There is no relationship between breast size and breast cancer development, so it is possible to get breast cancer regardless of large or small breasts. For breast cancer patients with large breasts, if it is total excision, it is more difficult to reconstruct, the amount of tissue needed will be larger, and the result may be poor after reconstruction. If the patient does not reconstruct after total excision, the weight of both breasts will be different, and this will cause scoliosis for a long time, but there is no relationship with the incidence of breast cancer. The cause of malignancy is not clear, but it may be related to the following factors: 1) hormone level may be related to breast cancer; 2) heredity. If close relatives, such as mother or aunt, have a family history of breast cancer, they should be examined more diligently than others and detected earlier, because the chance of getting breast cancer is higher than patients without family history.