|December 2009 · Vol. 21, No. 12
EXAMINING THE EVIDENCE
Does the clinical breast exam boost the sensitivity of mammography?Yes But adding clinical breast examination (CBE) to mammography also increases the rate of false-positive findings, according to a cohort study of 290,230 women in Canada. When CBE was added to mammography for screening, the sensitivity of screening for detecting malignancy increased to 94.9%, compared with 88.6% in centers that did not include CBE. At the same time, the false-positive rate was 12.5% when CBE was included in screening, versus 7.4% when it wasn’t.EXPERT COMMENTARY
Adding a clinical breast examination to mammography increased the sensitivity of screening but also raised the false-positive rate
Fellow in Breast Diseases and Management, Department of Obstetrics and Gynecology, University of Michigan Health System, Ann Arbor, MichMark Pearlman, MD
S. Jan Behrman Professor of Reproductive Medicine; Vice Chair and Service Chief, Obstetrics and Gynecology; and Director, Breast Fellowship in Gynecology; University of Michigan Health System, Ann Arbor, Mich.
Optimal screening for breast cancer is a topic of debate and interest for physicians in many disciplines who play a role in diagnosis and management of this disease. Through improvements in early detection and treatment, we now see longer survival in women who have breast cancer. The burden of disease remains high, however, with one of every eight women in the United States being given a diagnosis of invasive breast cancer.1
Historically, physicians relied on CBE to identify masses. With the advent of mammography, however, and increasing evidence of its efficacy in detecting malignancy, mammography became the new norm for screening, and remains the gold standard for detection of breast cancer. It is clear that mammography can detect some types of lesions long before they can be palpated on clinical exam.
Mammography isn’t perfect
The sensitivity of mammography to detect breast cancer ranges from 68% to 88%, depending on the patient’s menopausal status, breast density, and other characteristics. Certain types of breast cancer, such as invasive lobular carcinoma, are more difficult to detect with mammography. Many major medical organizations, including ACOG and the American Cancer Society, continue to recommend CBE as a component of the screening process. Most ObGyns value their role in screening women for cancer and generally believe that CBE is an important element of well-woman care. In addition, as Barton and colleagues point out, some women are more accepting of CBE than of mammography.2
CBE took 8 to 10 minutes
The Chiarelli study is a large, well-designed study that included women 50 to 69 years old who participated in breast-screening programs in Ontario. Women were screened by mammography alone or mammography combined with CBE. Examinations were standardized and performed by well-trained and certified nurses, and the CBE took an average of 8 to 10 minutes.
Surveys of American women suggest that most of them would accept the possibility of undergoing biopsy for a negative finding for the sake of improving detection of breast cancer. The study by Chiarelli and colleagues supports the current practice of ObGyns and other primary care providers who perform CBE as a component of screening, and is congruent with our patients’ wish to optimize the sensitivity of screening.
To be effective, however, the quality of our exams must be consistent with those described in the study. In a published review, CBE in the community setting did not yield the same sensitivity reported in randomized trials.3 We must remain cognizant of the goals of CBE and educate our patients about the benefits, limitations, and risks of screening.
WHAT THIS EVIDENCE MEANS FOR PRACTICE
After counseling the patient about the possibility of false-positive findings, perform clinical breast examination as part of breast cancer screening (i.e., including mammography). Barton and colleagues suggest that CBE include at least 3 minutes of palpation per breast using specific techniques, including the following:
Begin palpation in the axilla and continue in a straight line down the midaxillary line to the bra line. Move the fingers medially and continue palpation up the chest in a straight line to the clavicle. Move the fingers medially again and palpate back down to the bra line, continuing in this fashion until the entire breast has been covered, with overlapping rows.
Hold the middle three fingers together and slightly flex the metacarpal-phalangeal joint. Use the pads—not the fingertips—to examine the surface of the breast, and palpate each area by moving the fingers in a small circle, as though tracing the outline of a dime. Make three circles at each spot using light, medium, and then deep pressure to ensure that all levels of tissue are palpated.
Palpate the supraclavicular and axillary regions as well as the breast to detect any adenopathy.
Palpate the nipple in the same manner as the rest of the breast.2
—JENNIFER GRIFFIN, MD, MARK PEARLMAN, MD
1. American Cancer Society. Breast Cancer Facts & Figures 2009–2010. Atlanta: ACS; 2009.
2. Barton MB, Harris R, Fletcher SW. The rational clinical examination. Does this patient have breast cancer? The screening clinical breast examination: should it be done? How? JAMA. 1999;282:1270–1280.
3. Elmore JG, Armstrong K, Lehman CD, Fletcher SW. Screening for breast cancer. JAMA. 2005;293:1245–1256.
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