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? 1. Screening and early detection of cancer 2. Diagnosing cancer 3. Advanced cancer 4. Determining prognosis for certain cancers 5. Seeing if certain treatments are likely to work 6. Seeing how well treatment is working 7. 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 colorectal 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 conditions  thyroid 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 cancer  lung, pancreatic, breast, liver, and colon, cancer in the past ovarian cancer is arather rare disease  increased 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 cancer  lung, breast,melanoma, lymphoma, thyroid, pancreas, liver, stomach, kidney, prostate, ovary, cervix, bladder non-cancerous diseases  hepatitis,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 cancer  stomach, 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 cancer  breast, bladder, brain, colon, prostate

The End