在乳癌患者中具有乳癌家族史 ,40岁以下以往患过乳癌的年轻病例中 ,对侧乳腺发病的危险性比一般高 5～ 6倍 ,双侧乳癌的发病倾向大。即使没有这种危险因素存在 ,临床也常见双侧发病以及单侧多发。这样的多发乳癌也可能存在着某种其它的发病因素。在所发生的乳癌中也许存在着某 In breast cancer patients with a family history of breast cancer, breast cancer in patients younger than 40 years old in the past, the risk of contralateral breast 5 to 6 times higher than normal, the incidence of bilateral breast cancer tend to be large. Even without the presence of this risk factor, clinical onset is also common bilateral and unilateral multiple. Such multiple breast cancer may also have some other risk factors. There may be something in the breast that has taken place