Winter 2008

NEW RESEARCH YOU CAN USE TODAY
The topics below highlight three research studies from the past six months that have relevance in our day-to-day lives and look at the relationship between:

In this newsletter you will also find:

For a printable PDF of this newsletter, click here.

Does folic acid prevent colorectal adenomas?

The Journal of the American Medical Association. 2007 Jun 6;297(21):2408-9.
JAMA. 2007 Sep 26;298(12):1397; author reply 1397.

Between July, 1994 and October 2004, a randomized clinical research study was conducted to look at folic acid and its effect in the large intestine in regard to colorectal cancer. The study included 1,021 men and women with a recent history of colorectal adenomas (a precursor to colorectal cancer) and no previous invasive large intestine cancer.

This double-blind, placebo-controlled, 2-factor, phase 3, randomized clinical trial was conducted at nine clinical centers and assessed the safety and efficacy of folic acid supplementation for preventing colorectal adenomas. Participants were randomly assigned to receive one milligram per day of folic acid or placebo, and were separately randomized to receive aspirin (81 or 325 mg per day), or placebo. Each person received two colonoscopy follow-ups: one at three years and another three or five years later. The primary outcome looked for the occurrence of at least one colorectal adenoma. Secondary outcomes were the occurrence of advanced lesions (cancer) and multiple adenomas.

During the first three years, almost 97 percent of the participants had a colonoscopy follow-up. At least one colorectal adenoma was found in 44 percent of the people who took for folic acid supplements and 42 percent for placebo. At least once advanced lesion (cancer) was found in 11 percent of the people who took folic acid and nearly 9 percent for placebo. Over half of the participants, (59.5 percent) had a second colonoscopy and at least one colorectal adenoma was found again in nearly 42 percent of the people who took folic acid and 37 percent for placebo. And, at least one advanced cancer lesion was found in almost 12 percent of the folks who took folic acid and 7 percent for placebo.

This study concluded that taking folic acid supplements at one milligram per day is actually associated with higher risks of having adenomas and of non-colorectal cancers and does not reduce colorectal adenoma risk. Researchers concluded that further research is needed to investigate the possibility that folic acid supplementation might increase the risk of colorectal neoplasia (abnormal cell growth).

CPC Commentary:
Folic acid now joins a long list of vitamin supplements that do not reduce cancer risk, and may increase risk. This study suggests that folic acid is at best unhelpful and at worst raises the risk of colon cancer. Except for pregnant women, there is no reason to take folic acid supplements.

Coffee consumption and risk of liver cancer: a meta-analysis. Gastroenterology, Volume 132, Issue 5, Pages 1740-1745 S.

Coffee drinkers frequently receive mixed messages about the health effects of their habit, but researchers for this study decided to review the mounting evidence that coffee drinking may really be protective against liver injury and lower the risk of liver cancer.

A meta-analysis was done, looking at other studies from 1966 to February 2007 and included cohort and case-control studies that reported relative risk estimates of primary liver cancer, or hepatocellular carcinoma, related to quantitative categories of coffee drinking.

In nine studies total that involved 2,260 cases and 239,146 non-cases, all observed an inverse relation between coffee consumption and risk of liver cancer. In six studies the association was statistically significant.
Overall, an increase in consumption of two cups of coffee per day was associated with a 43 percent reduced risk of liver cancer. Therefore the researchers concluded that an increased consumption of coffee may indeed reduce the risk of liver cancer.

CPC Commentary
Coffee has been linked to increased and decreased risk for many medical conditions, none conclusively. This meta-analysis suggests coffee may reduce one’s risk for liver cancer. The authors note that coffee contains large amounts of antioxidants, suggesting a reason for the protective effect. Similar conclusions were reached in a different meta-analysis. It is important to keep in mind that the risk of liver cancer is very low in persons who are otherwise in good health. We would not recommend starting coffee drinking to reduce the risk of liver cancer, but for those of us who are coffee drinkers, it’s nice to know that it might be helpful in preventing this disease.

Statins reduce the risk of lung cancer in humans: a large case-control study of American veterans.

Chest. 2007 May;131(5):1282-8.

Commonly used cholesterol-lowering statins have been noted to suppress tumor cell growth. In this study, researchers examined the association of lung cancer and the use of statins in patients enrolled in the Veterans Affairs (VA) Health Care System. Data from the Veterans Integrated Service Networks 16 VA database between 1998 and 2004 was analyzed and included 483,733 patients from eight states in the south central United States.

Researchers first looked at lung cancer cases and the use of statins prior to the diagnosis (with adjustments for age, sex, body mass index, smoking, diabetes, and race). Statistical software was used for statistical computing of the 483,733 patients in the study. Just over one-third of participants were receiving statins and 1.5 percent had a primary diagnosis of lung cancer. Statin use greater than 6 months was associated with a risk reduction of lung cancer of 55 percent. The protective effect of statins was identified across different age and racial groups and was irrespective of having diabetes, smoking, or alcohol use. It was concluded that statins appear to be protective against the development of lung cancer, and further studies need to be done to define the clinical utility of statins as chemo-protective agents.

CPC Commentary

Several observational studies have suggested that people who take statins may have reduced risk for several cancers. In contrast, secondary evaluations of prospective randomized studies of statins (the highest quality type of studies to prove cause and effect) have not shown that statins decrease or increase one’s risk for cancer. There has never been a prospective randomized study designed to test the impact of statins on cancer risk. Such a study would require a very large number of patients and take many years to complete. For now, we do not recommend statins for cancer protection.

MEET OUR STAFF
Matthew F. Hollon

“Good health is so important to the quality of a person's life,” says Dr. Matthew Hollon, internal medicine physician at the Cancer Prevention Clinic and General Internal Medicine Center at UW Medical Center. “As a physician, my responsibility is to understand what health means to each patient to ensure that they have and maintain the best health possible.”

Growing up in eastern Washington State, Dr. Hollon was always interested in science and people – “a standard ingredient for most doctors,” he says. “I had an innate interest to help people.”

Hollon went to University of Washington for his undergraduate studies and stayed on for medical school. He also received fellowship training at UW and earned a Masters of Public Health degree, eventually joining the faculty as an assistant professor of Medicine in the Division of General Internal Medicine.

“I am a generalist,” he says. “Some like to focus on one thing, but that’s not appealing to me. I’m a big-picture person. I truly fundamentally believe that good health is in prevention.”

The attraction to the Cancer Prevention Clinic was a natural for Dr. Hollon. “There are cancers that are preventable,” he says, “as well one can prevent cardiovascular disease and diabetes. The Cancer Prevention Clinic dovetails nicely with general health promotion.”

Part of the even tackling the financial health-care crisis in the United States can be addressed by teaching people how to eat healthfully and get physical activity into their lives, according to Hollon.

“That’s the beauty of bicycle commuting,” he says, referring to his preferred mode of transportation. Hollon exercises every day of the week.

“Look at all the cancers,” he says. “Colon cancer is a disease of western industrialized countries. People will be surprised how good they’ll feel, [once they take on more healthy habits].”

The Cancer Prevention Clinic is a breath of fresh air for a general medicine practitioner like Hollon. “There is time to talk to people, [much more so than in a typical annual visit setting.] We provide intensive advice about making life changes, and you need time to do that. The clinic is great because as a doctor, I don’t feel rushed. Discussions around screenings and shared decision making are fairly complex. It’s nice to have the time to go through it and describe the magnitude, benefits, and risks.”

Hollon’s personal interests include outdoor activities like skiing, hiking, and climbing. He also enjoys reading fiction and non-fiction books.

His clinical interests include how primary care medicine is practiced including screening for disease. “I am also interested in the things that can potentially affect this practice including but not limited to mass media.”

More information about Dr. Hollon is available on the UW Medicine site. Click here to read his biography: http://medical.washington.edu/bios/view.aspx?CentralId=12529

CANCER PREVENTION TIP

Learn your family's history of cancer and disease. Some types of cancer tend to run in families, such as breast, colorectal, ovarian, and prostate cancers. Talk with your doctor about your family history of cancer and other diseases. Learn more about what types of cancer your child may be at risk for and if there are proven prevention steps to minimize risk, include following some of the steps included on this site, and participate in recommended screenings.

To read more about the choices you can make to help prevent cancer, go to http://www.seattlecca.org/patientsandfamilies/CPC/Choices.htm

IS THAT SO?

Cell phones and cancer
It is a popular worry among parents and others that too much cell phone will cause cancer Ionizing radiation such as gamma rays and X-rays can increase cancer risk by causing changes to DNA in cells of the body. Cell phones, microwave ovens and related appliances emit low-frequency radiation — the part of the electromagnetic spectrum that includes radio waves and radar. Low frequency, non-ionizing radiation does not cause these DNA changes. Considerable research has found no clear evidence to support the notion that cell phones cause cancer, or any other electronic consumer products for that matter.

The ACS book Cancer: What Causes It, What Doesn't provides a look at what cancer health hazards people may face in everyday life, and what's not worth worrying about.

December 2007


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