Understanding a BI-RADS 3 Imaging Assessment
Imaging Findings: BI-RADS Assessments
Mammogram results are classified using the American College of Radiology's (ACR) Breast Imaging-Reporting and Data System (BI-RADS®) scale. Results range from zero to six, with zero being an inconclusive result and six being a known biopsy-proven malignancy (see figure below). Each score is associated with a range or percentage risk of malignancy. The ACR also categorizes breast density using a BI-RADS assessment of A through D.
BI-RADS Assessment and Management Recommendations
|Assessment||Management Recommendation||Likelihood of Cancer|
|Category 0: Incomplete – Need additional imaging evaluation and/or prior mammograms for comparison||Recall for additional imaging and/or comparison with prior examination(s)||N/A|
|Category 1: Negative||Routine mammography screening||Essentially 0% likelihood of malignancy|
|Category 2: Benign||Routine mammography screening||Essentially 0% likelihood of malignancy|
|Category 3: Probably Benign||Short-interval (6-month) follow-up or continued surveillance mammography||>0% but ≤ 2% likelihood of malignancy|
|Category 4a: Suspicious (low suspicion of malignancy)||Tissue diagnosis||>2% but ≤ 10% likelihood of malignancy|
|Category 4b: Suspicious (moderate suspicion of malignancy)||Tissue diagnosis||>10% but ≤ 50% likelihood of malignancy|
|Category 4c: Suspicious (high suspicion of malignancy)||Tissue diagnosis||>50% but ≤ 95% likelihood of malignancy|
|Category 5: Highly Suggestive of Malignancy||Tissue diagnosis||≥ 95% likelihood of malignancy|
|Category 6: Known Biopsy-Proven Malignancy||Surgical excision when clinically appropriate||N/A|
Of particular concern are women with abnormal or unclear imaging findings, such as a BI-RADS 3 patient. Patients who receive a BI-RADS 3 assessment are informed their imaging result is "probably benign." These women are typically reassessed with six-month follow-up imaging for two years using a "wait and see" approach to confirm that the abnormality is benign. During this time frame, a biopsy is typically not recommended for the patient based on clinical guidelines. This period of watchful waiting causes two years of anxious follow-ups filled with uncertainty for women and ultimately a 98 percent chance that their finding is benign. However, for the other two percent of women, their diagnosis may be delayed.
Current Methods of Detection Rely on Abnormal Anatomical Features
As mentioned in the previous paragraph, a biopsy is not typically recommended for BI-RADS 3 patients. However, some patient may still insist on a biopsy. For instance, in the ACRIN 6666 trial, 124 women with a BI-RADS 3 assessment were biopsied, of which five cancers were identified. This poses questions about whether patients would prefer to have a definitive diagnosis from a biopsy today versus following the "watch and wait" approach recommended by guidelines.
For these women with a BI-RADS 3 score, an additional diagnostic tool that could provide accurate information on their breast abnormalities based on biochemical changes versus anatomical features alone could provide peace of mind and forgo a potentially avoidable biopsy.
Current methods of breast cancer detection do not provide sufficient information, making a healthcare provider's clinical decisions more challenging.
For women with abnormal or unclear imaging findings, healthcare providers are often left to determine whether a biopsy or additional imaging is necessary. While a combination of modalities may increase the sensitivity and detect more cancers, this can also decrease the specificity leading to a cascade of further diagnostic procedures and heightened anxiety for patients without breast cancer.
A Complementary Method of Detection is Needed to Aid Imaging
This proves there is a strong need for a diagnostic complement to imaging in the form of a blood test. When a result comes back unclear from imaging, the blood test could be administered, providing real time detection of breast cancer. This would allow for BI-RADS 3 patients to gain a definitive response when imaging comes back unclear, saving them from two years of restless follow ups as well as reducing the chance of a delayed diagnosis.