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Tumour marker: Difference between revisions

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(Created page with "<section begin="pathology" />A '''tumour marker''', also called a '''cancer biomarker''', is a substance found in the body which concentration in the blood or other body fluid increases when cancer is present. The tumour marker may be produced by the cancer cells themselves or by healthy cells in response to the cancer. Tumour markers are usually proteins and are often produced in small amounts even in people without cancer. The term tumour marker may also be used to...")
 
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<section begin="pathology" />A '''tumour marker''', also called a '''cancer biomarker''', is a substance found in the body which concentration in the blood or other body fluid increases when [[cancer]] is present. The tumour marker may be produced by the cancer cells themselves or by healthy cells in response to the cancer. Tumour markers are usually proteins and are often produced in small amounts even in people without cancer. The term tumour marker may also be used to mean typical molecular changes in cancers, like ALK rearrangement and overexpression in [[Lung cancer|NSCLC]].
<section begin="clinical biochemistry" /><section begin="pathology" />A '''tumour marker''', also called a '''cancer biomarker''', is a substance found in the body which concentration in the blood or other body fluid increases when [[cancer]] is present. The tumour marker may be produced by the cancer cells themselves or by healthy cells in response to the cancer. Tumour markers are usually proteins and are often produced in small amounts even in people without cancer. The term tumour marker may also be used to mean typical molecular changes in cancers, like ALK rearrangement and overexpression in [[Lung cancer|NSCLC]].


Tumour markers are not used for diagnosis of cancer, as they are not specific (can be elevated even without cancer) and are not sensitive (not all cancers cause tumour marker elevation). Some are used for screening, the prototypical example being PSA for prostate cancer, but because of the low specificity and sensitivity, this is controversial.
Tumour markers are not used for diagnosis of cancer, as they are not specific (can be elevated even without cancer) and are not sensitive (not all cancers cause tumour marker elevation). Some are used for screening, the prototypical example being PSA for prostate cancer, but because of the low specificity and sensitivity, this is controversial.
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|'''Carcinoembryonic antigen (CEA)'''
|'''Carcinoembryonic antigen (CEA)'''
|'''Carcinomas of colon, pancreas, lung, stomach, heart'''
|'''Colorectal cancer, pancreatic cancer, lung cancer, stomach cancer,'''
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|'''Prostate specific antigen (PSA)'''
|'''Prostate specific antigen (PSA)'''
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PSA is sometimes used for screening for prostate cancer, but this is controversial. Screening decreases mortality from prostate cancer but also causes overtreatment, as many of those who will receive cancer therapy (with all the complications and side effects it causes) due to detection of prostate cancer on screening would never have developed a clinically significant cancer.
PSA is sometimes used for screening for prostate cancer, but this is controversial. Screening decreases mortality from prostate cancer but also causes overtreatment, as many of those who will receive cancer therapy (with all the complications and side effects it causes) due to detection of prostate cancer on screening would never have developed a clinically significant cancer.
== Alpha-foetoprotein ==
Alpha-foetoprotein (AFP) is a major plasma protein during foetal development, thought to be the foetal analogue of adult [[albumin]]. It is a tumour marker of several cancers, including [[hepatocellular carcinoma]] and non-seminoma [[testicular cancer]].
== Carcinoembryonal antigen ==
Carcinoembryonal antigen (CEA) is a tumour marker which is primarily associated with gastrointestinal cancers, including colorectal cancer, but can also be elevated in others like lung cancer and breast cancer. For unknown reasons, smokers have elevated CEA levels. CEA can also be elevated in benign gastrointestinal disorders like [[inflammatory bowel disease]]. Approximately 20% of colorectal cancers do not give elevated CEA.<section end="clinical biochemistry" />
[[Category:Pathology]]
[[Category:Laboratory Medicine]]