病理组织学检查是诊断癌前病变的最可靠标准。目前公认的癌前病变有: （1）小叶及导管不典型增生; （2） 柱状上皮不典型增生; （3） 小叶原位癌; （4） 乳头状病变;（5） 异常增生放射状瘢痕。治疗癌前病变的最有效方法是手术切除。但是必须权衡手术范围与外形美观之间的矛盾，既不要切除范围过大，造成不必要的组织缺失，也不要切除范围过小而留下复发隐患。导管原位癌是乳腺癌的早期阶段，但是，纯粹的导管原位癌不具有侵袭性，被看作癌前病变和癌的中间状态。手术切除、放疗加降低风险的内分泌治疗是导管原位癌主要治疗方法。

Treatment of breast cancer and precancerous lesions WANG Shu, ZHANG Jia-qing, CAO Ying-ming. Breast Disease Center, Peking University People?s Hospital, Beijing 100044, China Abstract Up to now, pathological diagnosis is the final decision for precancerous lesions, and surgery is the most effective management. There is a particular dilemma for surgeons, who must balance the risk of resecting too much and causing unnecessary cosmetic damage, or resecting too small and leaving an increased risk of recurrence. Ductal carcinoma in situ(DCIS) is the intermediate stage between precancerous lesions and invasive breast carcinoma, surgery, radiotherapy and risk reduction endocrinotherapy have become the main treatment for DCIS.