654 Obstetrics and Gynecology Board Review •••
❍ How large does a breast mass generally have to be before it is palpable?
Approximately 2 cm.
❍ What size tumor can mammography detect?
1 mm.
❍ What is the description of the time a mass is detected by screening to the time it is palpable?
Sojourn time.
❍ What factors decrease the sojourn time?
Patient’s advanced age and the aggressiveness of the cancer.
❍ When does ACOG recommend beginning screening?
Clinical breast examination should start at the age of 20 and breast imaging should start at the age of 40.
❍ How many women aged 39 to 49 must be screened to prevent one cancer death?
1 in 1904 women.
❍ How many women aged 50 to 59 must be screened to prevent one cancer death?
1 in 1339 women.
❍ What are the imaging modalities available for screening?
Mammography, ultrasound, and MRI.
❍ Why is mammography the preferred method of screening?
Mammography has a high sensitivity 79% and specificity 90% for detecting breast lesions (National
Cancer Institute. “Breast Cancer Screening Modalities” http://www.cancer.gov/cancertopics/pdq/screening/breast/
healthprofessional/page4).
❍ What are the potential adverse consequences of mammographic screening?
False negative mammograms, false positive mammograms, and radiation exposure.
❍ What are the consequences of a false-positive test?
20% to 30% of patients will have an unnecessary biopsy and undue stress.
❍ When should mammography stop?
Women aged 75 and older should consult with their physician on an appropriate time to stop screening.
❍ What role does ultrasound play in screening for breast cancer?
It allows for evaluation of inconclusive mammographic results by identifying cystic versus solid masses, by
evaluating dense breast tissue, and by guidance in core-needle biopsy.