Breast Cancer

乳腺癌

Breast cancer most often involves glandular breast cells in the ducts or lobules. Most patients present with an asymptomatic lump discovered during examination or screening mammography. Diagnosis is confirmed by biopsy. Treatment usually includes surgical excision, often with radiation therapy and adjuvant systemic therapy.

乳腺癌大多累及乳腺管或小叶乳腺细胞，多数病人在检查或乳房X线照相时发现一无症状肿块，通过组织活检确诊。治疗通常包括外科切除，常伴以放疗和辅助性全身疗法。

About 203,000 new cases were identified in 2003. It is the 2nd leading cause of cancer death in women (after lung cancer), with about 40,000 deaths in 2003. Male breast cancer accounts for < 1% of total cases; manifestations, diagnosis, and management are the same, although men tend to present later.

2003年确认的新病例有203,000例，它是导致妇女因癌症死亡的第二大原因（仅次于肺癌)，其中有40,000例就死于2003年。男性乳腺癌在全部病例中所占的比例不到1%。虽然男性症状往往出现较晚，但其临床表现、诊断与处理与女性相同。

Risk Factors

危险因素

In the US, cumulative risk of developing breast cancer is 12% (1 in 8) by age 95, and risk of dying of it is about 4%. Much of the risk is incurred after age 60 (see Table 1: Breast Disorders: Breast Cancer Risks). These statistics can be misleading because cumulative risk of developing the cancer in any 20-yr period is considerably lower.

在美国，95岁时患乳腺癌的累积危险率是12%（8个有1个)，死亡危险率约4%。危险多数发生在60岁以后（见表1：乳房疾病：乳腺癌的危险性)。这些统计数字可能使人误解，因为在任一20年期内，乳腺癌的累积危险性都要低得多。

Family history of breast cancer in a 1st-degree relative (mother, sister, daughter) doubles or triples risk of developing the cancer, but history in more distant relatives increases risk only slightly. When ≥ 2 1st-degree relatives have breast cancer, risk may be 5 to 6 times higher. About 5% of women with breast cancer carry a mutation in one of the 2 known breast cancer genes, BRCA1 or BRCA2. If relatives of such a woman also carry the gene, they have a 50 to 85% lifetime risk of developing breast cancer. Women with BRCA1 mutations also have a 20 to 40% lifetime risk of developing ovarian cancer; risk among women with BRCA2 mutations is increased less. Women without a family history of breast cancer in at least 2 1st-degree relatives are unlikely to carry this gene and thus do not require screening for BRCA1 and BRCA2 mutations. Men who carry a BRCA2 mutation also have an increased risk of developing breast cancer. The genes are more common among Ashkenazi Jews.

1级亲属（母亲、姐妹、女儿)若有乳腺癌家族史，则可使癌症危险增加2－3倍，但远亲乳腺癌史对癌症率影响甚微。当≥2个1级亲属有乳腺癌时，危险性可高出5－6倍。约5%的乳腺癌妇女可携带2个已知乳腺癌基因（BRCA1或BRCA2)中的一个，如果这些妇女的亲属也携带该基因，其患乳腺癌的危险率就可达到50－80%。BRCA1基因变异妇女一生中得卵巢癌的危险率为20－40%，BRCA2基因变异妇女的危险率增加较少。无乳腺癌家族史（至少有两个1级亲属没有)妇女不可能携带该基因，因此，也不需要作BRCA1和BRCA2筛查。男性BRCA2携带者的乳腺癌危险性也会增加。这些基因在北欧犹太教徒中更为常见。医学全.在线提供

History of in situ or invasive breast cancer increases risk: Risk of developing cancer in the contralateral breast after mastectomy is about 0.5 to 1%/yr of follow-up.医学全在.线www.med126.com

原位或浸润性乳腺癌史增加癌症危险。乳房切除后，随访病人中对侧乳房的癌症危险率约0.5-1%/年。

Early menarche, late menopause, or late 1st pregnancy increases risk. Women who have a 1st pregnancy after age 30 are at higher risk than those who are nulliparous.

初潮早，停经晚，或首次妊娠晚，均可增加癌症危险。30岁后怀第一胎的妇女，其危险性要高于未产妇。

History of fibrocystic changes requiring biopsy for diagnosis increases risk slightly. Women with multiple breast lumps but no histologic confirmation of a high-risk pattern should not be considered at high risk. Benign lesions that may slightly increase risk of developing invasive breast cancer include complex fibroadenoma, moderate or florid hyperplasia (with or without atypia), sclerosing adenosis, and papilloma. Atypical ductal or lobular hyperplasia increases risk of breast cancer 4- to 5-fold; risk increases to about 10-fold in patients who also have a family history of invasive breast cancer in a 1st-degree relative.

因纤维囊性病变而作活检诊断，有些病史者的危险性略有增加。有多个乳房肿块，但无高危型的组织学确认，不应视为高危性。有些良性病损可增加得浸润性乳腺癌危险，这些病损包括复合纤维腺瘤、中度或鲜红样增生（伴或无异型)、硬化性腺病和乳头状瘤。非典型性乳腺管或小叶增生使乳腺癌危险增加4－5倍，1级亲属有浸润性乳腺癌家族史的病人，其危险性可增加约10倍。

Oral contraceptive use increases risk very slightly (by about 5 more cases per 100,000 women). Risk increases primarily during the years of contraceptive use and tapers off during the 10 yr after stopping. Risk is highest in women who began to use contraceptives before age 20 (although absolute risk is still very low).

口服避孕药者危险性增加很少（每100,000位妇女只增加约5例)。危险性增加主要是在服药期间，在停药后10年间逐渐减少。20岁前开始服用避孕药妇女的得癌危险性最高（尽管其绝对危险率仍然很低)。

Postmenopausal hormone (estrogen plus a progestin) therapy appears to increase risk modestly after only 3 yr of use. With prolonged use, risk is increased by about 7 or 8 cases per 10,000 women for each year of use. Use of estrogen alone does not appear to increase risk of breast cancer. Selective estrogen-receptor modulators (eg, raloxifene) may reduce risk of developing breast cancer.

实施绝经后激素（雌激素＋黄体激素)疗法3年后，危险性稍有增加。延长使用时，每年每10,000名妇女可增加7-8例。只用雌激素似乎不会增加危险。选择性雌激素受体调节物（如雷洛昔芬)可减少患癌危险。

Diet may play a role in causing or promoting growth of breast cancers, but conclusive evidence about the effect of a particular diet (eg, one high in fats) is lacking. Obese postmenopausal women are at increased risk, but there is no evidence that dietary modification decreases risk. For obese women who are still menstruating, risk may be decreased.

饮食在引起或促进乳腺癌生长中起一定作用，但尚无某一特定饮食（如高脂肪饮食)所起作用的结论性证据。绝经后肥胖妇女危险性增加，但没有证据证明改变饮食会降低危险。仍有月经来潮的肥胖妇女，危险可能减少。

Exposure to radiation therapy before age 30 increases risk. Mantle-field radiation therapy for Hodgkin lymphoma quadruples risk of breast cancer over the next 20 to 30 yr.

30岁前接受放疗增加危险。治疗霍杰金淋巴瘤所用的斗篷射野放疗可使其未来20－30年间的乳腺癌危险性增加4倍。