Getting a mammogram can be nerve-wracking, especially when the results mention a term like BI-RADS 3. Many women naturally worry that any abnormality means cancer — but that’s not the case. A BI-RADS 3 result actually means “probably benign”, and the chances of it being cancer are very low.
In this article, we’ll break down what BI-RADS 3 means, what percentage turn out to be cancer, why follow-up is needed, and how to manage your concerns while waiting for results.
What Is the BI-RADS System?
The Breast Imaging Reporting and Data System (BI-RADS) is a classification framework developed by the American College of Radiology (ACR). It standardises how radiologists describe mammograms, ultrasounds, and MRIs — making reports clearer for both doctors and patients.
There are seven BI-RADS categories (0–6):
- BI-RADS 0: Incomplete – additional imaging needed
- BI-RADS 1: Negative – normal mammogram
- BI-RADS 2: Benign finding – noncancerous
- BI-RADS 3: Probably benign finding – very low chance of cancer
- BI-RADS 4: Suspicious abnormality – biopsy recommended
- BI-RADS 5: Highly suggestive of malignancy – strong indication of cancer
- BI-RADS 6: Known biopsy-proven cancer
Each step up the scale represents a higher likelihood that a finding could be cancerous. BI-RADS 3 is near the bottom, meaning the finding is overwhelmingly likely not to be cancer.
What Does BI-RADS 3 “Probably Benign” Mean?
A BI-RADS 3 result indicates a finding that has the classic features of a benign (noncancerous) change in the breast. However, because the radiologist wants to be absolutely sure, they will recommend a short-term follow-up instead of an immediate biopsy.
Typical examples of BI-RADS 3 findings include:
- A small, round, or oval mass with smooth edges
- A cluster of tiny calcifications that appear stable
- A focal asymmetry that doesn’t look worrisome but wasn’t seen before
- A simple cyst or fibroadenoma that appears benign
These findings don’t scream “cancer,” but doctors prefer to double-check that they remain stable over time.
What Percentage of BI-RADS 3 Is Cancer?
According to data from the American College of Radiology and multiple large studies, the risk of cancer for a BI-RADS 3 lesion is less than 2%.
That means out of every 100 women who receive a BI-RADS 3 result, 98 to 99 will not have cancer, and only 1 to 2 might.
Here’s what major studies show:
- A 2020 review published in Radiology found the cancer rate for BI-RADS 3 findings was around 1.5%.
- Research in The Breast Journal reported that the majority of BI-RADS 3 findings remained stable after multiple follow-up exams.
- In cases where cancer was found, it was typically at an early stage, thanks to close imaging follow-up.
So, while it’s understandable to feel anxious, the odds are overwhelmingly in your favour.
Why Doctors Recommend Follow-Up Imaging
Even though BI-RADS 3 findings are “probably benign,” radiologists don’t ignore them. Instead, they use a watchful waiting approach.
You’ll typically be asked to have:
- A 6-month follow-up mammogram or ultrasound
- Another at 12 months, and again at 24 months if the finding remains stable
If no changes are seen during that time, the finding is reclassified as BI-RADS 2 (benign), and you return to routine annual screenings.
However, if the finding grows, changes shape, or shows new features, your doctor may recommend a biopsy to rule out malignancy.
Factors That Influence BI-RADS 3 Classification
A BI-RADS 3 result doesn’t mean the same thing for everyone. Radiologists consider a patient’s personal and family history, as well as other medical and hormonal factors, before deciding on the best follow-up plan.
Some factors that may influence interpretation include:
- Age: Younger women often have denser breast tissue, which can make images harder to read.
- Family history: A strong family history of breast cancer may prompt earlier or more frequent follow-ups.
- Hormonal changes: Menstrual cycles, pregnancy, and menopause can all affect how breast tissue looks on imaging.
- Previous imaging: Comparing past mammograms helps determine whether a finding is new or stable.
Your healthcare team will personalise your monitoring schedule based on these details.
What Happens If a BI-RADS 3 Finding Changes?
If your follow-up imaging shows that the finding has changed — for example, it’s grown larger, changed shape, or developed irregular edges — your doctor may recommend a core needle biopsy to collect a tissue sample.
A biopsy is the only way to confirm whether a finding is cancerous. Even then, most BI-RADS 3 changes turn out to be benign cysts, fibroadenomas, or tissue changes rather than cancer.
Emotional Impact: Dealing With BI-RADS 3 Anxiety
Even knowing the risk is low, waiting for follow-up imaging can be stressful. Here are some ways to manage that anxiety:
- Ask questions: Your radiologist can explain exactly what they saw and why it’s considered low-risk.
- Stick to your follow-up schedule: Keeping your appointments ensures that any potential changes are caught early.
- Stay informed: Understanding what BI-RADS 3 means can reduce uncertainty and help you feel in control.
- Practice self-care: Managing stress through exercise, meditation, or talking with loved ones can help.
Remember, BI-RADS 3 is a cautious label, not a diagnosis.
Key Takeaway
So, what percentage of BI-RADS 3 is cancer?
The answer is reassuring — less than 2%.
That means more than 98% of BI-RADS 3 mammogram results are benign. The BI-RADS 3 category is designed to protect patients by monitoring findings that look almost entirely harmless but deserve a little extra attention.
If you’ve received a BI-RADS 3 result, stay calm, follow your doctor’s recommendations, and attend your scheduled imaging. In most cases, these findings remain stable and are eventually cleared as benign.
Final Thoughts
Breast imaging can be stressful, but BI-RADS 3 is one of the least concerning categories. It means your doctor is being careful, not that you have cancer.
Early detection, regular screening, and open communication with your healthcare team are the best ways to protect your breast health. And remember, knowledge is power: the more you understand your mammogram results, the less fearful the process becomes.