Tumor Markers

American cancer societyBritish 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 cancer2. Diagnosing cancer3. Advanced cancer4. Determining prognosis for certain

cancers5. Seeing if certain treatments are likely to

work6. Seeing how well treatment is working7. 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 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

The End