Transcript Tumour Markers

बालस्तवत क्रीडासक्तः तरुणास्तवत तरुणीसक्तः
व्र्द्धस्तावत चिन्तासक्तः परमे ब्रह्मणण कोपपनससक्तः
Balasthavath Kreeda aasaktah
tarunasthaavath taruneesaktah
vriddhasthaavath chintaasaktah
Parame brahmani kopinasaktah
As medical students we were playful & wasted time
As young doctors, were preoccupied with family, spouse
As older docs, we have enough worries, nothing goes in
Alas, when are we to gain an update of our knowledge!!
Aberrant copy or number
Translocations
Deletions
Telomere extensions abnormal
Point Mutations
Microsatellite Alterations
Promoter hypermethylation
Viral DNA incorporation
Point mutations in RNA
Over/under expression of RNA
Transcription miscoding
DNA mutations in mitochondria
Structural alterations in proteins
Changes in enzymatic activity
Mislocalization of protein
Altered protein expression
Genes
De
Novo
Viral
Ca
Radia
tion
Chemi
cals
Inherited : Expression of inherited oncogene
e.g. viral gene incorporated into host gene
Viral: Human papilloma, herpes type 2, HBV, EBV
(DNA) - Human T-cell leukemia virus (RNA)
Chemical:
- Poly cyclic hydrocarbons cause sarcomas
- Aromatic amines cause mammary carcinoma
- Alkyl nitroso amines cause hepatoma
Radiological: Ultraviolet & ionizing irradiation
Spontaneous: Failure in cellular growth control
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Pathological Ca cell masses are formed by
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Abnormal & uncontrolled expansion of clones
of single cell
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Transformation of normal cells to cancer cells
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Spontaneous mutation during daily cell division
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It may be induced by carcinogens (chem, virus)
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Ca cell antigens are different from normal cells
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Recognized and destroyed by immune system
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During neoplastic transformation, new Ag develop
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The host recognizes them as non-self antigens
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Cell mediated immune reactions attack these
non-self tumor cells
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Immune response acts as surveillance system to
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Detect and eliminate newly arising neoplastic cells
This system include :
1. Natural killer (NK) cells
They kill directly tumor cells, helped by Inf, IL-2
2. Cytotoxic T-cells
They also kill directly tumor cells
3. Cell mediated T-cells (effector T-cells)
They produce and release a variety of lymphokines :
a-Macrophage activation factor, activates macrophage
b-Gamma interferon and interleukin-2 that activate NK
c-Tumor necrosis factor (cachectine)
4. B-cells :
- Tumor associated antigens stimulate production of
specific antibodies by host B-cells
- These specific antibodies bind together on tumor cell
surface leading to destruction of tumor through
a- Antibody mediated cytotoxicity
Cytotoxic T-cells kill IgG-coated tumor cells
b- Sensitized T-cells activate macrophages and release
macrophage activating factor
c- IgG-coated tumor cells attacked by macrophages, in turn
d- Activation of classical pathway of complement leading
to lysis of tumor cells
Tumor escape of immune defenses
1. Reduced levels or absence of MHCI molecule
on tumor - they can’t be recognized by CTLs
2. Some tumors stop expressing the antigens
These tumors are called “antigen loss variants”
3. Production of immunosuppressive factors by
tumor e.g. transforming growth factor (TGF-β)
4. Tumor antigens may induce specific
immunologic tolerance by the immune system
5.
Tumor cells have an inherent defect in antigen
processing and presentation
6.
Blocking of receptors on T-cells by specific antigen
antibodies complex (after shedding of tumor Ag)
prevents them from recognizing and attacking
tumor cells
7.
Antigens on the surface of tumors may be masked
by sialic acid-containing mucopolysaccharides
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Immune suppression of the host as in transplant
patients who show a higher incidence of malignancy
• Biological substances synthesized and
released by cancer cells themselves or
• Produced by the host in response to the
presence of tumor
• Most tumor markers are proteins
• Detected in a solid tumor, in circulating
tumor cells in peripheral blood, in serum,
lymph nodes, in bone marrow, or in other
body fluid (urine, stool, ascites)
Glyco/lipoproteins produced by:
 malignant cells
 normal cells in response to tumor
 inflammatory cells and tissues
 found in serum, urine, body fluids
 react with man-made antibodies or
 combine with man-made antigens
 cyto/histocompatibility reaction to form
 cyto/histocompatibility complexes
Screening
Early
Detection
Diagnosis
Monitor
1. Screening
To identify early cancer risk
2. Diagnosis
To corroborate the diagnosis
3. Staging
To assess & stratify the risk
4. Prognosis
To predict the outcome
5. Localization
To locate the primary
6. Therapy
To target the therapy
7. Surveillance
To detect recurrence in F-Up
8. Monitoring
To evaluate response to Rx.
1. Cancer heterogeneity
2. Lack of Specificity – false positives
3. Lack of Sensitivity - false negatives
4. Benign diseases - positive CA 125 or CEA
5. Smokers have raised CEA
6. Normal persons also have small amounts
7. Higher levels only with large tumor volume
8. Some cancers never have higher levels
Antigens
Hormones
TUMOR
Enzymes
Tissue Specific
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Tumour-Associated Proteins (TAP)
Cell membrane receptors
Hormones
Immunoglobulins / Cellular antigens
Polyamines
Protein clusters and fragments
Chromosomal material
Genes (single, clusters)
Genetic material (DNA, RNA, mRNA)
Cell modulators (transducers / suppressors)
1. Viral Antigen :
a- Viral proteins and glycoproteins
b- New antigens produced by virally infected
host cells under control of viral nucleic acid
2. Tumor specific antigens :
- Tumor cells develop new antigens specific to
their carcinogens
3. Tumor specific transplantation antigens :
- Tumor cells express new MHC antigens due to
alteration of normally present MHC antigens
4. Oncofetal antigens:
a- Carcino-embryonic antigens (CEA)
- Normally expressed during fetal life on fetal gut
- Reappearance in adult life:
GIT, pancreas, biliary system and cancer breast
b- Alpha fetoprotein:
- Normally expressed in fetal life
- Reappearance in adult life; hepatoma
A. Hormones :
Human Chorionic Gonadotrophins (HCG) are
secreted in Choriocarcinoma, Ovarian Ca;
Thyroxin is secreted in thyroid cancer
B. Enzymes :
Acid phosphatase in prostate cancer;
Alkaline phosphatase, lipase and amylase
enzymes in cases of cancer of pancreas
• Enzymes (PSA, NSE, VMA, HVA)
• Cell membrane receptors (ER, PR)
• Tumor antigens (CEA, AFP)
• Antibodies (IgA, IgG, IgM, IgD)
• Antigens (p53, ki-62)
• CA-specific proteins(CA 19-9, CA 124)
• Gene mutation products (BR CA 1, 2)
• Tissue-specific proteins (PSA, hCGH)
• Special hormones (b-hCGH, h-CGH)
• Catecholamines (VMA, HVA, ACTH)
• Polyamines
• Cytoplasmic / Nucleic material (DNA)
• Products of cell turn-over (TNF)
• Cellular modulators (ki-62, c-erb-2)
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ELISA
Immuno-histochemistry (IHC)
Polymerase chain reaction (PCR)
Fluorescence in situ hybridization (FISH)
Cluster Kits ( All-in-One Kit)
– Detects profiles
– Patterns
– Prototypes
– Constellations
• Expression of single proteins
• Expression of multiple proteins
• Chip analysis – “All-in-One”
• Expression of protein profiles
(Proteonomics)
• Gene methylation at DNA level
• Genes / mutations (Genomics)
• G-scan (genome ID scan)
1. hCGH
(specific)
9. CA-15-3 (NS)
2. beta-hCGH (specific)
10. CA-19-9 (NS)
3. CEA
(NS)
11. CA-72-4 (NS)
4. AFP
(NS)
12. CA-27.29 (NS)
5. Bence-Jones (MM)
13. CA-125
(NS)
6. Beta-2-M (S)
14. ER / PR (Breast)
7. BTA (Bladder) (S)
15. HER-2 neu (c-erbB-2)
8. CgA (Chromogranin-A)
16. BR CA-1 / BR CA-2
1. LASA-P (S)
9. Alk. p’tase (mets)
2. NM-22 (S)
10. Alpha Amylase
3. PSA (Prostate-S)
11. SIADH, ACTH, ADH
4. PSMA (Prostate-S)
12. GT-II (NS)
5. S-100 (Melanoma)
13. VMA, HVA (S)
6. TA-90 (NS)
14. Polyamines (NS)
7. TgA, IgA, D, G, M
15. Genes (k-ras, ki-62)
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16. Chromosome (p53)
TPA (NS)
• Prostate Specific Antigen(PSA) is a glycoprotein
• Ideal as a tumor marker, high tissue specificity
• High sensitivity for prostate cancer
• Also elevated in BPH & prostatitis
• Useful in
– Dx. & follow up of prostate Ca, Prognostic factor
– To monitor recurrence & response to treatment
– ? For screening of prostate cancer along with DRE
• Free PSA：PSA not bound to the plasma anti
proteases α1-antichymotrypsin & α2-macroglobulin
– An ↑in ratio of free/total PSA is associated with
increased probability of prostate cancer
– 97% specificity, 96% sensitivity for prostate Ca
– For population screening and diagnosis an increase
of 0.75 ng/ml per year in any given patient has high
sensitivity and specificity for prostate cancer vs BPH,
especially when combined with DRE and TRUS
• 80% of non mucinous ovarian cancer detected
by the monoclonal antibody to CA-125
• Elevated in Ovarian, Endometrial, Pancreatic,
Lung, Breast, Colon cancers and also in
• Menstruation, Pregnancy, Endometriosis and
other gynecological and non gynec conditions.
• Useful in monitoring ovarian Ca recurrence & Rx.
• Screening of high risk population (BRCA1-2
Carriers); Not useful for routine screening
– Cell surface glycoprotein, present during embryonic
development of coelomic epithelium & is present in
adult structures derived from it
– For follow up, an increase may predict recurrent
disease, precedes clinical recurrence by months
– >80% of epithelial ovarian cancer, cell types：
serous > endometriod, clear cell > mucinous
– Correlates with tumor bulk,
– In Endometriosis most common
–  levels also found in PID, 1st trimester
• Alfa Feto Protein is a serum fetal protein synthesized by
the liver, yolk sac, gastrointestinal tract – a glycoprotein
• In Hepatocellular Cancer: It is diagnostic (>500) and also
useful for screening of high risk population (HBV, HCV)
• Benign conditions: hepatic parenchymal inflammation,
hepatic necrosis, pregnancy, primary biliary cirrhosis,
extra hepatic biliary obstruction give positive test.
• Testicular germ cell tumor (embrional or endodermal):
• Diagnosis, Prognosis, to monitor recurrence & response
• The absolute AFP level correlates with tumor bulk
• Cancers of pancreas, colon, stomach & bronchogenic Ca
• Complex glycoprotein that is associated with the
plasma membrane of tumor cells, from which it
may be released in to the blood
• Elevated specially in Colon cancer, Adeno. Ca uterus
• Normal pre Rx CEA indicates no metastasis
• Also in Pancreatic, Gastric, Lung, breast & Ovarian Ca
• Also in cirrhosis, inflammatory bowel disease, chronic
lung disease, pancreatitis, fibrocystic breast disease
• 19% of smokers, 3% of healthy population
• Not satisfactory for screening for a healthy population
• Good for monitoring recurrence & to monitor Rx.
CA 19-9 is elevated in
• In 21-42% patients of gastric Ca
• In 20-40% patients of colonic Ca
• In 71-93% patients of pancreatic Ca
• For DD of benign from malignant disease
• Dx, FU, Relapse, 70% specificity & 90% sensitivity
– It is a mucin, does not  during pregnancy
– Monitor patients who do not express CA 125,
mucinous (76%) > serous (27%)
• Human chorionic gonodotropin (βHCG)
– Glycoprotein synthesized by syncytio trophoblastic
cells of normal placenta
– Serum and urine HCG ↑ in early gestation and peak
in the first trimester (60~90 days)
– Elevated in Gestational trophoblastic disease (a
progressive rise in after 90 days of gestation →
highly suggestive), choriocarcinoma
– Elevated in testicular cancer, βHCG after surgery
– Monitor treatment response, relapse & recurrence
Estrogen Receptor (ER)
– 2 isoforms：ERa and ERb
– ERa → better prognosis, predictor of relapse
– useful when deciding on adjuvant hormone
treatment
– As diagnostic marker when it is a primary
unknown tumor
– ERb → Good prognostic factor, correlates with
low grade and negative axillary LN status
• HER-2/neu oncogene (using monoclonal
antibody) - over expression related to poor
prognosis in breast cancer
• Oncogene c-erbB-2 gene：over expressed in
30% of breast cancers, correlation between
c-erbB-2 gene positivity, positive axillary node
status, reduced time to relapse and reduced
overall survival
• BRCA1 gene on chromosome 17q：familial
breast-ovarian cancer syndrome, and breast
cancer in early-onset breast cancer families →
high risk screening
- To monitor Rx. & to detect recurrence BR Ca
– ↑ in 20% with localized breast cancer, ~80% with
metastatic disease, esp. if with bone involvement
– Specificity of 86%, sensitivity of 30%
– Also ↑ in gastric, pancreatic, cervical & lung cancer
– c-erbB-2 overexpression should be evaluated on
every primary breast cancer either at the time of
diagnosis or at the time of recurrence.
• Tyrosinase
– Use RT-PCR to detect hematogenous spread of
melanoma cells from a solid tumor in peripheral
blood
• S100B protein
– For confirmation of amelanotic malignant
melanoma by immunohistology
– ↑in 70% with stage IV metastasized melanoma
• MIA (melanoma inhibitory activity)
– Preoperative: 59% at stage III, 89% at stage IV
• Thyroglobulin
– Tissue-specific, glycoprotein produced by thyroid
follicular cells
– Also increased in breast or lung cancer
• Thyrocalcitonin
– From thyroid C cells & medullary thyroid cancer
– Effective to screen patients with 1st degree
relatives affected by medullary thyroid cancer
and multiple endocrine neoplasia type 2 (MEN2)
• Burkitt’s type lymphoma and leukemia
– T (8;14) due to juxtaposition and activation of the cmyc gene
• CD 25 most sensitive serum marker for tumor burden
• CD 44 high concentration indicates poor prognosis
• Lactate dehydrogenase (LDH)
– Normal: 100~250 IU/L
– High-grade lymphomas, blood levels correlate closely
with disease activity and response to therapy
• Neuron-specific enolase (NSE)
– A neuronal isoenzyme of cytoplasmic enzyme
enolase, in neuroendocrine cells
– As a prognostic factor in neuroblastoma
– Occurs in neuroendocrine tumors: medullary
carcinoma of the thyroid, pheochromocytoma,
carcinoid tumors; immature teratoma, small cell
carcinoma of lung, non-small-cell cancer,
melanoma. Correlate with stage and bulk of disease
• N-myc oncogene in neuroblastoma N-myc copy
number is associated with stage and prognosis
• Expressed only in tumor cells
• Example: an oncogene is translocated and fused
to an active promoter of another gene → fusion
proteins → constant active production →
development of malignant clone
• Philadelphia chromosome in CML, t(9;22)
• (q34;q11) bcr/abl translocation
• t(8;21) acute non-lymphocytic leukemia,
• t(15;17) in APL
• Hematological malignancies
• Abnormal Chromosome
• Due to translocation
• t (9;22) – Ph short Chrom
• bcr/abl fusion gene
• This takes place in a single
bone marrow cell
• Creating fusion proteins
• Detected by FISH technique
• Philadelphia chromosome
in ALL - poor prognosis
• Genomics – Gene structure
• Proteonomics – Protein structure
• Pharmacogenomics
– Gene-based drugs structuring and delivery
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G-scan – Human genome mapping
New treatment modalities
Individualised treatment modalities
Early detection of malignant change
Greater sensitivity and specificity
Better monitoring and follow-up care
1. Alpha fetoprotein antigen (AFP) in hepatoma
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Carcino-Embryoinic Antigen (CEA) in GI tumors
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CEA in tumors of biliary system and cancer breast
4. Cancer Antigen 125 (CA 125) in ovarian carcinoma
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Cancer Antigen 15-3 (CA15-3) in breast cancer
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Cancer Antigen 19-9 in colon and pancreatic tumor
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Prostatic specific antigen (PSA) - prostatic tumors
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