Instructions: Listen to the podcast episode available below, and then submit your answers to the multiple choice questions. You will review the answers and the material covered during your next Continuity Clinic Session.
Breast Imaging and Density
1. A 62 yo G4P4 calls the office after receiving her mammography results in the mail. The report states that she was classified as Category 2 using the Breast Imaging Reporting and Data System (BI-RADS) and that she has extremely dense breasts. The report recommended that she discuss her results with her physician. Menarche was at age 12, and her first child was born at age 25. She had a biopsy 8 years ago for fibrocystic breast disease. Her maternal grandmother had breast cancer in her 60s. In addition to clinical breast exams, what would you recommend for this patients?
Lifetime risk of breast cancer is approximately 12%
Risk factors include early menarche, low parity, family history, delayed childbirth and some genetic factors
Screening mammography should begin at age 40
Symptomatic patients should have a diagnostic procedure that includes mammography and may involve ultrasonography or breast biopsy
Mammography results are reported using the BI-RADS system with risk of underlying malignancy ranging from 0-6.
BI-RADS 1 and 2 have a 0% likelihood of malignancy
Patients with BI-RADS 2 have normal breast tissue but with the presence of other benign structures
Many times breast tissue becomes less dense with age, but up to 50% of women can still have dense breasts later in life Those with extremely dense breasts are at an increased risk of breast cancer compared to those with average breast density, and the detection by mammography is diminished
MRI is cost effective screening for those with >20% risk of cancer (usually based on BRCA, a strong family history or history of chest wall radiation)
Breast ultrasound can have a high false positive rate
Breast xerography enhances fine details like microcalcifications, but images are not superior to current techniques; exposes women to higher radiation levels
Because of limitations in mammography for women with dense breasts, many states have enacted patient notification laws related to breast density but there is no evidence for meaningful benefits with other types of screening (ultrasound, MRI, thermography, xerography, etc).
2. A 25 yo woman presents to your office. Her mother was diagnosed with breast cancer at age 48 and carries the BRCA1 mutation. Your patient recently had genetic counseling and tested positive for the same mutation. What is the most appropriate breast cancer surveillance for this patient?
Cumulative risk of breast cancer by age 70 is 55% for BRCA1 and 47% for BRCA2
Onset of breast cancer in this population is at an earlier age than the general population so screening needs to start earlier
Breast imaging should begin at age 25. Because of the density of breast tissue at this age, MRI is preferred.
Mammography should start at age 30
Many centers use imaging approaches that incorporate imaging every 6 months, alternating between mammography and MRI
Ultrasound is helpful as an adjust in imaging after suspicious mammography or MRI
Risk-reducing mastectomy can reduce the risk of breast cancer in BRCA carriers by 95%
3. A 55 yo G2P2 asks about her risk of developing breast cancer. She has no significant medical history. With the use of the Gail Model Breast Cancer Risk Assessment Tool, you determine her 5-year risk of breast cancer is 3.1% and lifetime risk is 20.1%. To reduce her risk of breast cancer, what is the best medical therapy?
Gail Model is one of a number of risk assessment tools for breast cancer
Only takes into consideration patient age, some reproductive factors, history of breast biopsies and contribution of family history (first-degree female relative)
Elevated risk is considered >= 1.67% over 5 years or lifetime risk >=20%.
At a minimum, these women should be offered enhanced screening: clinical breast exam every 6-12 months, annual mammography and instruction on breast self-awareness
Claus Model helpful in women with at least one female first-degree or second-degree relative who has been diagnosed with breast cancer because takes into consideration extended family history
The Breast Cancer Surveillance Consortium risk calculator includes radiologic breast density
Behavioral modifications have not been shown to decrease breast cancer risk
Tamoxifen was first shown to reduce the risk of breast cancer by 49% in risk-eligible women
Head to head trial of the 2 SERMs (selective estrogen receptor modulators) found that raloxifene is just as effective as tamoxifen at reducing invasive breast cancer but has lower risk of thromboembolic disease, endometrial cancer and need for cataract surgery
Both tamoxifen and raloxifene are approved for breast cancer chemoprevention in post-menopausal women; only tamoxifen is approved for pre-menopausal women
Strongest benefit seen in women with 5-year risk of breast cancer >=3%
Tamoxifen also reduces non-vertebral fractures and raloxifene reduces vertebral fracture risk
Aromatase inhibitors (anastrozole, exemestane) have not been approved for breast cancer chemoprevention and they may accelerate loss of bone mineral density
Leuprolide has no indication for breast cancer prevention and would not have therapeutic benefit in someone who is already post-menopausal. It is used for ovarian suppression in premenopausal women who need to take an aromatase inhibitor as part of adjuvant therapy for breast cancer