No. Dense breast tissue is a sort of disclaimer since mammography may not be as reliable for cancer screening in affected people. In contrast, birads is a classification for specific abnormalities seen on mammograms which help guide our decisions for the "next step" in the work-up of this specific abnormality, ie, biopsy, short-term follow up, ultrasound, etc.
Yes for BIRADS 4. A bi-rads 4 results means suspicious for cancer. This result should prompt either a biopsy or other imaging tests. A bi-rads 3 results means "on the fence". Usually a follow-up breast imaging test is done within 6 months to a year. To see the categories and their meaning: http://www. Birads. At/kategorien. Html.
You are mixing up. The classifications. BIRADS is an assessment of suspicion, 1 (normal) through 5 (highly suggestive of malignancy). It has nothing to do with breast density. By law you must be informed of your mammo results within 30 days. Breast density was previously assessed 1 (Fatty) through 4 (very dense), now changed to A through D because of BIRADS confusion. Some states require density notification as well.