8 Ways to Prevent Breast Cancer

In our previous posts we have written about the role of postmenopausal hormones as a cause of breast cancer, the value of weight loss and increasing physical activity for prevention and improved quality of life. Here we list 8 major opportunities to reduce the chances of developing breast cancer. When in life they apply can vary. Paying attention to weight and physical activity, and also alcohol across all ages will pay off.

1. Keep weight in check
Women who maintain a healthy weight throughout adulthood have a lower risk of breast cancer, especially if they are post-menopausal. One reason is that fat tissue affects different hormone levels in the body. Too much fat tissue can lead to higher hormone levels and increase the risk of cancer. Weight loss after menopause lowers risk of breast cancer. It's never too late to benefit from losing weight.

2. Be physically active
People who are physically active for at least 30 minutes a day have a lower risk of breast cancer, possibly because physical activity affects hormone levels and other growth factors in the body. Being physically active is also one of the best ways to help maintain a healthy weight. In addition, physically active people also have a lower risk of colon cancer, heart disease, diabetes and stroke.

3. Avoid too much alcohol
Women who have less than one drink a day have a lower risk of breast cancer. (One drink is a can of beer, a glass of wine, or a shot of hard liquor.) Alcohol may raise the level of some hormones in the body. High levels of certain hormones after menopause may cause cells in the breast to become cancerous.

4. Take a daily multivitamin with folate  
In general, there are no strong links between specific vitamins and the risk of breast cancer. However, in women who drink moderate amounts of alcohol, the vitamin folate (found in most multivitamins and B-complex vitamins) seems to protect against the increased risk associated with drinking alcohol.

5. Breastfeed, if possible
Women who breast feed for a total of one year or more have a lower risk of breast cancer. This is because breast feeding can cause changes in hormones and in breast tissue that help protect the cells from becoming cancerous. Women who regularly breast feed also have a lower risk of ovarian cancer. 

6. Avoid birth control pills, particularly after age 35  
Women currently on birth control pills have a higher risk of breast cancer. Yet, birth control pills can have positive and negative effects on a woman's health. If taken for at least 5 years, birth control pills can lower a woman's risk of colon cancer, uterine cancer and ovarian cancer. But while she's taking them, they raise her risk of breast cancer, heart attack and stroke.

7. Avoid postmenopausal hormones  
Post-menopausal hormones are medications that help ease the symptoms of menopause, like hot flashes and vaginal dryness.  Use over 1- 2 years, though, can increase the risk of breast cancer and other serious conditions, like heart disease. 

8. If at increased risk after menopause, consider a prescription anti-estrogen, like tamoxifen or raloxifene
Tamoxifen and raloxifene are medications prescribed for women at high risk of breast cancer. They block the effects of the hormone estrogen in breast tissue and can substantially reduce the risk of breast cancer. However, these medications also have serious side effects. They are not right for everyone and can only be prescribed by a doctor. Talk to your doctor if you have questions about your risk and whether these drugs may be right for you.


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Research Priority: Implementing What Works

Dissemination and implementation of research findings into practice is necessary to achieve a return on investment in our research enterprise and to apply research findings to improve outcomes in the broader community. In a thoughtful review of the application of discovery to prevention of cancer, Bowen and colleagues note, “Our previous 30 years have taught us that dissemination does not just happen if we wait for it. New information is often needed to make it happen. Let’s consider this a call to action to gather the new information in support of making it happen” (Bowen, Sorensen et al. 2009). The challenges in dissemination and implementation research are broad and apply far beyond health and health care systems. In fact, early examples come from other fields such as education in which research has addressed the application of new knowledge to improve outcomes in children’s learning (Huberman AM, Levinson NS et al. 1981; Crandall 1989; Huberman M 1991). This rapidly expanding field improving the speed with which we translate discoveries to broader application in the health care delivery systems still requires a more uniform understanding of the principles, methods, and applications to achieve the potential to improve outcomes in a more timely manner.

First, some question arise from the review that Bowen and colleagues (Bowen, Sorensen et al. 2009) conducted in the context of prevention science.
  • How will we gather this information?
  • Will it be applicable to our setting?
  • What methods should we use to decide what to disseminate or implement?
  • Which strategies will give us the greatest impact on population health?
  • What outcomes should be tracked to know if we are making progress?
  • How long will it take to show progress, or when will it be observed?

Moving from discovery to application brings society the full return on our collective investment in research. Given the crisis in funding of research and health services more broadly, we cannot afford the luxury of reinventing approaches developed in other fields (such as education) nor can we wait decades to apply discoveries and delay the return on investment in our research. For example, in 2010, the United States spent over $32 billion on health-related research (Office of Management and Budget 2010.). It is estimated that between 9 and 25% of this amount was expended on prevention research (Farquhar 1996; Harlan 1998)—i.e., the direct and immediate application of effective intervention strategies to benefit the public’s health (Institute of Medicine 1997). Farquhar has estimated that 10% or less of prevention research is focused on dissemination (Farquhar 1996). Despite this low priority, the NIH maintains an active program in “dissemination” research, but across all funding sources in 2002—federal and foundations—spending on health services research represented only 1.5% of biomedical research funding (Woolf 2008). As the CTSA program has fostered community based participatory research with additional growing emphasis on comparative effectiveness and systems level interventions to improve health outcomes, greater emphasis in these areas should be encouraged rather than threatened through funding cuts.

What are the outcomes for progress in dissemination and implementation of discoveries? These can be counted as more effective health services, better prevention, or in non-health settings - better schooling for our children, greater highway safety, or employment opportunities. The methods and issues may appear to differ across fields of study. Like statistics, which has a long history of development in agriculture (the leading industry of the time – Cochran wrote on meta-analysis of results from agriculture trial plots in 1937 and helped define modern approaches (Cochran 1937)), dissemination and dissemination research also grew from agriculture to guide thinking in this field (Rogers 1993). Now, with health care consuming an ever-increasing portion of national and state budgets in the developed world, methods to maximize our societal benefit must be refined and accessible to end users – and will likely be developed and refined most quickly in the context of health and wellness. In fact, data from OECD indicate that the average ratio of health expenditure to GDP has risen from 7.8% in 2000 to 9.0% in 2008, and is at 16.0% for the US and 10.4% for Canada. (OECD 2010) There is no shortage of academic research but how do we sift through studies and draw inference to disseminate and implement programs and policies more broadly?

Delay in adoption of scientific discoveries is not a new event. Penicillin was discovered by Fleming in 1928 (though others are attributed with noticing the effect of mold on bacteria in research laboratories). Use of penicillin was not implemented for more than 15 years, when an Australian Rhodes Scholar, Howard Florey, then in the Pathology Department at Oxford, evaluated penicillin in humans and with a team of scientists developed methods for mass production leading to widespread military use for infected soldiers (Bickell 1996). Only after the War did civilian use become available, first in Australia and then more broadly. The time delay from discovery to clinical application is typical of the lag we still see today. Of course, war has a long history for development of new methods in trauma surgery and other areas of clinical medicine, but our focus is broader application of scientific advances.

How can improving the methods for dissemination and implementation help us move more quickly to build on research findings and apply them to improve health? The challenge of implementation extends along the continuum from discovery of biologic phenomena to clinical application in research settings and the broader application in the population at large. A range of approaches to describing this continuum have been developed. Green and colleagues (Green, Ottoson et al. 2009) describe a leaky pipeline from research to practice. Across these approaches to defining stages of translation and application, some common themes emerge; discovery on its own does not lead to use of knowledge; evidence of impact does not lead to uptake of new strategies; and maintenance of change is often overlooked leading to regression of system level changes back to a prior state.The lag from discovery to application (implementation of effective programs and practices) may vary across disciplines. Examples from public health include the gap from perfecting the Papanicolaou test in 1943 to the establishment of screening programs in all US states in 1995, and the delay from the 1964 Surgeon General’s repot on smoking in 1964 to effective state wide tobacco control programs (Brownson and Bright 2004). Of course early applications will be in place to varying degrees before full widespread programs are implemented and sustained.

A frequently quoted statement about the total attrition in the funnel and the lapse between research and medical practice indicates that it takes 17 years to turn 14% of original research to the benefit of patient care, and is attributed to Balas & Boren (Balas and Boren 2000). The leakage or loss of medical-clinical research from the pipeline at each stage from completed research through submission, publication, indexing, and systematic reviews that produce guidelines and textbook recommendations for best practices, to the ultimate implementation of those practices in health care settings all contribute to these estimates. Changing technologies and priorities of publishing, bibliographic data management, and systematic reviews and disseminating evidence-based guidelines will lead to different estimates over time and in different fields.

Our challenge is to improve approaches to summarize the evidence, identify strategies to implement programs and practices that will most efficiently improve the health and wellbeing of the population. Its time for greater emphasis in these areas to garner the full return on our past investment in biomedical research across the continuum from prevention to detection, treatment, and community outcomes.

Literature Cited 
  1. Balas, E. A. and S. A. Boren (2000). Managing clincal knowledge for health care improvement. Yearbook of Medical Informaticcs 2000: Patient-centered Systems. J. Bemmel and A. McCray. Stuttgart, Germany, Schattauer.
  2. Bickell, L. (1996). Howard Florey: The Man Who Made Penicillin (Australian Lives series.
  3. Bowen, D. J., G. Sorensen, et al. (2009). "Dissemination research in cancer control: where are we and where should we go?" Cancer Causes Control 20(4): 473-485.
  4. Brownson, R. C. and F. S. Bright (2004). "Chronic disease control in public health practice: looking back and moving forward." Public Health Rep 119(3): 230-238.
  5. Cochran, W. (1937). "Problems arising in the analysis of a series of similar experiments." J R Stat Soc Suppl 4: 102-118.
  6. Crandall, D. (1989). "Implementation Aspects of Dissemination." Science Communication 11(1): 79-106.
  7. Farquhar, J. W. (1996). "The case for dissemination research in health promotion and disease prevention." Can J Public Health 87 Suppl 2: S44-49.
  8. Green, L. W., J. M. Ottoson, et al. (2009). "Diffusion theory and knowledge dissemination, utilization, and integration in public health." Annu Rev Public Health 30: 151-174.
  9. Harlan, W. R. (1998). "Prevention research at the National Institutes of Health." Am J Prev Med 14(4): 302-307.
  10. Huberman AM, Levinson NS, et al. (1981). "Interorganizational Arrangements. An approach to education practice improvement." Knowledge: Creation, Diffusion, Utilization 3(1): 5-22.
  11. Huberman M (1991). "Research utilization: The state of the art." Knowledge, Technology & Policy 7(4): 13-33.
  12. Institute of Medicine (1997). Linking Research to public health practice. A review of the CDC's program of Centers for Research and Demonstration of Health Promotion and Disease Prevention. Washington, DC, National Academy Press.
  13. OECD (2010). OECD Health Data 2010: Statistics and Indicators.
  14. Office of Management and Budget (2010.). Budget: Department of Health and Human Services. . Washington, DC, The Executive Office of the President.
  15. Rogers, E. (1993). Diffusion of innovations. London, The Free Press.
  16. Woolf, S. H. (2008). "The meaning of translational research and why it matters." JAMA 299(2): 211-213.



Study of 1.4 Million Shows Early Deaths Linked to Overweight & Obesity - What Now?

In what in many ways is a definitive study on the topic, a very large analysis of 1.46 million adults further confirms that overweight and obesity significantly increase the risk of mortality (study). The analysis by Berrington de Gonzalez and colleagues, which appears in the New England Journal of Medicine today, pooled together data from 19 prospective studies that followed participants over time - noting participant's body mass index (BMI) and keeping track of participant deaths.

Because health status and smoking status can have an impact both on weight and mortality - sick people often lose weight, and smokers are often lean and prone to dying earlier than non smokers - researchers focused their analyses on participants who were both non-smokers and healthy at the study's start. The goal was to get a truer reflection of the impact that weight could have on health.

What they found was that as BMI increased above the normal range (BMI = 18.5 - 24.9), the risk of premature death went up. Those in the overweight category (BMI = 25 - 29.9) had a 13 percent higher risk compared to those with a BMI of 22.5 - 24.9. Those in the obese category (BMI = 30 - 34.9) had a 44 percent higher risk. While those in the super obese categories with a BMI between 35 - 39.9 and 40 - 49.9 had an 88 percent increase and more than double the risk, respectively. (BMI Calculator).

As found in some other studies, there was also some increase in risk for those who fell in the underweight category (BMI = 15 - 18.4) and in the lower end of the normal range (BMI = 18.5 - 19.9). The data suggest though, that these numbers may be capturing some residual health issues, possibly undiagnosed illness which causes some of this increase in risk among the very lean. Those participants in the underweight category who were regularly active - a marker for good health - had less of an increase in risk than those who weren't active. That the risk linked to underweight largely went away after 15 years of follow-up is another indicator that pre-existing illness may be at work in the group.

Perhaps the most notable finding from the paper is a clear and sustained increase in mortality seen in folks who fall in the overweight category (BMI = 25 - 29.9). Some previous results from some big studies, such as Flegal et al, 2007, found no increase in mortality in this category, most likely because they did not exclude smokers and those with illness as the current paper did.

What this new analysis clearly shows is that maintaining a healthy weight has real health benefits. While there will always be news stories and select journal articles calling into question the true benefits of a healthy weight, this paper shows that in the face of our growing obesity epidemic, where 66 percent of the US population is overweight or obese and therefore at increase risk of pre-mature death, we need to put to rest the question of whether overweight impacts health and start to answer in ernest the question: what are we going to do about it?

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Weight
Diet
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Related Web Resources
Obesity: Economic Burdens and Costs (Graham A. Colditz, MD, DrPH)
Harvard's Nutrition Source