概述
非典型增生是一种累及乳腺细胞的癌前状况。非典型增生是指乳房的乳管和小叶中异常细胞的堆积。
非典型增生不是癌症，但会增加罹患乳腺癌的风险。终身来看，如果非典型增生细胞在乳管或小叶中堆积而且异常程度加剧，就有可能转化为非浸润性乳腺癌（原位癌）或浸润性乳腺癌。
如果被诊断为非典型增生，那么日后罹患乳腺癌的风险会增加。为此，医生经常建议加强乳腺癌筛查并进行药物治疗，以降低患乳腺癌的风险。
症状
非典型增生通常不会引起任何特殊症状。
何时就医
如果有任何体征或症状令您担心，请与医生约诊。
非典型增生通常是在乳房活检时发现的，活检是为了查看乳腺 X 线摄影或超声检查中发现的异常。有时，非典型增生是在为检查乳腺问题（如肿块或乳头溢液）而进行的活检中发现的。
病因
导致非典型增生的原因目前尚不清楚。
乳腺细胞在数量、大小、形状、生长模式和外观上出现异常时，就会出现非典型增生。非典型增生的类型取决于异常细胞的外观：
- 非典型导管增生是指乳导管内的异常细胞。
- 非典型小叶增生是指乳腺小叶内的异常细胞。
非典型增生被认为是可能积聚并演变成乳腺癌的复杂细胞转变的一部分。乳腺癌的演变过程通常包括：
- 增生。起初，正常细胞的发育和生长受到干扰，进而导致外观正常的细胞过剩（增生）。
- 非典型增生。多余的细胞堆叠在一起，开始呈现出一种不正常的外观。
- 非浸润性（原位）癌症。这些异常细胞在外观上继续发展和增殖，演变成原位癌，此时癌细胞仍然局限于乳导管。
- 浸润性癌症。异常细胞在乳导管内积聚，继续增殖并转变为癌细胞。浸润性癌症往往会侵入周围的组织、血管或淋巴通道。
风险因素
There are no specific risk factors for atypical hyperplasia of the breast. Atypical hyperplasia is one of several conditions that cause a growth of cells in the breast that isn't cancerous. These conditions are sometimes called benign breast diseases. Healthcare professionals have found risk factors for benign breast diseases. They include:
- A family history of breast cancer. If a parent, sibling or child had breast cancer, your risk of being diagnosed with atypical hyperplasia of the breast or another benign breast disease before menopause is increased.
- Menopausal hormone therapy. Taking certain hormone therapy medicines to control the symptoms of menopause may increase the risk of atypical hyperplasia and other benign breast diseases.
并发症
如果被诊断为非典型增生，则日后患乳腺癌的风险较高。非典型增生女性患者患乳腺癌的风险比无增生的女性约高四倍。非典型导管增生女性患者和非典型小叶增生女性患者患乳腺癌的风险相似。
研究非典型增生女性患者的研究人员发现，患乳腺癌的风险随着时间的推移而增加：
- 大约 7% 的非特异性增生女性患者在诊断后第 5 年可能罹患乳腺癌。换句话说，在每 100 例确诊为非特异性增生的女性中，预计有 7 例会在诊断后五年内出现乳腺癌。93 例不会被诊断乳腺癌。
- 大约 13% 的非特异性增生女性患者在诊断后第 10 年可能罹患乳腺癌。即在每 100 例确诊为非特异性增生的女性中，预计有 13 例会在诊断后 10 年内患上乳腺癌。87 例不会出现乳腺癌。
- 大约 30% 的非特异性增生女性患者在诊断后第 25 年可能罹患乳腺癌。换句话说，在每 100 例确诊为非特异性增生的女性中，预计有 30 例会在诊断后 25 年内发展出乳腺癌。70 例不会出现乳腺癌。
请与医生讨论您罹患乳腺癌的风险。知悉自己患乳腺癌的风险可以帮助您决定是否进行乳腺癌筛查和接受降低风险的药物治疗。
预防
It's not clear whether there's anything that can prevent atypical hyperplasia of the breast. The same things that help lower the risk of breast cancer may help lower the risk of atypical hyperplasia. Things you can do to lower your risk of breast cancer include:
Ask about breast cancer screening
Talk with your doctor or other healthcare professional about when to begin breast cancer screening. Ask about the benefits and risks of screening. Together, you can decide what breast cancer screening tests are right for you.
Become familiar with your breasts through breast self-exam for breast awareness
You may choose to become familiar with your breasts by occasionally inspecting them during a breast self-exam for breast awareness. If there is a new change, a lump or something not typical in your breasts, report it to a healthcare professional right away.
Breast awareness can't prevent breast cancer. But it may help you to better understand the look and feel of your breasts. This might make it more likely that you'll notice if something changes.
Drink alcohol in moderation, if at all
Limit the amount of alcohol you drink to no more than one drink a day, if you choose to drink. For breast cancer prevention, there is no safe amount of alcohol. So if you're very concerned about your breast cancer risk, you may choose to not drink alcohol.
Exercise most days of the week
Aim for at least 30 minutes of exercise on most days of the week. If you haven't been active lately, ask a healthcare professional whether it's OK and start slowly.
Limit menopausal hormone therapy
Hormone therapy treatments used to ease menopause symptoms may increase the risk of breast cancer. Talk with a healthcare professional about the benefits and risks of hormone therapy.
Some people have symptoms during menopause that cause discomfort. These people may decide that the risks of hormone therapy are acceptable to get relief. To reduce the risk of breast cancer, use the lowest dose of hormone therapy possible for the shortest amount of time.
Maintain a healthy weight
If your weight is healthy, work to maintain that weight. If you need to lose weight, ask a healthcare professional about healthy ways to lower your weight. Eat fewer calories and slowly increase the amount of exercise.