Resident Editors: Lien B. Le, MD; Anita Hargrave
Faculty Editor: Leah Karliner, MD
BOTTOM LINE ✔ BI-RADS 0 needs immediate follow-up with further diagnostic imaging because imaging is incomplete ✔ BI-RADS 4or 5 needs timely follow-up with biopsy ✔ False positives are common. It is important to communicate clearly with patients about abnormal results and have the patient get the recommended follow-up |
Background:
- Screening recommendations based on the 2016 USPSTF Guidelines:
- Women 50-74 years old: Screening mammogram every 2 years.
- Women 40 – 49 years old: Discuss potential risks and benefits of screening to facilitate patient-centered decision-making. Patients with first-degree relatives with breast cancer are more likely to benefit from screening. If proceeding with screening, biennial screening is recommended by USPSTF.
- Of note, ACOG recommends offering screening mammography at age 40 with testing intervals every 1- 2 years, based on shared decision making.
- Women ages ≥ 75: Per USPSTF, evidence is insufficient to judge the utility of screening.
- ACOG recommends a discussion with the patient, taking into consideration life expectancy, functional status, and goals of care
- All Women: Research on Digital Breast Exam (DBT) as a primary screening method has been insufficient.
- Dense Breast Tissue: Insufficient evidence to recommend additional screening using breast ultrasonography, MRI, DBT after a negative screening mammogram noted dense breast tissue in average-risk individuals.
- Women 50-74 years old: Screening mammogram every 2 years.
- Consider screening with breast MRI in high-risk women
- American Cancer Society and the National Comprehensive Cancer Network recommend annual MRI with mammography for women with one of the following:
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- BRCA 1 or 2 mutation,
- A 1st degree relative with a BRCA mutation who has not been tested for BRCA herself
- Radiation to chest between age 10 and 30 years
- Lifetime breast cancer risk ≥ 20%.
- Li-Fraumeni, Cowden and/or Bannayan-Riley-Ruvalcaba syndromes
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- After a screening mammogram, there are six possible results under the BI-RADS (Breast Imaging Reporting and Data System) classification from the American College of Radiology:
Interpretation of BI-RADS Score:
BI-RADS Result Recommended Follow-up
· 0 Incomplete Immediate follow-up (diagnostic imaging)
· 1 Negative Routine screening follow-up
· 2 Benign finding(s) Routine screening follow-up
· 3 Probably benign Short-interval follow-up (6 months)
· 4 Suspicious abnormality Immediate follow-up (biopsy)
· 5 Highly suggestive of malignancy Immediate follow-up (biopsy)
· 6 Known biopsy-proven malignancy Treatment for breast cancer
Chance of malignancy
- BI-RADS 3: ~2% chance of malignancy
- When repeat mammography is done at 6 months, if there is a progression of the lesion then immediate evaluation is necessary; whereas if the lesion remains stable, the patient can be evaluated at an additional 6-month interval and if still stable, regular screening interval may be resumed.
- BI-RADS 4: 2-95% chance of malignancy
- 4A: Low suspicion. Chance of malignancy 2-9%
- 4B: Moderate suspicion. Chance of malignancy 10-49%
- 4C: High suspicion. Chance of malignancy 50-94%
- BI-RADS 5: 95-100% chance of malignancy
BI-RADS 0 (Incomplete) result
- 0 (Incomplete) is the most common abnormality reported on a screening examination.
- Order a follow-up diagnostic mammogram with spot compression views and diagnostic ultrasound to follow the mammogram if it is unrevealing.
- The result will then be resolved as either a BI-RADS 2 (benign finding) or BI-RADS 4 or 5 needing biopsy (either FNA or core).
Biopsy Options
- For non-palpable lesions detected by a mammogram, a core needle biopsy is preferred over fine-needle aspiration (FNA) biopsy, since more tissue is obtained for histologic diagnosis. Core needle biopsy is more accurate compared with FNA biopsy, which is more operator-dependent. For palpable breast masses, refer to “Approach to Palpable Breast Mass.”
- Image-guided FNA biopsy may be used for sampling very thin breast tissue or lesions close to the chest wall, where core biopsy is not technically feasible.
- However, for small areas of highly suspicious micro-calcifications with no mass, there may be more of a sampling error with core-needle biopsy; referral for location excision can provide definitive treatment.
False positives
False-positive results are common. The overall cumulative risk of a false positive after 10 mammograms is between 21-49%. For women age 40-49, it is up to 56%.
Communication with patients
Good communication about abnormal results is related to appropriate and timely follow-up.
When talking with a woman about her abnormal screening mammogram result, particularly when it is a BI-RADS 0 result, it is important to emphasize the following:
- The radiologist saw something that was not completely normal and wants to take a closer look with additional imaging.
- Most of the time, these abnormalities turn out not to be cancer, but:
- It is very important that she get the follow-up test(s) to make sure that it is not cancer.
- Make sure she knows how to follow up (phone number to schedule / have staff assist her).
- Ask her if she has any questions and uses the teach-back technique to make sure she understands.
- If she is non-English speaking, use a professional interpreter over the phone in a 3-way call to have this conversation.
References:
D’Orsi CJ, Sickles EA, Mendelson EB, Morris EA, et.al. (Eds). The American College of Radiology Breast Imaging Reporting and Data System (BI-RADS). 5th ed. Reston, VA: American College of
Kerlikowske K, Smith-Bindman R, Ljung BM, Grady D. Evaluation of abnormal mammography results and palpable breast abnormalities. Ann Intern Med. 2003 Aug 19; 139(4):274-84.
Mettler FA, Upton AC, Kelsey CA, Ashby RN, Rosenberg RD, Linver MN. Benefits versus risks from mammography: a critical reassessment. Cancer. 1999;77(5):903
Siu AL, Peters JJ, Bibbins-Domingo K, et al. “Final Recommendation Statement.” Breast Cancer: Screening - US Preventive Services Task Force, U.S. Preventive Services Task Force, 12 Jan. 2016, www.uspreventiveservicestaskforce.org/Page/Document/RecommendationStatementFinal/breast-cancer-screening1.
Saslow D, Boetes C, Burke W. et al. American Cancer Society Guidelines for Breast Screening with MRI as an Adjunct to Mammography. CA: A Cancer Journal for Clinicians. 2009 Feb 19. 57(2).
Tirona MR. Breast cancer screening update. Am Fam Physician. 2013 Feb 15; 87(4):274-278.
The American College of Obstetricians and Gynecologists. ACOG Revises Breast Cancer Screening Guidance: Ob-Gyns Promote Shared Decision Making. ACOG. 2017 Jun 22.