Winter 2007

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 right now:

Also in this issue:

For a printable PDF of this newsletter, click here.

Fish consumption and breast cancer risk. The European Prospective Investigation into Cancer and Nutrition (EPIC).

In the July 1, 2006 issue of “International Journal of Cancer,” researchers from the Institute of Community Medicine, University of Tromso in Tromso, Norway reported on their study investigating the relationship between eating fish and breast cancer risk.

Omega-3 fatty acids have been touted in the press for many years as a healthful choice, especially for women, seeking to prevent breast cancer. While some studies involving animals have suggested that Omega-3 fatty acids may prevent growth of breast cancer cells, results of studies in humans have been inconsistent.

In the University of Tromso study, 310,671 women between the ages of 25 and 70 years completed a dietary questionnaire for six years, from 1992-98, and were then followed for a median of 6.4 years. During follow-up, 4,776 invasive breast cancer cases were reported, indicating to researchers that no significant association exists between the intake of total fish and breast cancer risk. When examining lean and fatty fish separately, they found a significant positive association, but only in those who consumed the highest amounts of fatty fish. There was no significant trend and no associations with breast cancer risk observed when study participants were subdivided by menopausal status. Although the period of follow-up is relatively short, the results provide no evidence for an association between fish intake and breast cancer risk.

CPC COMMENTARY: This study—the largest to date looking at fish consumption and breast cancer risk—finds that eating fish does not protect against breast cancer

The following is a summary from the International Journal of Cancer. 2006 Jul 1;119(1):175-82

The metabolic syndrome and risk of incident colorectal cancer

This study’s authors from the Division of Epidemiology and Community Health, School of Public Health at the University of Minnesota in Minneapolis, sought to determine if the metabolic syndrome is a risk factor for colorectal cancer. Persons with the metabolic syndrome have three or more of the following: high blood pressure, increased waist size (circumference), high blood triglyceride levels, low levels of high-density lipoprotein (good) cholesterol, diabetes, or elevated fasting blood sugars.

Data from the Atherosclerosis Risk in Communities multi-center study were used as were metabolic syndrome components and other risk factors collected from 14,109 men and women between 1987 to 1989. Following these individuals through the year 2000 there were194 new cases of colorectal cancer. The researchers found that persons with the metabolic syndrome (three or more components vs. zero components) had a higher risk of colorectal cancer compared to those who did not have the syndrome. This association was shown to be stronger in men than in women.

Their conclusion is that in this population, metabolic syndrome was a risk factor for incident colorectal cancer in men but not women. Evidence is growing that the metabolic syndrome influences cancer onset and progression.

CPC COMMENTARY: Persons with the metabolic syndrome appear to have a higher risk for colon and rectal cancer. Such individuals should be especially vigilant about getting recommended colon cancer screening.

The complete study was published in Cancer. 2006 Jul 1;107(1):28-36. Ahmed RL, Schmitz KH, Anderson KE, Rosamond WD, Folsom AR. (Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, Minnesota 55454-1015, USA.)

Statin use and breast cancer: prospective results from the Women's Health Initiative

Despite experimental observations suggesting that statins (drugs prescribed to help lower cholesterol) have anti-tumor properties, clinical studies have reached mixed conclusions about the relationship between statin use and breast cancer risk.

To investigate the associations between potency, duration of use, type of statin used, and the risk of invasive breast cancer, researchers from the Department of Epidemiology at the University of Pittsburgh examined data for 156,351 postmenopausal women who were enrolled in the Women's Health Initiative.

Information was collected on breast cancer risk factors and on their use of statins and other cholesterol-lowering drugs. Over an average follow-up of 6.7 years, 4,383 breast cancers were confirmed by medical record and pathology report review. Statins were used by 11,710 (7.5 percent) of the participants. Hydrophobic statins (i.e., simvastatin, lovastatin, and fluvastatin) were used by 8106 women, and their use was associated with an 18 percent lower breast cancer incidence. Use of other statins (i.e., pravastatin and atorvastatin) or nonstatin cholesterol-lowering agents was not associated with breast cancer incidence.

Study researchers concluded that statin use was not associated with risk of breast cancer. Hydrophobic statins may be associated with lower breast cancer risk, but researchers caution that this finding needs further evaluation from other studies.

CPC COMMENTARY: Statins—drugs commonly prescribed to treat high cholesterol—do not increase women’s risk for breast cancer.

The complete study can be found in the The Journal of the National Cancer Institute. 2006 May 17;98(10):700-7. Cauley JA, McTiernan A, Rodabough RJ, LaCroix A, Bauer DC, Margolis KL, Paskett ED, Vitolins MZ, Furberg CD, Chlebowski RT; Women's Health Initiative Research Group

Is That So?

This section features new cancer research findings and what it actually means in terms of preventing, detecting, and treating cancer. Articles are reproduced in full and are followed by a commentary from a member of the Cancer Prevention Clinic care team.

Symptom Screening May Detect Ovarian Cancer Earlier
Reproduced from “Reuters Health” (NEW YORK DEC 11, 2006)

ISSUE: Ovarian cancer has been called the "silent killer" because women usually don’t develop symptoms until the cancer has reached an advanced stage. Women are sometimes told by their doctors that symptoms such as pelvic pain or bloating are worrisome for ovarian cancer.

INVESTIGATION: A team of U.S. researchers tried to find symptoms that could prove useful in screening women for ovarian cancer. By setting a duration and frequency for the symptoms, the investigators were able to detect ovarian cancer with some accuracy (January 15, 2007 issue of “Cancer”). They found six symptoms that were associated with a risk for ovarian cancer:

pelvic pain
abdominal pain
increased abdominal size
bloating
difficulty eating
feeling full.

The researchers found that the symptoms had to occur at least two times per month and be present longer than one year to be reasonably predictive of ovarian cancer.

Lead author Dr. Barbara A. Goff, a gynecologic oncologist at SCCA , said "We showed that symptoms can still occur even with early-stage disease, which raises the possibility of early detection and treatment."

So should patients and doctors start using these symptoms to find early ovarian cancer?

Although this study might appear promising, using symptoms for ovarian cancer screening has proven very problematic. The problem is that the symptoms used in the screening test also occur in a number of benign diseases. They could even be present in men. Furthermore, the symptoms also didn’t do a good job of finding cancer at an early stage (only slightly better than flipping a coin to decide if one has cancer), although they worked better for the oldest and youngest group of women. Even Dr. Goff said that the symptom index "is not ready for prime time.” The team is calling for future research to help doctors and patients find a better group of symptoms that can be used to find ovarian cancer at an early, curable stage. Cancer Prevention Center physicians agree.

TAKE-HOME POINT: Right now, symptoms are not a reliable way to detect early ovarian cancer.

Reproduced from “Reuters Health” (New York, Dec. 11, 2006)
Symptom Screening May Detect Ovarian Cancer Earlier
Anthony J. Brown, Reuters Health, Dec. 11, 2006

CANCER PREVENTION TIP #1: 5-A-Day Rule, the minimum goal

After reviewing thousands of studies on diet and cancer prevention, in 1997 a panel of experts from the World Cancer Research Fund determined that by eating 15 to 30 ounces of vegetables and fruits a day (that’s five to 10 servings) a person could substantially reduce their risk of getting cancer.

In 2005, USDA Dietary Guidelines recommended an average of nine servings (or about four cups) of fruits and vegetables (two cups each) per day for a 2000-calorie diet (www.mypyramid.gov).

This may sound like a lot, but it’s quite easy to reach that goal. Have a piece of fruit with breakfast. Put some vegetables in your sandwich or add some to your microwaveable lunch. Have another piece of fruit for a snack during the day, and fill your dinner plate with a rainbow of colorful vegetables.

“This will likely provide more than (the minimum) five servings or 2.5 cups of fruits and vegetables per day,” says Sarah Washburn, nutritionist at the Seattle Cancer Care Alliance. “More importantly however may be the benefits of eating different colors of fruits and vegetables.”

For USDA recommendations for actual amounts of dark green, orange, legumes, starchy vegetables, and other vegetables to eat per week, click here. For snack and meal ideas, click here.

January 2007


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