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Tumor Markers. American cancer society British Journal of Cancer By B.Heidari. What are tumor markers?. substances that can be found in the body when cancer is present Classic : protein in the blood in higher than normal
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Tumor Markers American cancer society British Journal of Cancer By B.Heidari
What are tumor markers? • substances that can be found in the body when cancer is present • Classic : protein in the blood in higher than normal • Some : in urine or other body fluid others are found in tumors and other tissue • Most tumor markers are proteins, but some newer markers are genes or other substances. • In one type of cancer-in many types of cancer
Sample : blood-urine-piece of the tumor • Tumor markers alone are rarely enough to show that cancer is present ! • tumor markers -> patient’s history, physical exam, other lab tests or imaging
How are tumor markers used? • Screening and early detection of cancer • Diagnosing cancer • Advanced cancer • Determining prognosis for certain cancers • Seeing if certain treatments are likely to work • Seeing how well treatment is working • Looking for recurrent cancer
Specific tumor markers The tumor markers listed here are available to most doctors and have reliable scientific information showing that they are useful.
CA 19-9 • was first developed to detect colorectal cancer • most often used in : pancreatic cancer • In very early disease the level is often normal, so it’s not good as a screening test • Still, it’s the best tumor marker for following patients who have cancer of the pancreas. • Normal blood levels below 37 U/mL • elevated in cancer bladder – colorectal – stomach - bile ducts • non-cancerous conditionsthyroid disease, rheumatoid arthritis, inflammatory bowel disease, and pancreatitis
CA 125 • standard tumor marker used to follow epithelial ovarian cancer • Normal blood levels below 35 U/mL • More than 90% of advanced ovarian cancer have high levels. • Levels are also elevated in about half of women whose cancer has not spread outside of the ovary screening test • Trouble : miss many early cancers & problems other than ovarian cancer(uterine fibroids or endometriosis) • elevated in cancerlung, pancreatic, breast, liver, and colon, cancer in the past • ovarian cancer is arather rare diseaseincreased CA-125 level something other than ovarian cancer.
CEA • (Carcinoembryonic antigen) • CEA is not used to diagnose or screen for colorectal cancer, but it’s the preferred tumor marker to help predict outlook. • Normal blood levels below 5.5 ng/mL • standard marker :responding to treatment, recurrency • elevated in cancerlung, breast,melanoma, lymphoma, thyroid, pancreas, liver, stomach, kidney, prostate, ovary, cervix, bladder • non-cancerous diseaseshepatitis,COPD, colitis, rheumatoid arthritis, and pancreatitis, healthy smokers
HER2 • (or HER2/neu, erbB-2, or EGFR2) • is a protein that tells some cancer cells to grow • Elevate in breast cancer cells in about 1 out of 5 people with breast cancer • elevated in cancerstomach, esophagus • Sample:tissue • HER2-positive:grow and spread faster than other cancers -> respond to drugs that work against the HER2 receptor • All newly diagnosed breast cancers and advanced stomach cancers should be tested for HER2
P53 • (BCC7; LFS1; TRP53 ) • nuclear phosphoprotein functions as tumor suppressor by inhibiting cell proliferation • dominant role in cellular apoptosis • P53 gene mutations : 50% of all types of cancers • Commonly :primary breast , colon, ovarian, lung, and esophageal carcinomas
Ki-67 • cancer antigen that is found in growing, dividing cells but is absent in the resting phase of cell growth • a good response to chemotherapy • sample :tumor tissue • high levels : aggressive tumor and predict a poor prognosis , the risk of recurrence • elevated in cancerbreast, bladder, brain, colon, prostate