increased relative risk after 10 years in those with a BMI ≥ 30 kg/m2 at diagnosis.

Central adiposity and obesity at diagnosis are important modifiable risk factors for breast cancer recurrence, all-cause mortality and comorbid conditions.^7,8

Post-diagnosis: 

Weight gain following diagnosis of breast cancer is common, with 50–96% of early-stage breast cancer patients experiencing weight gain (ranging from 1.7–5.0 kg).⁹ 

Risk factors for weight gain appear to be adjuvant chemotherapy, tamoxifen use, decreased physical activity, younger age and premenopausal status at diagnosis.¹⁰ 

In addition, the fatigue and psychological distress that frequently accompany treatment may impact on lifestyle-related behaviours.²

Importantly, the beneficial effects of chemotherapy and adjuvant hormone therapy seem to be lost more rapidly in obese patents with breast cancer.¹¹ 

Weight gain is linked to endocrine and metabolic disturbances that may contribute to the poorer prognosis of women with breast cancer.

Hyperinsulinaemia and insulin resistance that underpin type 2 diabetes have been associated with poorer breast cancer outcome in observational studies.¹² Maintenance of a healthy weight throughout the lifespan and the prevention of further weight gain post diagnosis of breast cancer is therefore a priority.⁶

 Alcohol

Consumption of alcohol, even at moderate levels and regardless of beverage type, has been shown to increase breast cancer risk at all ages.¹³ The effects of alcohol may be mediated by pro-carcinogenic pathways, and nutrient deficiencies including folate.^14,3

 Nutrition

The role of diet in breast cancer prevention and outcomes appears conflicting, with further research required. 

To date, there is no robust evidence suggesting individual foods such as soy products, caffeine, red meat, dairy products and dietary fat increases the risk of breast cancer.^{3, 4} 

Limited evidence suggests a potential protective effect with increased fruit, vegetable and wholegrain consumption.^14-16 

The use of antioxidant supplements such as vitamin C, beta-carotenoids and vitamin E also have minimal protective benefits.^4,17,18

Cancer is an area in which a multitude of dietary approaches, nutrients and complementary therapies are currently being studied; however, current evidence does not support the specific inclusion of any particular food, nutrient or supplement. 

Nutrition recommendations should therefore promote a healthy well-balanced diet.⁴

Vitamin d supplementation

Inverse relationships have been reported between serum vitamin D levels and breast cancer development, recurrence and mortality.¹⁹ 

Epidemiological studies in women with breast cancer show approximately 75% of women with newly diagnosed breast cancer are vitamin D deficient.²⁰ 

Adequate vitamin D, essential for bone health, is also important, as many women with breast cancer are at risk of osteoporosis either due to early menopause or bone loss associated with aromatase inhibitors.²¹ 

Exercise

Consistent evidence indicates moderate physical activity, at around 200 minutes per week, reduces the risk of breast cancer diagnosis and recurrence.^22,23 

Exercise is an effective intervention to improve quality of life, cardiorespiratory fitness, physical functioning and fatigue in breast cancer patients and survivors.²⁴

Moreover, there is consistent findings showing a protective effect of regular physical activity and all-cause mortality among breast cancer survivors.^25

Lifestyle and breast cancer risk317.35 KB

References

1. Cancer in Australia: an overview, 2010. Cancer series no. 60. Cat. no. CAN 56. . Australian Institute of Health and Welfare & Australasian Association of Cancer Registries. Canberra: AIHW; 2010.

2. Nawroth F, Foth D, Stute P, Schmidt T, Romer T. Possibilities of sterility therapy in a patient with a premature menopause due to an X-chromosomal anomaly - a case report. Maturitas37(2):129-32. 2000.

3. Mahoney MC, Bevers T, Linos E, Willett WC. Opportunities and strategies for breast cancer prevention through risk reduction. CA Cancer J Clin. 2008 Nov-Dec;58(6):347-71.

4. Michels KB, Mohllajee AP, Roset-Bahmanyar E, Beehler GP, Moysich KB. Diet and breast cancer: a review of the prospective observational studies. Cancer. 2007 Jun 15;109(12 Suppl):2712-49.

5. Lahmann PH, Lissner L, Gullberg B, Berglund G. A prospective study of adiposity and all-cause mortality: the Malmo Diet and Cancer Study. Obes Res. 2002 May;10(5):361-9.

6. Vance V, Mourtzakis M, McCargar L, Hanning R. Weight gain in breast cancer survivors: Prevalence, pattern and health consequences. Obesity Reviews. 2011;12(4):282-94.

7. Friedenreich CM. Review of anthropometric factors and breast cancer risk. Eur J Cancer Prev. 2001 Feb;10(1):15-32.

8. Ryu SY, Kim CB, Nam CM, Park JK, Kim KS, Park J, et al. Is body mass index the prognostic factor in breast cancer?: a meta-analysis. J Korean Med Sci. 2001 Oct;16(5):610-4.

9. Demark-Wahnefried W, Peterson BL, Winer EP, Marks L, Aziz N, Marcom PK, et al. Changes in weight, body composition, and factors influencing energy balance among premenopausal breast cancer patients receiving adjuvant chemotherapy. J Clin Oncol. 2001 May 1;19(9):2381-9.

10. Nissen MJ, Shapiro A, Swenson K. Changes in weight and body composition in women receiving chemotherapy for breast cancer. Clinical Breast Cancer. 2011;11(1):52-60.

11. Ewertz M, Jensen MB, Gunnarsdottir KA, Hojris I, Jakobsen EH, Nielsen D, et al. Effect of obesity on prognosis after early-stage breast cancer. J Clin Oncol. 2011 Jan 1;29(1):25-31.

12. Adler NE, Stewart J. Reducing obesity: motivating action while not blaming the victim. Milbank Q. 2009 Mar;87(1):49-70.

13. Chen WY, Rosner B, Hankinson SE, Colditz GA, Willett WC. Moderate Alcohol Consumption During Adult Life, Drinking Patterns, and Breast Cancer Risk. JAMA: The Journal of the American Medical Association. 2011 November 2, 2011;306(17):1884-90.

14. Holmes MD, Stampfer MJ, Colditz GA, Rosner B, Hunter DJ, Willett WC. Dietary factors and the survival of women with breast carcinoma. Cancer. 1999;86(5):826-35.

15. Kwan ML, Weltzien E, Kushi LH, Castillo A, Slattery ML, Caan BJ. Dietary Patterns and Breast Cancer Recurrence and Survival Among Women With Early-Stage Breast Cancer. Journal of Clinical Oncology. 2009 February 20, 2009;27(6):919-26.

16. Pierce JP, Natarajan L, Caan BJ, Parker BA, Greenberg ER, Flatt SW, et al. Influence of a Diet Very High in Vegetables, Fruit, and Fiber and Low in Fat on Prognosis Following Treatment for Breast Cancer. JAMA: The Journal of the American Medical Association. 2007 July 18, 2007;298(3):289-98.

17. Coulter ID, Hardy ML, Morton SC, Hilton LG, Tu W, Valentine D, et al. Antioxidants vitamin C and vitamin e for the prevention and treatment of cancer. J Gen Intern Med. 2006 Jul;21(7):735-44.

18. Graham S, Zielezny M, Marshall J, Priore R, Freudenheim J, Brasure J, et al. Diet in the epidemiology of postmenopausal breast cancer in the New York State Cohort. Am J Epidemiol. 1992 Dec 1;136(11):1327-37.

19. Goodwin PJ, Ennis M, Pritchard KI, Koo J, Hood N. Prognostic effects of 25-hydroxyvitamin D levels in early breast cancer. J Clin Oncol. 2009 Aug 10;27(23):3757-63.

20. Goodwin P. Vitamin D in cancer patients: above all do no harm. Journal of Clinical Oncology. 2009;27(13):2117-9.

21. Holick MF, Binkley NC, Bischoff-Ferrari HA, Gordon CM, Hanley DA, Heaney RP, et al. Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2011 Jul;96(7):1911-30.

22. Thune I, Brenn T, Lund E, Gaard M. Physical activity and the risk of breast cancer. N Engl J Med. 1997 May 1;336(18):1269-75.

23. Verloop J, Rookus MA, van der Kooy K, van Leeuwen FE. Physical activity and breast cancer risk in women aged 20-54 years. J Natl Cancer Inst. 2000 Jan 19;92(2):128-35.

24. McNeely ML, Campbell KL, Rowe BH, Klassen TP, Mackey JR, Courneya KS, et al. Effects of exercise on breast cancer patients and survivors: a systematic review and meta-analysis. CMAJ Canadian Medical Association Journal. [Meta-Analysis Research Support, Non-U.S. Gov't]. 2006 Jul 4;175(1):34-41.

25. Sternfeld B, Weltzien E, Quesenberry CP, Castillo AL, Kwan M, Slattery ML, et al. Physical Activity and Risk of Recurrence and Mortality in Breast Cancer Survivors: Findings from the LACE Study. Cancer Epidemiology Biomarkers & Prevention. 2009 January 1, 2009;18(1):87-95.

Content Updated 2 December, 2011