Transcript Assessment of in vivo sensitivity of ALL

ADVANCES IN DIAGNOSIS
AND MANAGEMENT OF
LEUKEMIA IN CHILDREN
Uma Athale MD
Associate Professor, Pediatrics
McMaster University, Hamilton, Canada
December 28th 2015
Objectives




Epidemiology of leukemia in children
Evaluation of a child with suspected leukemia
Recent advances in the diagnosis of acute
leukemia
Overview of therapeutic strategy for ALL and
recent advances in therapy
Objectives



What is the epidemiology of childhood
leukemia in Zambia?
What is the outcome of children with leukemia
in Zambia?
How can we apply the diagnostic and
therapeutic advances in Zambian context?
Case # 1


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BE –a 2.5 yr. old boy presented with H/O fever
for 2-3 weeks
Also complains of pain and has limping
Has been seen by family doctor on and off
Finally referred to a pediatrician
Case # 1
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
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Physical examination reveals a pale child
Irritable
Generalized lymphadenopathy
Liver 5 cm BCM
Spleen 2-3 cm BCM
Case #1

What is your differential diagnosis?

What is your next step?
Epidemiology of Acute
Leukemia



ALL is the most common cancer in children
Peak age 2-5 years
Increased prevalence associated with
industrialization and high-affluent societies
Age-specific Incidence Rate of
Acute leukemia


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
Age adjusted IR per 1000,000
person-years
Both AML and ALL demonstrate
bimodal distribution but a
different pattern
Hispanic whites have the highest
incidence of ALL/L and blacks
the lowest
AML & ALL IR higher in males
T ALL M:F=2.2 whereas BALL/L
1.2
©2012 by American Society of Hematology
Graça M. Dores et al. Blood 2012;119:34-43
Graça M. Dores et al. Blood 2012;119:34-43
Is the epidemiology of childhood ALL
similar in Zambia?



ALL incidence is low < 1/100,00/year) esp. in
children <5 yr. of age
T ALL is more common with peak incidence 514 yr.
ALL and AML occur in equal frequency
Fleming et al. Leukemia, Letter to the Editor, 1999; 13:1292-3
Etiology of ALL
Pathogenesis of ALL




Prenatal origin for some
childhood leukemia
Detection of T-cellreceptor loci in Guthrie
cards
1% newborns are shown to
have TEL/AML1 (ETV6RUNX1) –leukemia
specific putative clone
Monozygotic twin studies
Knudsen Hypothesis
Pathogenesis of ALL


Precise mechanism
unknown
<5% cases are
associated with
 Inherited
predisposing genetic
syndromes
 Down’s
syndrome
 Bloom’s syndrome
 Ataxia-telangiectasia
 Fannin's anemia
 Ionizing
radiation

Many possible
factors
 High
birth weight
 Infection-related

Gene-environment
interaction
Delayedinfection
Population mix
Pui et al. Lancet 2008; 371:1030-43
Biology of ALL


Clonal disease
Genetic mutations in hematopoietic progenitor
cells committed to T or B-cell pathways
 Unlimited
self-renewal
 Stage specific developmental arrest

>70% show chromosomal abnormalities
 Structural
Chromosomal translocations
 TEL-AML1
 Numerical:

, BCR-ABL
Hypodiploidy or hyperdiploidy
Co-operative mutations
Biology of ALL: TEL-AML1



About 25% of
patients with pre-B
ALL
t(12;21)(p13;q22)
Both TEL and AML
genes important for
hemopoiesis
Biology of ALL
Philadelphia chromosome or t(9;22)
>50% T-cell ALL associated with
activating mutations involving
NOTCH1- gene encodes a
transmembrane receptors that
regulate normal T-cell development
Diagnosis of ALL
Sign/Symptoms
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Fatigue, loss of appetite, listlessness
Incidental findings on blood smear
Life threatening infection
Life threatening hemorrhage
Respiratory distress
Symptoms and sign related to INFILTRATION
OF ORGANS
Sign/Symptoms

Bone marrow involvement related
 WBC
 Fever
 Hemoglobin
 Pallor
 Platelet
 Bruises
 Bleeding
 DIC
Sign/Symptoms

Other organ involvements
 Musculoskeletal
pain ( 33% )
 Nocturnal
pain and nonarticular pain
 Compression fracture of vertebrae
 Osteopenia and fracture
 CNS
 Headache,
vomiting, lethargy, nuchal rigidity
 isolated cranial nerves palsy (rare)

Facial nerve palsy
 Spinal
cord compression
Sign/Symptoms

Genitourinary Tract
 Testicular
mass
 Hematuria

Gastrointestinal Tract
 Gingival
hyperplasia
 GI bleeding
Sign/Symptoms
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Respiratory
 Mediatsinal

mass
Cardiac Manifestations
 Pericardial
effusion
Sign/Symptoms

Lymphadenopathy
>
15 mm inguinal lymph nodes
 >10 mm
 > 5 mm for epitrochlear nodes
 Non tender, firm, rubbery and matted
 Hepatosplenomegaly
Testicular involvement
~ 1-2% of boys will have testicular involvement at
the time of initial presentation. Usually older boys
with T cell ALL and HR disease
Testicular ultrasound at relapse
Other unusual presentations
Multiple skeletal manifestations

Osteoporosis

Osetolytic lesions

Moth eaten appearance

Growth arrest lines

Vertebral compression fractures

Periosteal elevation
Bony infiltrate
4 yr old with pallor and bony tenderness in hands
Iranian Journal of Radiology. 2012
March; 9(1): 50-56. , DOI:
10.5812/iranjradiol.6765
Leukemia cutis- a case of
congenital leukemia
Ann Dermatol 2009; 21-66-70
Aleukemic leukemia cutis
Differential diagnoses
Infection
Nodular mastocytosis
Histiocytosis
Leukemia cutis
Acta Derm Venerol 91
Granulocytic sarcoma
Granulocytic sarcoma and gingival
hypertrophy
How to evaluate a patient with
suspected leukemia?

Complete blood count with reticulocytes
 WBC:
May be ↑, ↓or normal
 Platelets: Often ↓
 Hemoglobin: Often ↓


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Differential: Often neutropenia & blasts
10% of patients have “normal” CBC
Usually cannot diagnose type of
leukemia from CBC
Evaluation of a child with
suspected leukemia




Chemistry panel: Electrolytes, BUN,
creatinine, LDH, urate, liver function tests,
serum Ca, PO4, Mg
Viral studies: hepatitis panel, CMV, EBV
serology
?Malaria parasite in endemic area
Peripheral blood flow cytometry with presence
of blasts
Diagnostic Workup: CXR
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R/O mediastinal mass
Present in 5-10% of ALL (often
associated with T-cell subtype)
Mass may cause respiratory
obstruction
Always obtain CXR prior to
sedating patient
Bone Marrow Examination

Aspiration
 Morphology
 Immune
histochemisrty
 Flow cytometry
 Cytogenetics
 Molecular study
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Biopsy
CSF Examination
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First LP after confirmation of diagnosis of
leukemia
Making sure to have platelet count > 50K
Avoiding traumatic LP
Intrathecal chemotherapy at the same time of
first LP
CNS involvement
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
Cranial nerve palsy- chloroma
CSF positivity
Total Cell
count
Cytospin
blasts
CNS I
< 5/hpf
None
CNS II
< 5/hpf
+
CNS II
> 5/hpf
+
ALL Subtypes
Early Thymocyte
Intermediate
Thymocyte
Late Thymocyte
Mature T-Cell
T-Cell ALL
Pluripotent
Stem Cell
Lymphoid
Stem Cell
B-Cell Precursor ALL
Early Pre-B Cell
Pre-B Cell
Immature
B Cell
Burkitt's
ALL
Mature
B cell
Plasma Cell
Diagnosis: Phenotype
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Essential for correct
diagnosis of ALL
Establishment of
definite cell lineage
~ 50% cases will have
myeloid associated
antigen expression
Such aberrant
antigen expressions
have no prognostic
implications
Early Thymocyte
Intermediate
Thymocyte
Late Thymocyte
Mature T-Cell
T-Cell ALL
Pluripotent
Stem Cell
Lymphoid
Stem Cell
B-Cell Precursor ALL
Early Pre-B Cell
Pre-B Cell
Immature
B Cell
Burkitt's
ALL
Mature
B cell
Plasma Cell
Diagnosis: Genotype

Chromosomal analyses- karyotype
 Structural
defects
 Numerical defects

Molecular techniques
 RT-PCR
 FISH

Gene expression profiling- experimental
Outcome
Acute lymphoblastic leukemia : a
prototype of curable cancer
Survival of Children with ALL
Treated on CCG Protocols
100
Years of
Diagnosis
1995-97
1993-95
1989-93
1983-89
1978-83
1975-78
1972-75
% Survival
80
60
40
1970-72
20
1968-70
0
2
4
6
8
Years after Study Entry
10
Survival probability by treatment era for patients enrolled onto Children's
Oncology Group (COG) trials
Five-year
survival
increased
from 83.7%
(SE, 0.4%)
in 1990-1994
to 87.7%
(SE, 0.4%)
in 1995-1999
and to
90.4% (SE,
0.5%) in
2000-2005
Hunger S P et al. JCO 2012;30:1663-1669
©2012 by American Society of Clinical Oncology
ALL: a prototype of curable cancer


Therapeutic advances- anti-leukemic and
supportive care
Biologic advances improving understanding of
ALL pathobiology leading to identification of
novel ALL subtypes
 Development of drug resistance
 Disposition of drugs in the host
 Precise risk stratification


Optimizing risk-directed therapy
(Pui CH, Evans WE. Semin Hematol 2013; 50:185-196)
Risk assessment


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Precise risk assessment important
Therapy optimization
AYA treated on adult-based regimen have
significantly worse prognosis
Superior outcome of peds regimen
 Effective
therapy
 Strict adherence to therapy
Risk factors affecting
prognosis of ALL
Age of the patient
 Initial white cell count
 Presence or absence of CNS disease
 Immunophenotype of leukemic cells
 Genetics of leukemic cells
 Initial response to antileukemic
treatment

Risk assessment: age at ALL
diagnosis
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Strong prognostic factor
SJCRH study (n=847) 5
yr. EFS was
 88%
for pts 1-9 yrs
 73% for 10-15 yrs
 69% for >15 yrs
 44% for infants

Outcome of adults
worsen with increasing
age
Risk assessment: presenting
WBC

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Increasing counts conferring poorer outcome
esp. pre-B ALL
WBC ≥ 50 x 109/L categorized as high risk ALL
In T-ALL WBC count > 100 x 109/L is
associated with increase in CNS relapse
Hyperleucocytosis esp. > 400K is associated
with leucostasis
Risk Assessment:
Immunophenotype



T cell and mature B
cell phenotype are
associated with
higher risk of
relapse
With contemporary
therapy may not be
associated with poor
prognosis
May have agerelated effects
5-year EFS
B-lineage 79 + 1%
T-cell
75 + 4%
p=0.56
DFCI ALL studies (1981-95)
J Clin Oncol 2003; 21:3616
Risk assessment: Genetic
features of lymphoblasts

Favorable features:
Hyperdiploidy (>50 chromosomes)
 TEL-AML1 fusion
 t(1;19)
 Trisomies 4,10 and 17


Unfavorable or high risk features
BCR-ABL
 MLL-AF4 fusion/t(4;11)
 Hypodiploidy (<44 chromosomes)


Age affects prognostic importance of genetic
abnormalities
Genetic features: iAMP21



Intrachromosomal amplification of
chromosome 21
~ 2% of children with ALL with
Associated with
 preB-ALL
 Older
age
 Low white cell count
 Three fold increase in relapse
Blood 2007; 109; 2327-30
Risk factors affecting
prognosis of ALL






Age of the patient
Initial white cell count
Presence or absence of CNS
disease
Immunophenotype of leukemic
cells
Genetics of leukemic cells
Initial response to antileukemic
treatment
ALL: a prototype of curable cancer


Therapeutic advances- anti-leukemic and
supportive care
Biologic advances improving understanding of
ALL pathobiology leading to identification of
novel ALL subtypes
 Development of drug resistance
 Disposition of drugs in the host
 Precise risk stratification


Optimizing risk-directed therapy
(Pui CH, Evans WE. Semin Hematol 2013; 50:185-196)
Earlier studies in childhood ALL
recognized that patients who
required longer treatment to
achieve remission had a lower
likelihood to maintain remission
(Cancer Res 1973;33:3278-3284)
How do we assess CR?

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

Clinical examination – to confirm absence of
organomegaly (liver, spleen, LN) or any leukemia
lesions
CBC to confirm marrow recovery from
myelosuppressive chemotherapy (e.g. platelets ≥
100K and APC ≥ 1.
BM aspiration- morphology, flow cytometry
BM biopsy
LP with CSF examination
Radiological evaluation i.e MR if CNS lesion
Early response to antileukemic
therapy: Funnel Effect
ALL therapy
Therapy
adherenc
e
in vivo response to
therapy
Assessment of in vivo
sensitivity of ALL

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Early blast cell reduction in peripheral blood
(day 8)
Day 15 BM
End of remission-induction bone marrow (BM)
response- complete remission (CR)
However, majority of relapses occur in patients
with M1 or M2 BM on day 15 or even those who
achieve CR at the end of induction
(Campana D. Curr Hematol Malg rep 2012;7:170-177; Borowitz MJ et al. Blood 2008; 111:5477-5485)
Assessment of in vivo sensitivity
of ALL



Early response to therapy in patients with ALL
predicts the risk of relapse
To sharpen the predictive power of early
response it is important to develop better ways
to measure the treatment response
To that effect understanding the leukemic cell
kinetics and treatment response is important
Leukemic burden at various phases of
disease
From: PizzoPA, Poplack DG. Eds. Principles and Practice of Pediatric Oncology, 6th Ed, Lippincot Williams & Wilkins, 2011;548
Leukemic burden at various phases of
disease
Thus, clinical and morphological
remission is compatible with significant
amounts of residual disease
From: Pizzo PA, Poplack DG. Eds. Principles and Practice of Pediatric Oncology, 6 th Ed, Lippincot Williams & Wilkins, 2011;548
Leukemic burden at various phases of
disease
Therapy
abandonment
From: Pizzo PA, Poplack DG. Eds. Principles and Practice of Pediatric Oncology, 6 th Ed, Lippincot Williams & Wilkins, 2011;548
Pitfalls of morphological diagnosis of
“Remission”


Large number of residual blasts despite
attaining “CR”
Misinterpretation of “hematogones” as blasts
Minimal Residual Disease (MRD)
“Lingering” or “sub-morphologic” leukemia
MRD is the disease that is detected by laboratory techniques more sensitive than
morphology
Kinetics of Leukemic cell clearance
MRD estimation by
flow cytometry
MRD level < 10-4
Immunologic remission
was achieved by 2 weeks
in 49% of patients, by 6
weeks in 75% of patients
12% patients required 722 weeks whereas 13%
patients required >22
weeks
Pui CH, Campana D. Leukemia 2000;14:783-785
How low can you go?
Depth of
remission
From: PizzoPA, Poplack DG. Eds. Principles and Practice of Pediatric Oncology, 6th Ed, Lippincot Williams & Wilkins, 2011;548
Minimal Residual Disease (MRD)

Helps to guide therapeutic decisions:
 Early
phases of therapy:
 Identify
patients who responded well to therapy and
hence their therapy can be minimized
 Those patient who require additional or intensive
therapy
 Prior
to stem cell transplant
 Early detection of recurrence or relapse.
MRD Estimation


Number of leukemic blasts present in a
population of nucleated cells following therapy
Major challenges:
 Regenerating
normal immature lymphocytes
 Clonal evolution of leukemia
How to detect MRD?

Choice of technique
 depends
on the aims for MRD estimation
 resource availability
 availability of expertise


Identification of high risk (HR) patients: may
use faster but less sensitive method
To identify “good responders” where therapy
could be minimized requires highly sensitive
method
How to detect MRD?




PCR based method: Allele-specific
oligonucleotide polymerase chain reaction (ASO
PCR) analyses for immunoglobin (Ig) and T cell
receptor (TCR) gene rearrangement
Flow cytometry based method: Multiparametric
flow cytometry (FCM) for detection of aberrant
immunophenotype
PCR for specific translocation like BCR-ABL,
MLL gene rearrangements or TEL/AML1
Deep sequencing
Deep sequencing
methods




High-throughput sequencing method
Universally amplifies antigen-receptor gene
segments and identifies all clonal gene
rearrangements
Capacity to identify all leukemia-specific
sequences
Advantages:
 Detect
clonal evolution
 More precise
 Highly sensitive (<0.01%)
(Faham M et al. Blood 2012; 120:5173-5180)
MRD evaluation in relation to therapy
Remission
induction
Consolidation
Maintenance
Clinical significance of MRD: ALL

Multiple studies from
contemporary therapeutic trial
groups have endorsed the
prognostic correlation of MRD
levels
 during
and end of remission
induction and
 in the early phases of postremission therapy

Independent prognostic marker
End of Induction MRD is the powerful predictor of
Survival: COG study
Patients
with new
diagnoses of
pre B-ALL
(n=1971)
Received 3
drug
dexamethas
one based
(SR) or 4
drug
(prednisone
based) (HR)
induction
therapy
(Borowitz MJ et al. Blood 2008; 111:5477-5485)
Prognostic Significance of Day 8 Peripheral Blood MRD
on EFS:COG study
Satisfactory
peripheral
blood MRD
(n=1920)
70% patients
were MRD
+ve (>0.01%)
5-year EFS for
MRD -ve
patients was
90%
Stepwise
reduction in
EFS at each
(Borowitz MJ et al. Blood 2008; 111:5477-5485)
Risk of relapse by end of induction BM
MRD: DFCI ALL Therapy Protocol 95-01
Undetectable
DFCI study
95-01
(n=284)
10-6 to <10-5
10-5 tp <10-4
10-4 to <10-3
MRD
estimation
for pre B
ALL by PCR
5-yr risk of
relapse was
5% in
children
with no
detectable
MRD (n=
176)
©2007 by American Society of Hematology
10-3 to <0.01
≥ 0.01
Zhou J et al. Blood 2007;110:1607-1611
Risk of relapse by end of induction BM
MRD: DFCI ALL Therapy Protocol 95-001
<1 in 1000
Recursive
partitioning and
clinical
characteristics
identified
optimal cut off
level for MRD to
predict outcome
was 10-3
5-yr risk of
relapse was
12% in children
with low MRD
(n= 246)
compared to
72% in those
with high MRD
(n=38) (p<0.001)
©2007 by American Society of Hematology
>1 in 1000
(Zhou J et al. Blood 2007;110:1607-1611)
MRD estimation in children with de novo ALL



MRD testing has redefined
remission
Strong body of evidence supports
that MRD is an independent
prognostic factor irrespective of
different techniques, age group,
genetic subtypes and
chemotherapy regimens
Major therapy groups now use
MRD based risk stratification for
Relapsed ALL





About 20-25% of children with ALL will suffer
leukemia relapse
The probability of second CR with current salvage
protocols is 70-95%
However cure rates following first relapse are 30-40%
Short duration of first CR, isolated BM relapse and T
cell immunophenotype are poor prognostic features
For high risk relapse ALL the cure rate is ~ 20% with
allogeneic stem cell transplant
Clinical trials have shown that MRD estimation is
clinically informative in children with second CR
(Blood 1991;78:1166-72; Cancer 1998; 82:1387-95; Br J Haematol 2000;108:531-43 and 2002:118:741-7,

J Clin Oncol 2005:23:7942-50)
Infant Leukemia




ALL or AML diagnosed before the age of
1 year
Rare but extremely challenging
Estimated incidence in US:
41 cases per million per yr


~160 cases; 90 with ALL
Aggressive clinical presentation




High WBC
Large hepatosplenomegaly
CNS disease
Leukemia cutis
Infant Leukemia: Role of MLLr
in leukemogenesis




Characterized by balance translocation
involving mixed lineage leukemia (MLL)
gene at locus 11q23
MLL gene rearrangement (MLLr) ocurrs
in ~ 70%-80% of infant ALL and ~50%
in infant AML
Over 79 partner genes- common in ALL
are AF4, ENL, AF9 and AF10 whereas
AF9, AF10 and EML in AML
Acquired in hematopoietic precursers in
utero
Infant leukemia
Infant ALL with MLLr



CD10 negativity + ≥
1 myeloid markers
Poor prognostic
factor (EFS ~35% in
MLLr compared to
60-70% in MLLg)
Chemoresistant
phenotype common
Infant AML with MLLr


Monocytic
differentiation
No prognostic
implication
Infant ALL: Management





Vulnerable host – increased risk of complications and toxicities
Rapidly changing physiology
High induction death rates (15% to 25%)
Long term effects on survivors
Risk based therapy
Brown P. ASH Educational Book 296
Treatment strategy

Induction
Consolidation & CNS prophylaxis
Maintenance
Risk Stratifications
Total length of therapy 2 -3 years

Hamilton – Dana Faber Cancer Institute




Remission Induction Phase

Goal
 To
eradicate 99% leukemic cell burden
 Restore normal hematopoiesis and
 Healthy PS



3- 4 or more drugs in combination including
glucocorticosteroid
CR- change in definition
CR in 96-99% children and 78-93% adults
Consolidation (Intensification)
therapy

Goals
 To
eradicate drug-resistant residual leukemic
cells
 To reduce risk of relapse

Various combinations of drugs
 Asparaginase
 HD
MTX
 ARA-C
 CTX
 Anthracylines
intensification
Continuation (Maintenance)
Therapy

Goal
 To

~ 60% of children with ALL can be cured by 12
months of therapy
 No



prevent or delay relapse
prospective criteria identified
All pts receive 2-2.5 yr therapy
Mercaptopurine and low dose MTX form
mainstay of therapy
Dose adjustment to ANC nadir
Thioguanine vs.
mercaptopurines




6TG more potent than 6MP
Leads to higher intarcellular and CSF
concentration
Produces superior antileukemic respoonse
However associated severe toxicities
 Severe
thrombocytopenia
 Increased rate of death in CR
 Very high rate (10-20%) of hepatic VOD
CNS-directed therapy


CNS relapse- major obstacle in earlier trials
(30-40% relapses)
Risk factors
T
cell ALL
 Hyperleukocytosis
 High risk genetic abnormalities (Ph +ve ALL.
MLL gene rearrangement)
 Presence of leukemic cells in CSF (including
iatrogeneic introduction)
Allogeneic HSCT

Reserved only for certain subtypes of ALL
 Philadelphia
+ve ALL esp in combination with
TKI
 Poor respons eto initial therapy
 Adults with HR disease


Role in Infant ALL unclear
Role in relapsed ALL
Newer therapies
Newer Therapies

Immunotherapy Anti
CD 20, CD 22, anti CD52 antibodies
 CAR-T cells

Novel transplant procedures
 Haplotransplant
Blinatumomab: Anti-CD19 monoclonal antibody
1 - Enables a patients T-Cells to recognize
Malignant B-cells
2 - Has 2 binding sites - CD3 on T-Cell and
CD19 on B-cells
3 - After linking the 2 cells it activates the
T-Cell to exert cytotoxic activity on the
target B-Cell.
CD19
December 2014 approved for use by FDA
for relapsed/refractory (Ph-) B-ALL.
When launched it was the most expensive
cancer drug on the market. ($64,260/mo)
Pui et al. Lancet 2008; 371:1030-43
How do we relate this information to
children in low income countries?
Childhood cancer in LIC
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80% of children affected with cancer live in
low or middle income countries
Overall survival is very poor for these children
even with low risk cancers like ALL
What are the challenges?
Challenges- systems disorder
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Delayed or no diagnosis
Lack of proper therapy
Therapy abandonment
What is the situation in
Zambia?
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Study by Slone and Chunda-Liyoka et al (PLoS
One 9; e89102)
~52% children had cancer diagnosis confirmed
by histopathology
Mortality on therapy was 46%
Abondonment was 46%
How can we change this situation?
Thank you