HOW TO PREVENT CANCERS

Our letter to the editor (which did not run): 

To the Editor:

Re: Medicine to Deter Some Cancers Not Taken (front page, Nov 13)

It’s well established that healthy lifestyle choices can prevent cancer.  To say otherwise is a great disservice.

A recent report by the American Institute for Cancer Research concluded that maintaining a healthy weight could alone help prevent 100,000 cases of cancer each year in the United States.   Add to this the lower risk associated with physical activity, healthy diet, and not smoking, and the numbers become even more impressive. 

Certain high-risk groups could clearly benefit from chemoprevention with drugs like tamoxifen, raloxifene, and aspirin, and physicians should encourage these drugs with their appropriate patients, while being clear about the risks and benefits. 

But to emphasize chemoprevention medications over lifestyle is misdirected.  Guidelines recommend such drugs for only a small percentage of people, whereas lifestyle choices can benefit the entire population, reducing risk not only for cancer but also for heart disease, stroke, diabetes, and osteoporosis.  

Graham A. Colditz, MD, DrPH
Niess-Gain Professor of Surgery, Professor of Medicine, and
Associate Director Prevention and Control, Alvin J. Siteman Cancer Center,
Deputy Director, Institute for Public Health
Washington University School of Medicine
St. Louis, MO

For more, see our Knol on Cancer Prevention.

In the news last month were details of a large Harvard-based randomized clinical trial that will be testing the potential of vitamin D and fish oil supplements to prevent cancer and heart disease (study site). Called the VITAL study -- from the somewhat forced “VITamin D and OmegA-3 TriaL” – the study plans to recruit 20,000 older men and women beginning January 2010 to be in one of four study groups. One group will take both a vitamin D supplement (2,000 IU) and an omega-3 supplement (1g) each day. One group will take placebos of both each day. And the other two groups will take a combination of supplements and placebos.

Vitamin D has certainly been in the news a great deal over the last couple of years for its possible disease prevention qualities. And while the evidence for benefit has been compelling, most of it has come from observational studies. The VITAL study, and other similar planned trials, should help offer some more definitive information about vitamin D’s benefits, and any risks.

Vitamin D article by the prevention team in Woman & Cancer Magazine: Shedding Light on Vitamin D and Cancer by Graham Colditz, MD, DrPH and Hank Dart, SM

Video featuring Graham Colditz, MD, DrPH on the keys to cancer prevention.


Related web resources:
Your Disease Risk
Cancer Prevention -- Google Knol

A new study this week out of Stanford University found that the more acculturated Asian Americans are, the more likely they are to practice unhealthy patterns of sun exposure (study).

Surveying close to 550 individuals of Asian decent living in northern California, the researchers found that those from families who have been in the US longer, or have lived half or more of their lives in the United States, were much more likely to sunbathe and to prize darker skin than those who lived less time in the US or spent most of their lives in Asia. Strikingly, nearly 60 percent of those raised at least half of their lives in the United States reported that they had practiced sunbathing, whereas only 34 percent of those raised largely in Asia said they did so. Attitudes about safe-sun practices (like using sunscreen) tracked very similarly with levels of acculturation.

With sun exposure the major cause of skin cancer, including deadly melanoma, these results could have obvious health implications for the growing Asian American population in the US, especially since skin cancer diagnoses are often delayed, with more serious results, in Asian groups compared to Caucasians. Clearly, better education of individuals and doctors would be a good first step in addressing this issue.

Beyond this, though, this paper further reinforces what we’ve known in public health for years now: that culture can have a large influence on health behaviors and rates of chronic diseases. Previous studies in Asian populations have found that as immigrants to the US adopt its Western culture, their rates of diseases like heart disease and colon cancer rise to match, or even exceed, those of the US average (figure).

While such findings can certainly be viewed through a gloomy lens, they have a positive side as well: they show the potential power of prevention. If population changes in lifestyle that raise the risk of disease can change so quickly, they also have the potential to move in healthful directions as well.

Of course, it takes a concerted effort from government, communities, and individuals alike to effect such changes, even small ones, populations wide. But it can happen with a combination of large and small steps. So, as you put on your sunscreen, buy your fruits and vegetables, and get outside for a walk, remember you’re not only helping yourself but also helping create a culture of healthfulness that will benefit those around you as well.


Articles referenced:
Gorell E, et al. Adoption of western cultures by Californian Asian Americans: Attitudes and practices promoting sun exposure. Arch Dermatol. 145(5):552-556, 2009.

Flood DM, et al. Colorectal cancer incidence in Asian migrants to the United States and their descendants. Cancer Causes and Control. 11: 403±411, 2000.

Related web resources:
Your Disease Risk -- Melanoma

Cancer Prevention -- Google Knol