Mod 2 Tumor Makers Flashcards
Substances, usually proteins, that are produced by the body in response to cancer growth or by the cancer tissue itself
Tumor markers
Specimens used in tumor markers:
Blood serum
Urine - VMA
Body tissues - estrogen receptors and progesterone receptors
Characteristics of an ideal tumor marker:
Detectable only in one tumor
Highly specific
Characteristics of an ideal tumor marker:
Non detectable in physiological or benign dse state, to avoid false positive results
Highly sensitive
Characteristics of an ideal tumor marker:
Sufficient time for alteration of natural course of dse
Long lead time
Characteristics of an ideal tumor marker:
Prognostic and predictive utility of tumor, accurately reflecting any tumor progression or regression
Levels correlate with tumor burden
Characteristics of an ideal tumor marker:
Acceptabtability by target population
Easily obtainable specimens
Characteristics of an ideal tumor marker:
Applicability as screening test at mass level
Simple and inexpensive test
Characteristics of an ideal tumor marker:
Frequent serial monitoring of marker levels after 5-6 half lives
Short half life
True or false. In reality, an ideal tumor marker does not exist.
True
Patients were considered to have SLE, if ____ of the criteria were met sequentially or simultaneously during any interval of observation.
Four
Normal fetal proteins synthesized by the liver, yolk sac and GIT
Shares common homology with albumin
Following birth, it clears rapidly from the circulation, having a half life 3.5
Oncofetal antigen
Involved in regulation of cell cycle and become over expressed or mutated almost exclusively in neoplasm
Occurs in epithelial cells and become elevated in tissue and serum in adeno squamous and squamous cell carcinomas
Oncoproteins
Recently discovered patterns of protein expression in serum that appear to be unique to specific types of cancer
Biomarkers for early tumor detection
Proteomics
Serum markers are frequently used in:
Screening
Diagnosis
Predict behavior of cancer
Provides a useful measurement of Ag-Ab concentration
ELISA
Advantages of serum testing over tissue based methods:
Non invasive
More accurate quantification
Lack of inter observer difference
A chymotrypsin like enzyme that occurs almost uniquely in prostate gland and has exceptional use in screening and monitoring in pts being treated for this dse
PSA
Suppress cell growth by arresting it in cell cycle or by apoptosis
P53, BRCA1, BRCA2
Tumor
Adhesion molecules that regulate metastasis:
Integrins
Selectins
Cadherin
Molecules of Ig gene families
Focus on only a small surface area, an epitope or antigenic determinant using monoclonal antibodies
Monoclonal antibody defined tumor markers
Identify Monoclonal antibody defined tumor marker:
Ovarian carcinoma
CA125
Identify Monoclonal antibody defined tumor marker:
Pancreatic Ca
CA 19-9
Identify Monoclonal antibody defined tumor marker:
Breast carcinoma
CA 15-3
HER2/neu
Identify Monoclonal antibody defined tumor marker:
Gastric carcinoma
CA 72-4
Other markers:
Elevates when benign tumor becomes malignant and metastasizes
Hormones
Ectopic tumor markers:
GI, renal, bladder and ovarian ca
Alpha fetoprotein
Ectopic tumor markers:
Endocrine tumors; lung, breast and ovary carcinoma
Calcitonin
Ectopic tumor markers:
Colorectal carcinoma and pancreatic endocrine tumors
Free alpha hCG
Ectopic tumor markers:
Differentiated thyroid carcinoma
Thyroglobulin
