Tumor marker Tumor: Cancer is abnormal cell growth with the potential to invade or spread toother parts of the body. Biomarker:Measured and evaluated as indicator ofnormal biological process or a pathogenic process, or a pharmacologicalresponse to a therapeutic intervention. Characteristic of Ideal biomarker expression should significantly increase in disease condition Readily quantifiable in clinical sample It should be economically viable Tumor marker It is aBiochemical substances produced by cancer cell or by the healthy cell It’s a Substances found at higher level than normal level in cancerous condition, which differentiatethe normal cell from cancer cells Tumor marker seen in: Blood circulation, Body cavity fluidsCell membrane, Cell cytoplasmTumormarker classification : i. TumorSpecific Antigens -Specific forsingle individual tumor, present only in tumor cells Ex:CEA,CA19-9,CA125 ii.
Tumor-AssociatedAntigens are Found with different tumor of same tissue type Presenton tumor cells and some normal cells Expressed at abnormal concentration whenpresence of cancer Ex: Prostate specific antigen, Beta HCG,AFP L3,thryglobin iii. Enzyme- 1stgroup identified as a biomarker ex:ALP iv. Hormone usedto detect and monitor the cancer ex:ACTH v. Onco-fetalprotein -anti-sera against cancer ex:AFP,CEA,PSA vi.
Tissue cellsurface antigen- Blood group Ag using monoclonal antibody detect cancercell ex: CA 125,CA15-3,CA19-9According tosite tumor marker classification:a. Biochemical /serological marker: b. detected in blood or body fluidsc. histochemical/ tissue marker- found in tissue byimmunological testd. diagnostic markere. prognostic marker/ predictive markerf. therapeutic marker clinical use : Screening diagnosis prognosticpredictor clinicalstaging of the cancerous condition monitoringduring treatment early detection for recurrence CHARACTERISTICSOF AN IDEAL TUMOUR MARKER Should not be very costly sensitivity, Specificity accuracy Precision simple to use Tumor markers:CEA (carcino embryonic antigen)–Lungcancer, breast cancer, Colorectal canceralfa feto protein -Hepato cellular carcinoma, Germ cell tumor, HCG(human chorionic gonodotrophin)humanchorionic gonodotrophin(HCG)- Germinal cell tumor of testis, Ovarian adenocarcinoma,Hepatoma, chorio carcinoma CA 125- Ovariancarcinomacalcitonin – Medullary thyroid cancer CA15-3/ CA27.
29 – Breastcancer, Liver cancer, colon cancer, ovarian endometrial cancer Prostate specific antigen -Prostate cancer Thyroglobulin –Thyroid cancer 21-Genesignature(oncotype-Dx), 70-Gene signature(mammaprint) & Estrogenreceptor/ progesterone receptor -Breast cancer Cytokeratin fragments21-1- Non smallcell Lung cancer,breast cancer,Insulin-Insulinoma(betacell tumor)Cortisol/ACTH- Equine pars intermedia adenoma, adreno corticaltumorBeta 2microglobulin(B2M) -multiple myeloma,Chroniclymphocytic leukemia PTHrP- Adenocarcinoma ofanal sac,lymphoma Chromogenin A(CgA) /parathyroid secretory protein sex steroidhormone-Adeno carcinomaHE4 -Ovarian cancer CD20- Non-hodgkinlymphoma Prostaticacid phosphate – Prostate cancer,myeloma Thymidine kinase – Breast cancer,Nonhodgkin’s lymphoma,Multiple myelomaALP- Metastatic bone,liver,lung,ovary, uterus cancer Methods of detection of tumor marker: I. Immunologicalmethod: Immuno histochemistry Radioimmuno assay ELISA II. Cytogeneticanalysis Fluorescent insitu hybridization(FISH) Spectral karyotyping Comparative genomic hybridization III. Geneticanalysis Sequencing Gel electrophoresis IV.
proteomics Surface enhanced laser desorption/ionizationIMMUNOHISTOCHEMISTRY- By linking the antibodies to a dye, The immunoreactivity between the tissue specimensand antibodies can be visualized with the light microscope