What is a carcinoembryonic antigen test (CEA)?
A carcinoembryonic antigen (CEA) test is a blood test used to help diagnose and manage certain types of cancers. The CEA test is used especially for cancers of the large intestine and rectum. Your doctor can also use the test results to help determine if a cancer treatment is working.
抗原是一种物质,由癌变tumor cells. Sometimes antigens are released into the bloodstream. The CEA test measures the amount of CEA in the blood. A high amount of CEA in your body after a cancer treatment or surgery suggests the cancer is not gone. It may also mean that the cancer has spread to other parts of your body.
Smoking can increase the amount of CEA in your body even in the absence of cancer. You should tell your doctor if you smoke.
CEA测试有不同的用途。如果您的症状表明您可能会癌症，您的医生可以订购CEA测试。CEA测试可以帮助您的医生了解癌症治疗是否正常。这些治疗可能包括手术，化疗，辐射或全部三种组合。您的医生也可能使用CEA测试，以帮助确定癌症是否在完成后恢复或重复。
在诊断出一种熟知的癌症时，CEA测试最有用。并非所有癌症都会产生CEA。
Increased levels of CEA may be found in the following cancers:
- colorectal or colon cancer
- medullary thyroid carcinoma
- breast cancer
- cancer of the gastrointestinal tract
- liver cancer
- 肺癌
- 卵巢癌
- pancreatic cancer
- prostate cancer
The CEA test isn’t useful for diagnosing or screening the general population for cancer. It’s usually not used to screen or diagnose you if you’re healthy or aren’t showing any symptoms of a disease. But if someone has a familial genetic syndrome for colon cancer then it’s reasonable use CEA as a screening tool. These cases are rare.
如果您诊断患有癌症，您的医生可能开始在开始治疗之前开始监测CEA的水平。这将为您的CEA建立基线水平。单个CEA值通常不会随着时间的数量和这些值的趋势和这些值的趋势。您的医生将在治疗之前，期间和之后反复进行测试以检查变化。
CEA测试是在医生办公室进行的血液测试。血液通常从手臂中的静脉抽出。血液抽取过程或静脉穿刺通常涉及以下步骤：
- A healthcare provider will clean the puncture site with an antiseptic. The site is usually in the middle of your arm, on the opposite side of the elbow.
- 医疗保健提供者将在上臂周围缠绕弹性带，以帮助使静脉充满血液。
- 然后将针插入静脉中以将血液收集到附着的小瓶或管中。
- The band is unwrapped from your arm.
- A laboratory will analyze your blood sample.
与任何血液测试一样，穿孔部位存在出血，瘀伤或感染的风险。当针插入时，可能会觉得中等疼痛或尖锐的刺痛感。
A normal level of CEA is less than or equal to 3 nanograms per milliliter (ng/mL). Most healthy people have levels below this amount.
CEA水平通常会在癌症成功移除后一到四个月恢复正常。
当CEA高于3ng / mL时，会发生升高的CEA水平。这些水平被认为是异常的。具有许多类型癌症的人可以具有高于3 ng / ml的水平。如果您有值高的值，那并不意味着您有癌症。其他原因可能导致高于3 ng / ml的水平。这些可以包括：
- 感染
- cirrhosis
- chronic smoking
- inflammatory bowel disease (IBD)
Levels of CEA higher than 20 ng/mL are considered very high. If you have CEA levels this high and you also have symptoms of cancer, it strongly suggests the cancer has not been removed successfully after treatment. It may also suggest that the cancer has metastasized, or spread, to other parts of your body.
如果您在另外健康的情况下，吸烟可能会影响您的CEA测试结果。CEA通常升高，但吸烟的人中少于5 ng / ml。
CEA水平不应该是用于确定您是否患有癌症的唯一测试。您的医生将使用CEA测试以及其他测试和您的症状评估。您和您的医生可以共同努力，如果您的医生确定您的癌症，请决定您的最佳治疗选择。