Medical Edge Newspaper Column

Mammography Still Crucial In Breast Cancer Detection

Jan. 23, 2006
DEAR MAYO CLINIC:
I'm 50 years old and confused about the usefulness of mammography. Is it worth the trouble to get one? -- Green Bay, Wis.

ANSWER:
Yes, most definitely! And here's why:

Breast cancer is the most common cancer in women in the United States -- with an estimated 216,000 new cases of Stage I-IV (invasiveness) diagnosed in 2004. Of these cases, about 40,100 women will die from the disease. Breast cancer is the second leading cause of cancer death in women, just after lung cancer.

Although the role of mammography has been questioned in recent years, deeper analyses and survival trends reveal that mammography is a valuable early detection tool that can reduce mortality from breast cancer. As a result, mammography remains the cornerstone of breast cancer detection.

Women need to take all steps to detect breast cancer early, when it's most curable. General recommendations include:

• Clinical breast exams done by an experienced physician every one to three years, depending upon age. Up to 10 percent of breast cancers can be detected manually -- yet not show up on the mammogram.

• Monthly self-exams.

• Screening mammograms.

Experts, however, don't agree on the exact frequency with which women should get mammograms. The American Cancer Society recommends a yearly mammogram beginning at age 40, while the National Cancer Institute recommends that women 40 and older have a mammogram every one to two years. Conflicting recommendations can confuse patients. Turn to your doctor for guidance.

Your doctor will advise you about how often to get screening mammograms based on your age and family history. For example, women whose mothers, sisters, aunts or grandmothers have had breast cancer are at an increased risk for inheriting mutated (changed) genes linked to the hereditary form of the disease. If genetic tests reveal mutations, a woman should begin getting screening mammograms at age 25, or 10 years earlier than the age at which the youngest member of the family developed breast cancer.

In general, doctors recommend that women at increased risk of breast cancer due to mutated genes get a mammogram each year. Unfortunately, studies show that screening mammograms in this at-risk population detect early signs of abnormal breast tissue in only 33 percent of cases. Because of this, doctors sometimes advise patients to have a breast magnetic resonance imaging (MRI) study. While breast MRI detects 90 percent to 100 percent of cancers, it's expensive and has not been endorsed as a routine screening tool.

As you can see, studies are needed to clarify the optimal role that each technology can play. A positive fact is that indeed new technologies are under development. And even though mammogram screening has some weaknesses, there are many more strengths including early detection and helping to improve survival due to breast cancer. I encourage you to take advantage of this widely available tool.

-- Edith Perez, M.D., Hematology/Oncology, Mayo Clinic, Jacksonville, Fla.