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.
• 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:

1. 1. 1. BRCA 1 or 2 mutation,
      2. A 1^st degree relative with a BRCA mutation who has not been tested for BRCA herself
      3. Radiation to chest between age 10 and 30 years
      4. Lifetime breast cancer risk ≥ 20%.
      5. Li-Fraumeni, Cowden and/or Bannayan-Riley-Ruvalcaba syndromes

• 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:

1. The radiologist saw something that was not completely normal and wants to take a closer look with additional imaging.
2. Most of the time, these abnormalities turn out not to be cancer, but:
3. It is very important that she get the follow-up test(s) to make sure that it is not cancer.
4. Make sure she knows how to follow up (phone number to schedule / have staff assist her).
5. Ask her if she has any questions and uses the teach-back technique to make sure she understands.
6. 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.

https://www.acog.org/About-ACOG/News-Room/News-Releases/2017/ACOG-Revises-Breast-Cancer-Screening-Guidance--ObGyns-Promote-Shared-Decision-Making