Oncoproteins

ONCOPROTEINSONCOPROTEINS
( tumour markers)( tumour markers)
andand
EARLY TUMOUREARLY TUMOUR
DIAGNOSISDIAGNOSIS
Guide- Dr VAIDYAGuide- Dr VAIDYA

• INTRODUCTIONINTRODUCTION
• DEFINITIONDEFINITION
• HISTORYHISTORY
• TYPESTYPES
• USESUSES

IntroductionIntroduction
A major challenge in the management of patientsA major challenge in the management of patients
with cancer is the lack of specific tools forwith cancer is the lack of specific tools for
•the early detection,the early detection,
•the accurate prediction of biological behaviorthe accurate prediction of biological behavior
andand
•accurate assessment of prognosisaccurate assessment of prognosis..

Role of a Tumour markerRole of a Tumour marker ??
tumor markers can play a crucial role in detectingtumor markers can play a crucial role in detecting
disease and assessing response to therapy…disease and assessing response to therapy…

Biological basis for tumourBiological basis for tumour
markersmarkers
• Malignant tumours exhibit loss of control overMalignant tumours exhibit loss of control over
proliferation and differentiationproliferation and differentiation
• Many cancers though monoclonal in origin requireMany cancers though monoclonal in origin require multiplemultiple
mutationsmutations to produce malignant cells.to produce malignant cells.
• Multiple mutations == development ofMultiple mutations == development of cell heterogeneitycell heterogeneity
in tumours.in tumours.
• Production ofProduction of multiple tumour markersmultiple tumour markers

Cells isolated from an individual tumour mayCells isolated from an individual tumour may
differ with respect to various factors:differ with respect to various factors:
• growth rategrowth rate
• cell surface receptorscell surface receptors
• immunogenicityimmunogenicity
• their expression of tumour markerstheir expression of tumour markers
• capacity for invasion,capacity for invasion, etc.etc.

How to define a tumour marker?How to define a tumour marker?

DefinitionDefinition
• Any cell product , viz, enzymes, serumAny cell product , viz, enzymes, serum
proteins, metabolites, receptors,proteins, metabolites, receptors,
oncoproteins, oncofoetal proteins , can beoncoproteins, oncofoetal proteins , can be
used as a marker to diagnose the presenceused as a marker to diagnose the presence
of a malignancy, as long as it isof a malignancy, as long as it is
related to any event during tumourrelated to any event during tumour
formation, proliferation, dedifferentiation,formation, proliferation, dedifferentiation,
etcetc

HistoryHistory
• 1846:1846:
discovery ofdiscovery of Bence-Jones proteinsBence-Jones proteins in urine ofcancerin urine ofcancer
patientspatients
• 1965:1965:
The first success in developing a blood test for a common cancerThe first success in developing a blood test for a common cancer
was announced in bywas announced in by Dr. Joseph GoldDr. Joseph Gold. He found a substance in. He found a substance in
the blood of patients with colon cancer that was normally foundthe blood of patients with colon cancer that was normally found
in other tissues and calledin other tissues and called carcinoembryonic antigencarcinoembryonic antigen (CEA).(CEA).

• The first modern tumor marker used toThe first modern tumor marker used to
detect cancer was called human chorionicdetect cancer was called human chorionic
gonadotropin (HCG).gonadotropin (HCG).

• By the end of theBy the end of the 1970's1970's blood tests had beenblood tests had been
developed for several cancers. The new markersdeveloped for several cancers. The new markers
were given numeric labels. There waswere given numeric labels. There was CA19-9CA19-9 forfor
colorectal and pancreatic cancer,colorectal and pancreatic cancer, CA15-3CA15-3 forfor
breast cancer, andbreast cancer, and CA 125CA 125 for ovarian cancer.for ovarian cancer.
• Monoclonal & recombinant DNA technologyMonoclonal & recombinant DNA technology
resulted in the explosive discovery of cancerresulted in the explosive discovery of cancer
markersmarkers

• Early 20Early 20thth
centurycentury : Erlich suggested about: Erlich suggested about
antitumour antibodyantitumour antibody
• 19751975 : Koehler : discovery of Monoclonal: Koehler : discovery of Monoclonal
antibodiesantibodies
• 19871987 : Nakamura and Zola : Advanced: Nakamura and Zola : Advanced
methods of productionmethods of production

Types of Tumour MarkersTypes of Tumour Markers
1.Associated with1.Associated with cell proliferationcell proliferation..
Eg.Eg.
Hormones,Hormones,
enzymes,enzymes,
serum proteinsserum proteins
and their metabolites.and their metabolites.

2.Related to2.Related to metastasesmetastases..
Tumour cells penetrate their adjacentTumour cells penetrate their adjacent
surroundings, invade blood vessels, carried to newsurroundings, invade blood vessels, carried to new
surroundings,surroundings,
- all cell products released during- all cell products released during
these steps- indicate poor risk factors.these steps- indicate poor risk factors.

3.3. Related toRelated to tumour associated eventstumour associated events
Enzymatic activities of various tissue specificEnzymatic activities of various tissue specific
glycosyltranferases are altered in tumour cells.glycosyltranferases are altered in tumour cells.
Eg.Eg.
ca19 ,AFP of primary hepatoma contains anca19 ,AFP of primary hepatoma contains an add fucoseadd fucose
compared to the AFP from benign liver disease.compared to the AFP from benign liver disease.

4.Related to4.Related to malignant transformation.malignant transformation.
Eg. Oncogenes and tumour suppressor genes.Eg. Oncogenes and tumour suppressor genes.

• Biochemical tumorBiochemical tumor markersmarkers are substances developed inare substances developed in
tumor cells and Secreted into body fluids in which theytumor cells and Secreted into body fluids in which they
can be quantified by non-invasive analyses. Because of acan be quantified by non-invasive analyses. Because of a
correlation between marker concentration and activecorrelation between marker concentration and active
tumor mass, they can be used for management oftumor mass, they can be used for management of
malignancy.malignancy.
• oncoproteins :oncoproteins :
proteins encoded by oncogenes which normally maintainproteins encoded by oncogenes which normally maintain
fine balance between cell proliferation and cellfine balance between cell proliferation and cell
differentiation.-- Mutations ---oncoproteins becomedifferentiation.-- Mutations ---oncoproteins become
permanently activated in stimulating cell growth orpermanently activated in stimulating cell growth or
inhibiting cell proliferationinhibiting cell proliferation

• Several studies have documented the feasibilitySeveral studies have documented the feasibility
of using oncoproteins as markers for the presenceof using oncoproteins as markers for the presence
of a tumour.of a tumour.
OncogenesisOncogenesis
tumour initiationtumour initiation •tumour promotiontumour promotion

• MitogenesisMitogenesis
multistep process commences at the cell membranemultistep process commences at the cell membrane
( activation of a growth factor receptor)( activation of a growth factor receptor)
activation of other membrane and cytosolic proteinsactivation of other membrane and cytosolic proteins
signal transduction pathways.signal transduction pathways.

• Mutations in signal transduction proteinsMutations in signal transduction proteins
Progression to neoplasiaProgression to neoplasia

•Different types of mitogenic pathwayDifferent types of mitogenic pathway
elements (oncoproteins) are :elements (oncoproteins) are :

Growth factors:Growth factors:
• Transforming growth factors(TGF) a and b:Transforming growth factors(TGF) a and b:
• tgf b:tgf b: elevated in liver alignancies.elevated in liver alignancies.
invasive bladder cancerinvasive bladder cancer
• Tgf aTgf a : useful in sceening patients for the presence of malignant: useful in sceening patients for the presence of malignant
tumourstumours
Effective predictor of the occurrence of malignancies at anEffective predictor of the occurrence of malignancies at an
early stage.early stage.
Eg. Elevated in people with asbestosis showing prograssionEg. Elevated in people with asbestosis showing prograssion
to lung cato lung ca

Growth factor receptors:Growth factor receptors:
• transmembrane growth factortransmembrane growth factor
receptors encoded by the erbB family of oncogenes arereceptors encoded by the erbB family of oncogenes are
particularly attractive targets for detection in bloodparticularly attractive targets for detection in blood
during cancer development. Extracellular domains ofduring cancer development. Extracellular domains of
these receptors enter circulation and can be detectedthese receptors enter circulation and can be detected
using immunoassays.using immunoassays.
• EGF-ReceptorEGF-Receptor: excellent marker for asbestos induced: excellent marker for asbestos induced
tumours.tumours.

• Platelet derived growth factor(PDGF)Platelet derived growth factor(PDGF) : elevated in 15% of: elevated in 15% of
patients with carcinomas, sarcomas, lymphomas but not inpatients with carcinomas, sarcomas, lymphomas but not in
normal individuals. Higher levels in breast ca indicatenormal individuals. Higher levels in breast ca indicate
shorter survivals.shorter survivals.
• Basic fibroblast growth factor(bFGF)Basic fibroblast growth factor(bFGF) : over 50% of: over 50% of
patients with renal cell ca have elevated levels.patients with renal cell ca have elevated levels.

• Neu/HER-2 receptorNeu/HER-2 receptor :mutations have strong association:mutations have strong association
with breast cancer . Mutated neu oncogene induces overwith breast cancer . Mutated neu oncogene induces over
expression of p185 protein.expression of p185 protein.
• Good correlation between serum ECD level of p185Good correlation between serum ECD level of p185
and tissue level of expression- useful for recurrentand tissue level of expression- useful for recurrent
disease.disease.
• Elevated in 100% of orientals with known risk factorsElevated in 100% of orientals with known risk factors
for hepatocellular ca.for hepatocellular ca.
• Direct correlation between serum levels of p185ECD andDirect correlation between serum levels of p185ECD and
tumour size for premalignant adenomas of the colon.tumour size for premalignant adenomas of the colon.

Cytosolic proteinsCytosolic proteins
• G proteins – signaling proteinsG proteins – signaling proteins
• Mutations in these proteins-Mutations in these proteins-
• conformational changes in proteinsconformational changes in proteins
• These proteins become permanently activated to stimulate cellThese proteins become permanently activated to stimulate cell
division.division.

• The cells undergo malignant transformation that lasts untilThe cells undergo malignant transformation that lasts until
the added mutant protein is metabolised and cleared fromthe added mutant protein is metabolised and cleared from
the cells.the cells.
• Process is well documented forProcess is well documented for ras encoded p21 protein.ras encoded p21 protein.
• Mutant p21 protein abnormal activation ofMutant p21 protein abnormal activation of
alternate unregulated signal transduction pathwaysalternate unregulated signal transduction pathways

• P21 proteins gain access to extracellular environment byP21 proteins gain access to extracellular environment by
unexplained mechanisms can be detected byunexplained mechanisms can be detected by
immunoblottingimmunoblotting
• Elevated serum p21 is a biomarker of early malignantElevated serum p21 is a biomarker of early malignant
disease in patients with a known disposition.disease in patients with a known disposition.
• Known to be increased in patients with pneumoconiosisKnown to be increased in patients with pneumoconiosis
with later progression to cancer.with later progression to cancer.
• Also found in patients with a known exposure to vinylAlso found in patients with a known exposure to vinyl
chloride.chloride.

Nuclear oncoproteins:Nuclear oncoproteins:
important nuclear oncoproteins :important nuclear oncoproteins :
p53 tumour supressor gene proteinp53 tumour supressor gene protein
p62/64 protein encoded by c-mycp62/64 protein encoded by c-myc
oncogeneoncogene
nuclear matrix proteinsnuclear matrix proteins

• P53 proteinP53 protein: represses mitotic process.: represses mitotic process.
• Mutations in p53 causeMutations in p53 cause
conformational changes in the proteinconformational changes in the protein
- loss of normal growth inhibitory function-loss of normal growth inhibitory function-
proteins with increased half lives accumulate in cellsproteins with increased half lives accumulate in cells
leakage into extracellular environment.leakage into extracellular environment.

• Patients with cirrhosis have high levels of p53 in their sera- thus p53Patients with cirrhosis have high levels of p53 in their sera- thus p53
can be an early indicator of hepatocellular ca.can be an early indicator of hepatocellular ca.
• Elevated levels of p53 antibodies are found in patients with ovarianElevated levels of p53 antibodies are found in patients with ovarian
and colon malignancies, lung ca, breast ca..and colon malignancies, lung ca, breast ca..
• appearance of these bodies has been known to precede the occurrenceappearance of these bodies has been known to precede the occurrence
of malignant tumours.of malignant tumours.
• Anti p53 antibodies are elevated in patients with oral premalignantAnti p53 antibodies are elevated in patients with oral premalignant
lesions- marker for early detection of oral ca.lesions- marker for early detection of oral ca.

• Myc oncogene encoded proteinMyc oncogene encoded protein in tumour detection.:in tumour detection.:
function is largely unknown. Elevated in burkitt’s , breastfunction is largely unknown. Elevated in burkitt’s , breast
and colon ca.and colon ca.
• Nuclear matrix proteinsNuclear matrix proteins. These 236-kDa are vital for. These 236-kDa are vital for
correct mitotic spindle formation. Amount of this proteincorrect mitotic spindle formation. Amount of this protein
in malignant transitional epithelial cells is 10 to 20 timesin malignant transitional epithelial cells is 10 to 20 times
more than in normal cells. Specific antibodies formore than in normal cells. Specific antibodies for NMP22NMP22
are now used in commercial ELISA in urine to detectare now used in commercial ELISA in urine to detect
bladder ca. sensitivity is close to 90 % and specificity isbladder ca. sensitivity is close to 90 % and specificity is
over 90 %.over 90 %. Ideal non invasive marker for bladder ca.Ideal non invasive marker for bladder ca.

Biochemical markersBiochemical markers
Tumor MarkersTumor Markers CancersCancers What else?What else? When/How UsedWhen/How Used SampleSample
AFP (Alpha-AFP (Alpha-fetofeto
protein)protein)
Liver, germ cell cancerLiver, germ cell cancer
of ovaries orof ovaries or testestestes
Also elevatedAlso elevated
duringduring pregnancypregnancy
Help diagnose,Help diagnose,
monitormonitor
treatment, andtreatment, and
determinedetermine
recurrencerecurrence
BloodBlood
CA 15-3 (Cancer antigen 15-3)CA 15-3 (Cancer antigen 15-3)BreastBreast and othersand others
including lung,including lung, ovarianovarian
Also elevated inAlso elevated in
benign breastbenign breast
conditions;conditions;
Stage disease,Stage disease,
monitormonitor
determinedetermine
BloodBlood

CA 19-9 (Cancer antigen 19-9)CA 19-9 (Cancer antigen 19-9)Pancreatic, sometimesPancreatic, sometimes
colorectalcolorectal and bile ductsand bile ducts
pancreatitis andpancreatitis and
inflammatory bowelinflammatory bowel
diseasedisease
Stage disease,Stage disease,
monitormonitor
determinedetermine
BloodBlood
CA-125 (Cancer antigen 125)CA-125 (Cancer antigen 125)OvarianOvarian Also elevated withAlso elevated with
endo-metriosis,endo-metriosis,
some other diseasessome other diseases
and benignand benign
conditions;conditions;
monitormonitor
determinedetermine
BloodBlood
CEA (Carcino-CEA (Carcino-
embryonic antigen)embryonic antigen)
Colorectal, lung, breast,Colorectal, lung, breast,
thyroid, pancreatic,thyroid, pancreatic,
liver, cervix, andliver, cervix, and
bladderbladder
Elevated in otherElevated in other
conditions such asconditions such as
hepatitis, COPD,hepatitis, COPD,
colitis, pancreatitis,colitis, pancreatitis,
and in cigaretteand in cigarette
smokerssmokers
MonitorMonitor
treatment andtreatment and
determinedetermine
BloodBlood

Estrogen receptorsEstrogen receptors BreastBreast Increased inIncreased in
hormone-hormone-
dependentdependent
cancercancer
DetermineDetermine
prognosisprognosis
and guideand guide
treatmenttreatment
TissueTissue
hCG (HumanhCG (Human
chorionicchorionic
gonadotropin)gonadotropin)
Testicular andTesticular and
trophoblastictrophoblastic
Elevated inElevated in
pregnancy,pregnancy,
testiculartesticular
failurefailure
monitormonitor
treatment,treatment,
andand
determinedetermine
Blood,Blood,
urineurine
Her-2/neuHer-2/neu BreastBreast Oncogene that isOncogene that is
present inpresent in
multiple copiesmultiple copies
in 20-30% ofin 20-30% of
invasive breastinvasive breast
cancercancer
DetermineDetermine
prognosisprognosis
and guideand guide
treatmenttreatment

TissueTissue

MonoclonalMonoclonal
immunoglobulinsimmunoglobulins
Multiple myeloma andMultiple myeloma and
Waldenstrom’sWaldenstrom’s
macroglobulinemiamacroglobulinemia
Overproduction ofOverproduction of
an immunoglobulin oran immunoglobulin or
antibody, usuallyantibody, usually
detected by proteindetected by protein
electrophoresiselectrophoresis
monitormonitor
determinedetermine
Blood,Blood,
urineurine
ProgesteroneProgesterone
receptorsreceptors
BreastBreast Increased inIncreased in
hormone-dependenthormone-dependent
cancercancer
DetermineDetermine
prognosis andprognosis and
guide treatmentguide treatment
TissueTissue
PSA (ProstatePSA (Prostate
specific antigen),specific antigen),
total and freetotal and free
ProstateProstate Elevated in benignElevated in benign
prostaticprostatic
hypertrophy,hypertrophy,
prostatitis and withprostatitis and with
ageage
Screen for andScreen for and
help diagnose,help diagnose,
monitormonitor
determinedetermine
BloodBlood

B2M (Beta-2B2M (Beta-2
microglobulin)microglobulin)
Multiple myeloma andMultiple myeloma and
lymphomas. Csf valueslymphomas. Csf values
are a good indicator ofare a good indicator of
cns metastasiscns metastasis
Present in manyPresent in many
other conditions,other conditions,
including Crohn’sincluding Crohn’s
disease anddisease and
hepatitis; oftenhepatitis; often
used to determineused to determine
cause of renalcause of renal
failurefailure
DetermineDetermine
prognosisprognosis
BloodBlood
BTA (Bladder tumorBTA (Bladder tumor
antigen)antigen)
BladderBladder Gaining acceptanceGaining acceptance Help diagnose andHelp diagnose and
determinedetermine
UrineUrine
CA 72-4 (CancerCA 72-4 (Cancer
antigen 72-4)antigen 72-4)
OvarianOvarian No evidence that itNo evidence that it
is better than CA-is better than CA-
125 but may be125 but may be
useful whenuseful when
combined with itcombined with it
Help diagnoseHelp diagnose BloodBlood

CalcitoninCalcitonin Thyroid medullaryThyroid medullary
carcinomacarcinoma
pernicious anemiapernicious anemia
and thyroiditisand thyroiditis
monitor treatment,monitor treatment,
and determineand determine
BloodBlood
NSE (Neuron-NSE (Neuron-
specific enolase)specific enolase)
Neuroblastoma, smallNeuroblastoma, small
cell lung cancercell lung cancer
May be better thanMay be better than
CEA for followingCEA for following
this particular kindthis particular kind
of lung cancerof lung cancer
Monitor treatmentMonitor treatment BloodBlood

Tumor MarkersTumor Markers CancersCancers What else?What else?
When/HowWhen/How
UsedUsed
SampleSample
Prostatic acid phosphatase (PAP)Prostatic acid phosphatase (PAP) MetastaticMetastatic
prostate cancer,prostate cancer,
myeloma, lungmyeloma, lung
cancercancer
Not widely usedNot widely used
anymore,anymore,
elevated inelevated in
prostatitis andprostatitis and
otherother
conditionsconditions
S-100S-100 MetastaticMetastatic
melanomamelanoma
Not widely usedNot widely used Help diagnoseHelp diagnose BloodBlood
TA-90TA-90 MetastaticMetastatic
melanomamelanoma
Not widelyNot widely
used, beingused, being
studiedstudied
ThyroglobulinThyroglobulin ThyroidThyroid Used afterUsed after
thyroid isthyroid is
removed toremoved to
evaluateevaluate
treatmenttreatment
DetermineDetermine
BloodBlood

Oncoproteins versus oncofoetal proteinsOncoproteins versus oncofoetal proteins
• Sensitivity of these proteins for tumourSensitivity of these proteins for tumour
detection is high and exceeds that for anydetection is high and exceeds that for any
of the oncofoetal antigens. Specificity ofof the oncofoetal antigens. Specificity of
using growth factors and oncoproteins asusing growth factors and oncoproteins as
tumour markers is also relatively high.tumour markers is also relatively high.
• But absence of a particular marker doesBut absence of a particular marker does
not indicate absence of malignancy.not indicate absence of malignancy.

• one manner of using serum oncproteins to detectone manner of using serum oncproteins to detect
specific tumours at an early stage, is onspecific tumours at an early stage, is on
populations known to be at risk for developingpopulations known to be at risk for developing
specific cancers , either from a history ofspecific cancers , either from a history of
exposure to carcinogens or mutagens or from preexposure to carcinogens or mutagens or from pre
existing medical conditions.existing medical conditions.
• All studies indicate that malignant lesionsAll studies indicate that malignant lesions
undetected by conventional techniques may beundetected by conventional techniques may be
detected by tumour markersdetected by tumour markers

•What makes an ideal tumour markerWhat makes an ideal tumour marker ??

Properties of an ideal tumor markerProperties of an ideal tumor marker
• High clinical sensitivityHigh clinical sensitivity
• High clinical specificityHigh clinical specificity
• Tumour marker levels should be proportional toTumour marker levels should be proportional to
tumour volumetumour volume

• Should have short half life to rapidlyShould have short half life to rapidly
mirror treatment schedulesmirror treatment schedules
• Should reflect tumor heterogeneityShould reflect tumor heterogeneity
( secreting multiple( secreting multiple markersmarkers))
• Should have low levels in healthy populationShould have low levels in healthy population

• Should be discriminatory enough to identifyShould be discriminatory enough to identify
tumor and metastasis from healthy statestumor and metastasis from healthy states
• Should provide adequate lead time forShould provide adequate lead time for earlyearly
diagnosisdiagnosis andand earlyearly treatmenttreatment

The first clues to a hiddenThe first clues to a hidden
malignancymalignancy ??.......??.......
(If interpreted properly)(If interpreted properly)

•Applications of tumour markersApplications of tumour markers ……

• ScreeningScreening
• Screening of asymptomatic individuals, mostly in high risk groups:Screening of asymptomatic individuals, mostly in high risk groups:
• Eg. AFP in liver cancer in ChinaEg. AFP in liver cancer in China
• Urinary vanilyllmandelic and homovanillic acid forUrinary vanilyllmandelic and homovanillic acid for
neuroblastomas in Japanese childrenneuroblastomas in Japanese children
• Prostate specific antigen (PSA) for prostate cancerProstate specific antigen (PSA) for prostate cancer
• The presence of a high level of CA 125 will strongly suggest ovarian cancer,The presence of a high level of CA 125 will strongly suggest ovarian cancer,
even if the surgeon sees only a mass of tumor, and cannot locate the ovarieseven if the surgeon sees only a mass of tumor, and cannot locate the ovaries
inside the mass.inside the mass.

Differential Diagnosis,Differential Diagnosis,
Classification, Staging & GradingClassification, Staging & Grading
• Identifying origin of metastasis eg PSA in distant organsIdentifying origin of metastasis eg PSA in distant organs
• Useful in analysis of anaplastic tumours. Eg:Useful in analysis of anaplastic tumours. Eg:
for epithelial tumours, Pankeratin, CEA, NSE, EMA, B27.3 etc can befor epithelial tumours, Pankeratin, CEA, NSE, EMA, B27.3 etc can be
usedused
• For mesenchymal tumours, vimentin, desmin etc can be of useFor mesenchymal tumours, vimentin, desmin etc can be of use
• Classification of non-hodgkins lymphoma & distinguishingClassification of non-hodgkins lymphoma & distinguishing
it from undifferentiated cancer of non-hematopoieticit from undifferentiated cancer of non-hematopoietic
originorigin

PrognosisPrognosis
• Prognosis is the probability of cure in cancer patient.Prognosis is the probability of cure in cancer patient.
• (Well differentiated tumour has better outcome than the anaplastic(Well differentiated tumour has better outcome than the anaplastic
ones)ones)
• Estrogen receptor+ve breast tumors have good prognosis -Estrogen receptor+ve breast tumors have good prognosis - ??
• C-erb-2-gene(HER-2/nen) is prognostic for ovarian &C-erb-2-gene(HER-2/nen) is prognostic for ovarian &
breast cancerbreast cancer

Monitoring &Monitoring &
RecurrenceRecurrence
• Most important application of cancerMost important application of cancer markersmarkers
• If the marker level in the blood goes down, that is almost always aIf the marker level in the blood goes down, that is almost always a
sign that the treatment is effective. On the other hand, if it goes up,sign that the treatment is effective. On the other hand, if it goes up,
then the treatment probably should be changed.then the treatment probably should be changed.
• Provides therapeutic alternatives in specific unsuccessfulProvides therapeutic alternatives in specific unsuccessful
treatment modalitiestreatment modalities

Monitoring Cancers with MultipleMonitoring Cancers with Multiple
MarkersMarkers
• In some tumors (eg pancreatic) detectionIn some tumors (eg pancreatic) detection
of sialyl Lewis ag,(CA19-9), CA50 & CEAof sialyl Lewis ag,(CA19-9), CA50 & CEA
may all be elevatedmay all be elevated
• In germ cell tumors, hCG and AFPIn germ cell tumors, hCG and AFP
measurement confirmsmeasurement confirms diagnosisdiagnosis

Monitoring &Monitoring &
RecurrenceRecurrence
• PredictsPredicts earlyearly recurrence of metastasis 6-18 monthsrecurrence of metastasis 6-18 months
earlier than other methods.earlier than other methods.
• Many women with breast cancer, for example, have yearlyMany women with breast cancer, for example, have yearly
blood tests for levels of CA-15-3.blood tests for levels of CA-15-3.
This can detect cancer recurrence before the patient hasThis can detect cancer recurrence before the patient has
symptomssymptoms
• Can avoid unnecessary surgery or chemotherapy inCan avoid unnecessary surgery or chemotherapy in
advanced cancersadvanced cancers

•Tumour markers in malignant diseasesTumour markers in malignant diseases ……

DiseaseDisease MarkerMarker
MarkerMarker
still atstill at
experimenexperimen
tal stagetal stageScreeningScreening
DetectionDetection
andand
diagnosisdiagnosis
StagingStaging
andand
prognosisprognosis Follow upFollow up
ColonColon
cancercancer
CarcinoemCarcinoem
bryonicbryonic
antigenantigen
(X)(X) XX
BreastBreast
cancercancer
OestrogenOestrogen
receptorreceptor
XX
CA15.3CA15.3 XX XX XX
CA27.29CA27.29 XX
Her-2/neuHer-2/neu XX XX

DiseaseDisease MarkerMarker MarkerMarker
still atstill at
experimeexperime
ntal stagental stageScreeningScreening DetectionDetection
andand
diagnosisdiagnosis
StagingStaging
andand
prognosisprognosis
Follow upFollow up
ProstateProstate
cancercancer
Prostate specificProstate specific
antigenantigen
(X)(X) XX
OvarianOvarian
cancercancer
CA125CA125 XX XX
CA19.9 (CA74.2)CA19.9 (CA74.2) XX
ThyroidThyroid
cancercancer
ThyroglobulinThyroglobulin XX XX
CalcitoninCalcitonin XX XX
TesticularTesticular
cancercancer
Human chorionicHuman chorionic
gonadotrophingonadotrophin
XX XX
FetoproteinFetoprotein XX XX

MarkerMarker
still atstill at
experimeexperime
ntal stagental stageScreeningScreening
Detection andDetection and
diagnosisdiagnosis
StagingStaging
andand
Sarcoma:Sarcoma:
SynovialSynovial
sarcomasarcoma
t(X;18)t(X;18) XX XX
Ewing'sEwing's
sarcomasarcoma
t(11;22)t(11;22) XX
AlveolarAlveolar
rhabdomyosrhabdomyos
arcomaarcoma
t(2;13)t(2;13) XX
GranolyticGranolytic
sarcomasarcoma
t((9;11)t((9;11) XX

MarkerMarker
still atstill at
experimeexperime
diagnosisdiagnosis
StagingStaging
andand
    Myxoid Myxoid
liposarcomaliposarcoma
t(12;16)t(12;16) XX
    Round cell Round cell
liposarcomaliposarcoma
t(12;16)t(12;16) XX
    Congenital Congenital
fibrosarcomafibrosarcoma
t(2;15)t(2;15) XX
    Clear cell Clear cell
sarcomasarcoma
t(12;22)t(12;22) XX

MarkerMarker
still atstill at
experimeexperime
diagnosisdiagnosis
StagingStaging
andand
DermatofiDermatofi
brosarcoma brosarcoma
protuberansprotuberans
t(17;22)t(17;22) XX
MelanomaMelanoma TyrosinaseTyrosinase XX
Adrenal Adrenal
carcinomacarcinoma
SteroidsSteroids XX
CatecholaCatechola
minesmines
XX

MarkerMarker
still atstill at
experimeexperime
diagnosisdiagnosis
StagingStaging
andand
LymphomaLymphoma t(8;14)t(8;14) XX XX XX
t(11;14)t(11;14) XX XX XX
t(2;5)t(2;5) XX XX XX
t(3;14)t(3;14) XX XX XX
sCD25sCD25 XX
sCD44sCD44 XX
LeukaemiaLeukaemia Numerous Numerous
cytogenetic cytogenetic
alterationsalterations
XX XX

•Ways to detect tumour markersWays to detect tumour markers ……

• Immunohistochemistry-Immunohistochemistry-
Use- to detect antigenic changesUse- to detect antigenic changes
associated with malignant transformationassociated with malignant transformation

Types of changesTypes of changes
• New expression of tumour specific antigensNew expression of tumour specific antigens
include oncoproteins.include oncoproteins.
• Microanatomic changes in cellular distribution ofMicroanatomic changes in cellular distribution of
antigens.- cell surface antigens such as CEA,antigens.- cell surface antigens such as CEA,
B27.3, EMA have an apical or luminal distributionB27.3, EMA have an apical or luminal distribution
in benign cells . in malignant cells, there isin benign cells . in malignant cells, there is
distribution in the over all cell.distribution in the over all cell.

• Changes in the level of antigen expression –Changes in the level of antigen expression –
increased expression eg CEA, OC125increased expression eg CEA, OC125
Decreased expression eg GCDFP-15, thyroglobulinDecreased expression eg GCDFP-15, thyroglobulin
and calcitoninand calcitonin
• Alteration in biochemical nature of antigens. Eg.Alteration in biochemical nature of antigens. Eg.
Expression ofLewis blood group ag by exfoliatedExpression ofLewis blood group ag by exfoliated
urothelial cells significantly improves theurothelial cells significantly improves the
detection of urothelial tumoursdetection of urothelial tumours

• There is positive correlation betweenThere is positive correlation between
increased proliferation and p53 geneincreased proliferation and p53 gene
abnormalities.abnormalities.
• There is substantial evidence thatThere is substantial evidence that
increased proliferation as assessed byincreased proliferation as assessed by
immunohistochemical methods using Ki-67immunohistochemical methods using Ki-67
or PNCA allows identification of patientsor PNCA allows identification of patients
whose tumours are more likely to progresswhose tumours are more likely to progress

• Immunohistochemical assays can be used onImmunohistochemical assays can be used on
extremelyextremely small tissue specimenssmall tissue specimens, including, including
cytologic preparations of cell, and on corecytologic preparations of cell, and on core
needle biopsy specimensneedle biopsy specimens
• Added advantage is that theAdded advantage is that the entireentire
populationpopulation of cells within a representativeof cells within a representative
portion of the tumour can be assessedportion of the tumour can be assessed
unlike the clonogenic assay, in whichunlike the clonogenic assay, in which
specific clones of cells may be selectedspecific clones of cells may be selected

• Immunoassays :Immunoassays :
• Effect of assay designsEffect of assay designs::
• Impact of a test design affects the sensitivity,Impact of a test design affects the sensitivity,
specificity and level of hook effect occurence.specificity and level of hook effect occurence.
• Diferrent types:Diferrent types:
• Competitive binding:Competitive binding: first RIAfirst RIA was developed on thewas developed on the
competitivecompetitive
binding format.binding format.
• Sandwich format:Sandwich format: ELISAELISA using the sandwich format hasusing the sandwich format has
become thebecome the

• Monoclonal versus polyclonal abMonoclonal versus polyclonal ab
Monoclonal antibody defined tumourMonoclonal antibody defined tumour
markers are produced by the Hybridomamarkers are produced by the Hybridoma
technique-technique-

focus on small area , an epitope or antigenic determinant-focus on small area , an epitope or antigenic determinant-
produced by injecting a mouse with an enriched fractionproduced by injecting a mouse with an enriched fraction
of the tumour cell membrane/ whole cell-of the tumour cell membrane/ whole cell-
hybridomas are selected through screening-hybridomas are selected through screening-
unlimited and constant supply of ab – tumour assounlimited and constant supply of ab – tumour asso
epitopes.epitopes.

Recommendations for ordering tumour marker tests:Recommendations for ordering tumour marker tests:
• Never rely on the results of a single testNever rely on the results of a single test
• When ordering serial testing be certain to orderWhen ordering serial testing be certain to order
every test from the same laboratory using theevery test from the same laboratory using the
same kitsame kit
• Be certain that the tumour marker selected forBe certain that the tumour marker selected for
monitoring recurrence was elevated prior to themonitoring recurrence was elevated prior to the
surgerysurgery
• Consider half life of tumour marker whenConsider half life of tumour marker when
interpreting the resultinterpreting the result

• Consider how the tumour marker is metabolizedConsider how the tumour marker is metabolized
or removed from the circulationor removed from the circulation
• Consider ordering multiple markers to improveConsider ordering multiple markers to improve
sensitivity and specificitysensitivity and specificity
• Order the non specific markers for cost savingOrder the non specific markers for cost saving
and high sensitivityand high sensitivity
• Be aware of the possibility of hook effect andBe aware of the possibility of hook effect and
lastly,lastly,
• Be aware of possibility of ectopic markersBe aware of possibility of ectopic markers

The future :The future :
may be possible to :may be possible to :
identify the totipotent cells that are carcinogenicidentify the totipotent cells that are carcinogenic
or apt to become cancerousor apt to become cancerous
And to have means to destroy these cellsAnd to have means to destroy these cells
beforehandbeforehand

ReferencesReferences
• Todd’s : Clinical DiagnosisTodd’s : Clinical Diagnosis andand ManagementManagement byby
Laboratory Methods ,Laboratory Methods , Twentieth editionTwentieth edition
• Anderson’s Pathology,Anderson’s Pathology, Tenth editionTenth edition
• Tumour markers and tumour associated antigensTumour markers and tumour associated antigens
• Inter NetInter Net

Oncoproteins

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Oncoproteins

Similar to Oncoproteins (20)

More from Appy Akshay Agarwal

More from Appy Akshay Agarwal (20)

Recently uploaded

Recently uploaded (20)

Oncoproteins