Spring 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:

American Cancer Society Guidelines for Breast Screening with MRI as an Adjunct to Mammography
Breast Cancer Screening for Women in Their 40s: Moving from Controversy about Data to Helping Individual Women
Prolonged effect of calcium supplementation on risk of colorectal adenomas in a randomized trial.

Also in this issue:

For a printable PDF of this newsletter, click here.

American Cancer Society Guidelines for Breast Screening with MRI as an Adjunct to Mammography CA Cancer J Clin 2007; 57:75-89

Mammography is an effective tool in the detection of early breast cancer before symptoms develop. Using low-dose X-ray imaging, mammograms provide radiologists two-dimensional views of the breast tissue—irregularities in this tissue are detected, often before they are possible to feel. When combined with appropriate follow-up testing and treatment, regular mammograms can reduce a woman’s risk for death from breast cancer.

Magnetic resonance imaging (MRI) provides a different type of picture of the breast tissue. Using magnetic fields in specialized scanning machines, MRI provides images that are useful in distinguishing between the soft tissues of the body, including in the breast. These images can be viewed in cross-section, and allow radiologists to look for evidence of breast tumors in a way different from mammograms.

In this article, the American Cancer Society (ACS) has provided recommendations to medical providers on when MRI might be used together with mammograms to screen certain women for breast cancer. These recommendations included input from Drs. Wylie Burke and Constance Lehman from Seattle Cancer Care Alliance and the University of Washington. To make these recommendations, the ACS reviewed the most recent scientific studies on this topic. For certain parts of these recommendations, this group provided their “best guess” based upon their expert opinions.

The group reviewed six major studies that were designed to try to see if adding annual MRI scans to annual mammograms made it more likely to find early breast cancer. These six studies were not for “average” risk women—they were conducted in groups of women at much higher risk for breast cancer than others. Generally, these studies showed that—in these groups of women with very high risk for cancer—the MRI scans were more sensitive at finding tumors compared to mammograms. However, the MRI scans found many tumors that were not cancerous, leading to more additional tests and biopsies than mammograms alone. Although these additional tests and biopsies can usually be done safely, the greater number of “false positive” results from MRI scans can lead to greater worry, anxiety, and costs for many women.

Because mammograms are very effective in screening women for breast cancer, the ACS (and the Cancer Prevention Clinic) recommends regular mammograms to find this disease at an early, treatable stage. The ACS recommends the addition of MRI scans for only those small number of women at very high risk for breast cancer—these include women with certain genetic mutations that can lead to higher risk for cancer (such as BRCA1 or BRCA2 mutations), and a past history of radiation treatment to the chest for Hodgkin’s lymphoma.

At this point, MRI scans are not recommended for women who are not in these groups with very high risk for breast cancer. This guideline suggests adding MRI screening to regular mammograms only if a woman’s lifetime risk for breast cancer is much higher (20-25% lifetime risk) than other women. Many questions remain about whether these tests are helpful for other groups of women and whether they are able to lower the risk of death from breast cancer. Because of these remaining questions, and because MRI scans are more likely to lead to additional biopsies, the ACS (and the Cancer Prevention Clinic) does not recommend this test routinely for most women.

CPC COMMENTARY:
Although routine MRI screening for breast cancer is not recommended for most women, SCCA Cancer Prevention Clinic physicians can help interested women estimate their individual risk for breast cancer. Understanding these individualized risk estimates can be useful for those who wish to discuss whether MRI testing would be useful to add to regular mammograms.

Read the complete article here.

Breast Cancer Screening for Women in Their 40s: Moving from Controversy about Data to Helping Individual Women
Annals of Internal Medicine 2007; 146:529-31

Regular mammography has been an important tool in detecting and finding breast cancer early enough to provide a cure. Most of the scientific evidence that has shown this improvement has been for women older than 50—annual mammograms for women between the ages of 50-74 has been proven to reduce the risk of death from breast cancer. However, there has been controversy about at what age to begin this regular screening, and at what age to stop mammograms. Although several organizations (such as the American Cancer Society) have endorsed mammograms for women in their 40s, this topic has remained controversial because the scientific evidence has not always shown clear benefit in this group.

The American College of Physicians (ACP) is the nation’s largest medical specialty society, consisting of physicians of general internal medicine and related subspecialties. To provide guidance on breast cancer screening for women in their 40s, the ACP produced recommendations after reviewing the enormous amount of research on the benefits and harms of providing mammograms for women in their 40s—over 100 articles on this topic were carefully reviewed. This editorial—co-authored by SCCA’s Dr. John Choe, one of the physicians for the Cancer Prevention Clinic—reviews and provides context for these ACP recommendations.

The ACP recommended that women in their 40s should first discuss with their doctors whether screening for breast cancer with annual mammograms is the right decision for them. To make this decision, these guidelines suggest that doctors provide an individualized assessment of each woman’s risk for developing breast cancer, and that they discuss carefully the benefits and harms from mammograms.

Although many women are aware of the benefits from regular mammograms, fewer have had an opportunity to discuss some of the harms from this screening test that can include worry and anxiety from abnormal mammograms (many of the tumors on these tests are benign, non-cancerous tumors), and additional costs from tests (such as time spent away from work to have additional tests).

In this editorial, Drs. Choe and Elmore discuss how the benefits for regular mammograms are less dramatic for women in their 40s compared to older women. In one example, they explain how if 10,000 40-year-old women get annual mammograms for a decade, around 6 women with breast cancers would be detected early enough to treat—in this group, around half would have a false positive mammogram, and around one in five would undergo a breast biopsy. The authors use this example to illustrate some of the risks—as well as the benefits—for starting mammogram screening for all women at age 40.

CPC Commentary
In avoiding a “one size fits all” recommendation for women, the American College of Physicians has recognized that starting annual screening may not be the right decision for all women in their 40s. Instead, the ACP begins with the importance of an individualized conversation between each woman with their physician, before moving forward with mammograms.

The physicians at the Cancer Prevention Clinic can help provide this individualized assessment for your risk of breast cancer, and can spend the time to discuss the advantages and risks of mammograms. Knowing this information can help you decide whether starting regular mammograms is right for you.

Read the complete editorial here.

Prolonged effect of calcium supplementation on risk of colorectal adenomas
J Natl Cancer Inst. 2007 Jan 17;99(2):129-36. Comment in: J Natl Cancer Inst. 2007 Jan 17;99(2):99-100.

Calcium supplementation has been shown to decrease the risk of recurrence of colorectal adenomas (polyps) in randomized trials. However, the duration of this protective effect after stopping these supplements is not known.

In the Calcium Polyp Prevention Study, people who had previous colorectal adenomas were randomly assigned from 1988 to 1992 to receive a placebo or 1200 mg of calcium supplements every day for 4 years. The researchers then continued to watch these participants for several years after the end of this study, to see how many developed more adenomas. They also checked to see what other medications, vitamins, and supplements were taken by participants in the years following the original study.

More than half of these participants underwent at least one colonoscopy after the end of study treatment. The researchers found that people who had received calcium supplements in the original study had a significantly lower risk for 5 years for any new adenomas compared to those who had received placebo. However, whether participants received calcium or placebo did not make a difference in the risk for polyps during the next 5 years (6-10 years after the original study).

The researchers concluded that the protective effect of calcium supplementation on risk of colorectal adenoma recurrence extends up to 5 years after cessation of active treatment, even after stopping caclium supplementation.

CPC COMMENTARY:
Preventing colon and rectal adenomas is important to reduce the risk of colorectal cancer, since these polyps change over time and can develop into cancerous tumors. Researchers from the Fred Hutchinson Cancer Research Center and the University of Washington are working to develop a better understanding of how vitamins and minerals affect colorectal cancer, since nutrition is thought to be one of several important factors that influence the risk of polyps. In addition to offering screening for colorectal polyps, the physicians and nutritionists of the Cancer Prevention Clinic can help you review the latest information on how calcium and other supplements can affect your risk for cancer.

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.

ISSUE: Can saw palmetto prevent prostate cancer?

INVESTIGATION: Saw palmetto, Serenoa repens, is a berry extract from the palmetto shrub, a low-growing tree found in the West Indies and along the coast of the southeastern United States. Scientific evidence does show that saw palmetto relieves some symptoms of benign prostatic hyperplasia (BPH), such as difficulty with or frequent urination. These improvements were similar to those seen in men who took the prescription drug finasteride (Proscar) for BPH. Saw palmetto caused fewer and milder side effects than finasteride. Long-lasting effects of saw palmetto are unclear. There are, however, no studies showing saw palmetto can prevent or treat prostate cancer.

TAKE-HOME POINT: Saw palmetto may be helpful for some men with symptoms related to benign prostatic hyperplasia, but further research needs to be completed before this can be widely recommended. Although commonly used for prostate symptoms, it is important to remember that saw palmetto does not prevent or treat prostate cancer, which is usually “silent” without symptoms for most men. Saw palmetto does not seem to interfere with the measurement of prostate-specific antigen (PSA, a protein made by prostate cells which is used in testing for prostate cancer), but this has not been studied extensively. Since saw palmetto affects testosterone metabolism, CPC doctors recommend that men have a baseline PSA test and digital rectal exam before starting treatment with saw palmetto. Men should always seek a doctor’s opinion before starting any herbal remedy, like saw palmetto.

Meet the Staff

Dr. John Choe: Being a doctor means being a good teacher

Dr. John Choe completed his undergraduate studies at Brown University in Rhode Island and then spent a year teaching high school before attending the New York University School of Medicine.

“The running theme throughout those years was education,” says Choe. “The best part of what I do is to teach and share information with my patients. When I first became interested in becoming a physician, I learned that the word “doctor” comes from the Latin word for teacher. I’ve really tried to take that to heart.” More >

CANCER PREVENTION TIP #2: Vitamin D from sunshine – in moderation

After living through yet another dripping wet winter in the Pacific Northwest, we’re all ready to dry out and get some sun and maybe even get a little of that “healthy” glow. Sun rays are great for all kinds of things, from growing cancer-preventing fruits and vegetable, to improving one’s mood. An additional benefit is that modest amounts of sun exposure can help the skin to produce Vitamin D. Some recent scientific research suggests that this vitamin—which can be from foods and supplements as well as from the sun—may help provide protection from certain types of cancer, although the benefits and risks of this vitamin are still being studied.

However, this should not be used as a reason to get too much exposure to the sun, since it’s well known that too much radiation from the sun’s ultraviolet (UV) rays can be harmful. According to the U.S. Food & Drug Administration, new research may now make these warnings even more important, since UV radiation can cause malignant melanoma, the most serious type of skin cancer.

Skin cancer cases have been rising due to increasing exposure to UV radiation from the sun, tanning beds, and sun lamps. More than 1 million new skin cancer cases are likely to be diagnosed in the U.S. this year. Do your part to not be one of these million new skin cancer cases: Wear sunscreen with a high SPF number, applied at least 20 minutes before going out in the sun. Be sure to wear protective clothing and wide-brimmed hats whenever you’re outside. To find more ways of protecting yourself and your family from skin cancer, go here.

Cancer Prevention Clinic nutritionists can help you assess your vitamin D needs and identify the best sources. Call (206) 288-7222.

May 2007


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