2. Tumor markers are the substances that can be
detected in higher than normal amounts in the
serum, urine, nipple aspirate fluid or tissues of
patients with certain types of cancer
Poduced either by cancer cells themselves or by
the body as a response to the cancer.
3. Tumor markers are indicators of cellular,
biochemical, molecular or genetic
alterations by which neoplasia can be
recognized.
A substance, released in to the circulation
by tumor tissue, whose detetion in the
serum indicates the presence of tumor.
4. Three defining characteristics
1. Expressed exclusively by the tumor
2. Collection of specimen for the tumor
marker assay is easy
3. The assay itself is
Reproducible
Rapid
Inexpensive
Currently there is no one tumor marker fulfills all these criteria
5. Diagnostic
Distinguish benign from malignant disease
Correlate with the amount of tumor
(Tumor burden)
Allow subtype classification
Allow accurate staging
Prognostic
Guide choice of therapy
Predict response to therapy
7. Protein tumor markers
First type of tumor markers identified
Called as classic tumor markers
Poor sencitivity & specificity
Serum/plasma concentrations correlate
with tumor burden as they are shed from
the expanding neoplasm.
8. DNA Base tumor markers
Single nucleotide polymorphisms (SNPs)
Chromosomal translocations bcr-abl 9:22 (philadelphia) (CML)
Changes in DNA copy number
Microsatellite instability
Epigenetic changes (e.g., differential promotor region methylation
RNA Based markers
Overexpressed/ underexpressed transcripts
Regulatory RNA (e.g., micro-RNA
11. Tumor marker Cancer Non-neoplastic
condition
Prostate specific antigen
(PSA)
Prostate cancer Prostatis
Prostatic hypertrophy
Neuron – specific enolase Small cell cancer of lung
Neuroblastoma
Lactate dehydrogenase Lymphoma
Ewing’s Sarcoma
Hepatitis
Hemolytic anemia
Many others
12. Tumor marker Cancer Non-neoplastic conditions
Prostate specific antigen Prostatic cancer Prostatitis
Prostatic hypertrophy
Monoclonal immunoglobulin Myeloma Infection
MGUS
CA – 125 Ovrian cancer
Some Lymphomas
Menstruation
Peritonitis
Pregnancy
CA – 19-9 Ca Colon
Ca Pancreas
Ca Breast
Pancreatitis
Ulcerative colitis
CA 15-3 Ca Breast
Ca 72-4 Ca stomach
CD 30 Hodgkin’s disease
Anaplastic large cell lymphoma -
CD 25 Hairy cell leukemia
13. Most studied tumor marker
Onco-fetal protein
Normally present during fetal life
Low concentrations in healthy adults
Structurally
• Glyco-protein
• Molecular weight – 200 kd
• Component of the glycocalyx in cell membrane, located on the luminal
side of the normal intestinal epithelial cells
14. Secreted in to the circulation
Found in mucous secretions of
Exact function unknown
Involved in inhibition of apoptosis
• By anchoring the cell to the ECM
Stomach
Small intestine
Biliary tree
15. Testing Immunoassay
Normal serum levels
• Non smokers 0.0 to 3.4 ng/ml
• Smokers 5 ng/ml
Borderline
2.5 ng/ml – 5 ng/ml
• Benign disorders
Inflammatory bowel disease
Pancreatitis
Cirrhosis
COPD
Elevated >5 ng/ml
• Carcinome colon, pancreas, lung, breast, ovary
• 75 % of the patients with recurrent colo rectal cancers elevate CEA levels before developing
the symptoms
16. Screening
low sensitivity
• early stage diseases – elevated CEA – 5% - 40 %
Prognosis
• Reflect burden of tumor
• Stage of the disease
• Elevated Pre-op level - Predictor of poor survival
& recurrence
17. Monitoring
Recurrent disease
Metastasis
• Hepatic
• Retroperitoneal
• Local
• Pulmonary
• peritoneal
Sensitive
Less sensitive
75 % of the patients with recurrent colo rectal cancers elevate CEA levels
before developing the symptoms
18. Oncofetal antigen
Single chain poly-peptide
Molecular weight – 700 kd
Elevated levels in fetus, pregnancy
decrease sharply after birth
Synthesized by Hepatocytes
Endodermally derived GI tissue
19. Testing
Immuno assay/ RIA
Normal
< 15 ng/ml
Elevated
• HCC
• non-seminiferous testicular cancer
10 to 20% HCC do not have detectable AFP levels
Elevated in non cancer conditions
• Hepatitis
• Inflammatory bowel disease
• cirrhosis
20. Screening
Sensitivity 25% to 75%
Specificity 76% to 94%
Positive predictive value 9% to 50%
Combination of AFP & USG improves the efficacy of the
screening
In combination with β-HCG useful in classification &
monitoring therapy of non-seminiferous testicular carcinomas
22. Monitoring
AFP level drop < 10 ng/ml, after complete resection
If AFP does not drop below 20 ng/ml potoperatively
suspect early recurrence.
AFP levels decline in response to effective
chemotherapy.
Ineffective chemotherapy can be avoided with AFP
monitoring
23. Mucin type glycoprotein expressed on the surface of
the pancreatic cells
Normally present within the biliary tree
Both acute/ chronic biliary tract disease can elevate CA
19-9 levels.
Widely used Serum tumor marker for Ca pancreas
Not a diagnostic marker
Limited use in monitoring the response to therapy
24. Testing
Immunoassay
Normal 37 U/ml
Pancreatic cancer
• Sensitivity 67% to 92%
• Specificity 68% to 92%
Limitations
Patients with –ve Lewis blood group antigen (10% of the population) can not synthesize CA
19-9
Benign biliary tract disease can have up to 400 U/ml (significant number of acute/ chronic
pancreatitis)
Elevated in other cancers Biliary tree - 95%
Stomach – 5%
Colon – 15%
HCC – 7%
Lung – 13%
25. Screening
Not a useful screening modality
Low sensitivity in early stage disease
With increasing levels diagnosis of pancreatic cancer
becomes more accurate
> 1000 U/ml almost diagnostic of pancreatic cancer
Not useful in distinguishing benign from malignant
distal CBD strictures.
26. Prognosis
Levels correlate with the tumor burden
> 95% of unresectable have > 1000 U/ml
Whose levels returned to normal after
curative resection survived longer than those
whose levels fell but never normalized.
27. Monitoring
Serial monitoring
Raised levels after curative resection precede
clinical/ CT evidence of recurrence by 2 to 9
months
Failure of CA 19-9 levels to fall with chemotherapy
reflects poor tumor response.
28. Serine protease – formed in the prostatic
epithelium and secreted in to the prostatic
ducts
Function
• To digest the gel that is formed in seminal fluid after
ejaculation
Under normal circumstances - only small
amount of PSA leak in to the circulation
29. • There are 2 major circulating forms of
PSA:
Free
Complexed:
Complexed to 1-antichymotrypsin or 2-macroglobulin
30. Serum PSA increase
• With enlargement of the gland (BPH)
• Distortion of its architecture
PSA is considered as a tissue specific marker than
prostate cancer specific marker.
Useful marker
• Curative radical prostatectomy
31. Testing
Normal range – increase with age
• 2.5 ng/ml – 40 to 49 yr
• 3.5 ng/ml - 50 to 59 yr
• 4.5 ng/ml - 60 to 69 yr
• 6.5 ng/ml – 70 yr or older
• Rate of PSA increase in a normal 60 yr old – 0.04 ng/ml/yr
Intermediate
• 4 to 10 ng/ ml
Suspicious for malignancy
• . 10 ng/ ml
33. PSA Density
Higher PSA densities are more suggestive
of malignancy than BPH
PSA
Prostatic volume
=
34. PSA Velocity (PSA slope)
Rate of change in the concentration of PSA over time
Individuals with initial levels lower than 4 ng/ml a PSA
slope greater than 0.75 ng/ml/yr is significant
Individuals with initial levels higher than 4 ng/ml a PSA
slope greater than 0.4 ng/ml/yr is significant
35. Screening
Widely used as screening tool for Ca Prostate
Enables early detection & diagnosis
Risk of over diagnosis
• Autopsy studies
Ca prostate found in 55% of men in their 5th decade
Ca prostate found in 64% of men in their 7th decade
Indicating that significant proportion of these cancers are not lethal
Only 1 in 8 screening detected cancers is likely to kill its host if left
untreated.
36. Screening
Annual PSA for screening of prostate cancer:
• in men over 50 years old
• in younger men at high risk: e.g.,
Those with a family history of prostate cancer
• Total PSA: Screening for and in monitoring of
prostate cancer
• Free PSA:
Differentiate levels of PSA that are in the grey zone
Patient with cancer prostate have a lower % of free PSA
.
37. Monitoring
Response to therapy
• After radical prostatectomy
PSA level expected to normalize in 2 to 3 weeks
If PSA remained elevated for 6 months – recurrent disease developed eventually
• Radiotherapy
Takes 3 to 5 months for normalize PSA
Failure to normalize predicts relapse
• A rise in PSA is usually a first sign of
Recurrence
Metastatic progression
38. Carbohydrate epitope on a glycoprotein carcinoma antigen
Present in fetus & its derivatives of coelomic epithelium
• peritoneum
• pleura
• pericardium
• amnion
Normal adults – CA 125 found in the epithelium of
• fallopian tubes
• endometrium
• endocervix
Neithe fetal nor adult ovarian epithelium expresses CA 125
39. Testing
Immunoassay
Normal
• Serum < 35U/ml
• Peritoneal fluid < 200 U/ml
Elevated levels in 80% of ovarian cancer
Ovarian masses with elevated CA 125 has a sensitivity of 75% & specificity of 90% for
malignancy
Also detected in other malignancies
• Gynaecological
Fallopian tube
Endometrium
cervix
• Non gynaecological
Pancreas
Colon
Lung
liver
40. Testing
Benign conditions with elevated CA 125
• endometriosis
• adenomyosis
• uterine fibroids
• PID
• cirrhosis
• Ascitis
CA 125 is adjunt to diagnos Ca Pancreas
rather diagnostic iself
41. Screening – post menopausal women
Poor specificity
Alone is not useful in diagnosing ovarian
cancer
Positive cases are further screened with
transvaginal USG
42. Prognosis
At the time of diagnosis elevated CA 125
have worst prognosis
Percentage of patients with elevated levels
• 50% of Stage I
• 70% of Stage II
• 90% of Stage III
• 98% of Stage IV
43. Monitoring
> 95% of patients levels decrease with partial/ complete
response therapy
Recurrent cases levels elevated 3 months before
clinical/imaging evidence.
Rising level is an indication for second look laparotomy – 95%
times recurrent disease found
Peritoneal fluid level is more sensitive than serum level
44. • Beta HCG is a hormone normally secreted by
trophoblasts in the placenta during pregnancy
• It is a glycoprotein consisting of - and -
subunits
• Detection and follow-up of gestational trophoblastic
diseases (GTDs)
• GTDs include:
Hydatiform mole (vesicular mole)
Choriocarcinoma
45. Non-seminomatous testicular cancers
• β-HCG
> 90% choriocarcinomas
• AFP
90 to 95% yolk sac tumors
20% of teratomas
10% of embryonal carcinomas
46. Diagnosis
Non-seminiferous testicular germ cell cancers
• 50% will have elevated β-HCG
• 60% will have elevated AFP
• 90% will have elevated β-HCG/AFP
Few cases of spuriously elevated HCG/AFP
without testicular cancer
47. Diagnosis
elevation of HCG/AFP without signs of testicular
cancer in younger than 4o yr - Extra testicular
germ cell cancer
Useful in identifying biologically distinct categories
of morphologically similar tumors.
48. Prognosis
Poor
• AFP > 500 ng/ml
• HCG > 1000 ng/ml
Monitoring
Rate of marker decline (half life) calculated weekly after initiation of
chemotherapy, used for early detection of poor response to therapy
Half life
• > 3.5 days for HCG
• > 7 days for AFP
• Increase half life Indicates very aggressive therapy is required.
49. Intermediate size protein filament found in
connective tissue
It make up the cytoskeleton in eukaryotes
along with microtubules and actin
microfilaments
Over expressed in mesodermal tumors
Sarcomas
Studied by immuno histochemistry
50. Marker for breast cancer
HER2 gene is a proto-onco gene located at the long arm of
human chromosome 17(17q21-q22)
Encodes an Epidermal Growth Factor Receptor (EGF-R)
HER2 is a cell membrane surface-bound tyrosine kinase receptor
and is normally involved in the signal transduction pathways
leading to cell growth and differentiation.
51. proto-oncogene converted to oncogene by:
• Mutation (especially point mutation) or
• Altered (over) expression
It is now routinely measured in breast cancer (IHC and
FISH) to determine the type of therapy:
• Breast cancer positive for HER-2/NEU is responsive to
treatment (Herceptin – monoclonal antibody -
Trastuzumab)
52. Tumor marker for Medullary carcinoma thyroid
32-amino acid linear polypeptide hormone
Produced by para-follicular cells (C-cells) of the
thyroid
NMR solution structure Salmon
calcitonin in SDS micelles
Cys-Gly-Asn-Leu-Ser-Thr-Cys-Met-Leu-Gly-Thr-Tyr-Thr-Gln-Asp-Phe-Asn-Lys-Phe-His-Thr-Phe-Pro-Gln-Thr-Ala-Ile-Gly-Val-Gly-Ala-Pro
53. Production regulated by CALC1 gene
regulates blood Ca2+ levels in four ways:
• Inhibits Ca2+ absorption by the intestines
• Inhibits osteoclast activity in bones
• Inhibits phosphate reabsorption by theKidney tubules
• Inhibits tubular reabsorption of Ca2+,leading to increased rates of its loss
in urine
Secretion of calcitonin is stimulated by:
• an increase in serum [Ca2+]
• Gastrin & pentagastrin
55. • The gene is located on chromosome 17 (Plus the genes
of BRCA1 and HER-2/NEU)
• Encodes a protein of 53 kDa protein involved in
protecting cells from unregulated growth
• Encodes a protein that normally result in cell cycle arrest
and induces apoptosis
• mutation: Breast cancer
56. Tumor Tumor marker
Hepatoma (HCC) AFP
Ovarian Cancer CA-125
Inherited ovarian cancer:
BRCA1
Breast Cancer CA15-3
CEA
HER-2/NEU
Estrogen and progesterone
receptors
If inherited: BRCA1, and
BRCA2 (on chromosome 13)
Medullary carcinoma thyroid Calcitonin
CEA
57. Tumor Tumor marker
Ca Pancreas CA 19-9
CEA
Colorectal carcinoma CEA
CA 19-9
pheochromocytoma Catecholamines
(VMA) in urine
Nonseminomatous testicular cancer AFP
-hCG
CEA
Vesicular mole & Choriocarcinoma -hCG
Prostate cancer PSA
58. Tumor marker for carcinoid
{enterochromaffin (Kultschitzsky) cells of the small
intestine}
main metabolite of seratonin.
24-hour urine samples combined with an acidic
additive to maintain pH below 3.
• >25 mg - strong evidence for carcinoid.
59. Neuro endocrine tumor of the adrenal medulla (originating in
chromaffin cells)
Plasma
• Catecholamines
• Chromogranin A
• Metanephrines
Urinary
• Metanephrines
• Vanillyl mandelic acid (VMA)
end-stagemetabolite of the catecholamines
60. Bence Jone protein
• Monoclonal globulin protein – in blood or urine
• Molecular weight 22 – 24 kd
• Diagnostic of Multiple myeloma
• Present in 2/3rd of Multiple myeloma cases.
61. Still at an early discovery stage
Not yet reached the clinic
It has a great potential
• DNA assays for aberrent methylation are easier & more sensitive than
those for point mutations
• Cancer specific DNA methylation patterns can be detected in tumor
derived free DNA in the blood stream & in the tumor cells shed in to the
lumen. - detection & monitoring
• DNA –methylation profiles are more chemically & biologically stable than
RNA or most proteins.
62. Targeted biologic fluid sources of DNA
• Serum/plasma
• Urine – blader cancer
• Sputum
• Saliva
High sensitivity & specificity
Applications
• Early detection
Abnormal DNA methylation patterns in histologically normal cell
• Predict response to therapy
• prognostication
63. No ideal tumor marker is known so far
Therefore, the best approach is:
• good history
• thorough physical examination.
• Use a battery of markers (>1 marker/tumor)
• Use confirmatory investigations:
Appropriate scan, Histopathology