Left breast calcification 4a is not necessarily cancer, this classification is based on the severity of the breast to grade, a total of zero to six values the higher the likelihood of suffering from cancer. 4 category to consider a lesion, which is divided into abc three types, 4a belongs to the highest likelihood of benign nodules of a type. Regular follow-up and review is needed, if no abnormal changes are found in two or three consecutive years, it is mostly considered to be benign. If the growth rate is too fast or accompanied by abnormal pain, it is necessary to pay attention to the possibility of malignant changes, and need to take timely surgical treatment, and then also need to carry out pathologic examination to discharge the possibility of cancer. Therefore, calcification 4a in the left breast is not cancer, but has a certain risk of cancer and needs to be paid attention to at any time.