Acute Lymphoblastic Leukemia Flashcards
Sentinel somatic mutations that can arise in utero include?
- KMT2A
- ETV6/RUNX1
- ?hyperdiploid ALL
What percentage of infants are born with ETV6/RUNX1 detectable on cord blood?
1%
How many of ETV6/RUNX1 positive infants will develop ALL?
1/100
What is the first step in leukemogenesis?
Developmental arrest
What is the peak incidence of ALL in industrialized countries?
2-4 years old
Peak incidence of AML?
No peak incidence
Known ALL predisposition syndromes? (9)
- Down Syndrome
- Constitutional Robertsonian translocation
- Ataxia telangiectasia (ATM) (T-ALL and NHL)
- Nijmegen breakage syndrome (NBS 1)
- Bloom Syndrome
- Constitutional mismatch repair deficiencies
- Rasopathies (Neurofibromatosis type 1, Noonan Syndrome)
- Klinefelter Syndrome
- Li Fraumeni Syndrome (hypodiploid ALL)
How much more likely are children with Down Syndrome to develop leukemia?
20X
How many children with DS have T-ALL or infant ALL (<1 year old)?
Almost none
In which leukemia predisposition syndrome is there a decreased rate of common sentinel genetic lesions? Which ones are very rare?
- Down syndrome
- KMT2A and BCR-ABL1
Which genetic lesion occurs more frequently in Down Syndrome ALL compared to non-Down Syndrome ALL? What accompanying mutations?
- Over-expression of CRLF2
- JAK and IL7R accompanying
Outcomes for DS with CRLF2r vs non DS with CRLF2r? Overall outcome of DS ALL? What if limit analysis to cases lacking common sentinel genetic lesions?
- Better
- Inferior
- Equivalent
There is an increased risk of ____ in DS-ALL.
Toxic death
Germline predisposition mutations for ALL? Other additional in hypodiploid and B-ALL?
- PAX5 G183S
- TP53 - hypodiploid
- ETV6 - hyperdiploid
- Other for hypodiploid: XRCC1, TP53INP1, FANCA, MLL3, ROS1, SH2B3 (LNK)
Concordance rates between identical twins for leukemia in infants <12 mos?
Close to 100%
Concordance rates for twins for typical childhood B ALL after infancy?
10-15%
Baseline characteristics that influence prognosis outside of NCI risk?
- Presence/absence of extramedullary disease
- Sex
- Race
- Ethnicity
- ALL genotype **(strong influcence)
What is the strongest prognostic factor?
Response to therapy
For what group is NCI risk criteria NOT PROGNOSTIC?
T cell ALL
What percentage of B ALL have standard risk based on NCI criteria? High risk? Infant leukemia? EFS for each?
- ~65% are standard; EFS 90%
- ~34% are high; 5y EFS 75-80% for age >10 (non-infants) or WBC >50
- ~1% are infant; Outcome poor
What percentage of ALL is B?
80-85%
Flow cytometry features of B ALL?
- CD45 positive: distinguishes lymphoid vs. myeloid
- Almost all cases are CD19+, surface CD22+, CD79a+
- Most: CD10+(cALLA+), TdT+ and HLA-DR+
About half of KMT2A-R ALL lack ___ expression.
CD10
Co-expression of _____ is common (_____).
- Myeloid antigens
- CD13/33
- Does not mean it is acute leuk of ambiguous lineage (ALAL) or MPAL!
Early B-lineage ALL are ___ negative. Pre-B ALL is ____.
- cIG-negative
- cIG+, sIG-negative
What percentage of ALL is T ALL?
~15%
Flow cytometry features of T ALL?
- cytoplasmic CD3+
- most sCD3+ and TdT+
- Often express CD2, 4, 7, 8
- CD10 variable
- Most HLA-DR negative
____ is notoriously slower to clear MRD by end of induction. Which value is more important?
- T-cell ALL
- End of consolidation MRD
Flow phenotype for early T precursor (ETP)?
-cCD3+, CD7+, weak CD5,
CD1a-, CD8-
-One or more of on at least 25% of lymphoblasts: CD117+, CD34, HLA-DR, CD13. CD33. CD11b
What is MPAL?
- A subtype of acute leukemia of ambiguous lineage (ALAL)
- Biphenotypic leukemia (most common): Myeloid and lymphoid features on the same cell
- Bilineal leukemia: distinct populations of lymphoid and myeloid blasts (very poor prognosis)
B-Myeloid MPAL has a high incidence of ___-driven leukemia.
ZNf384
Collective data supports initiating therapy for ___ for MPAL.
ALL - this is based on a retrospective review that was not powered to determine a difference, however given burden of acute and late effects of ALL vs. AML therapy, feel reasonable to start with ALL.
HIgh occurence of ____ fusion in MPAL.
BCR/ABL1
Cytogenetic aneuploidies with prognostic significance? incidence and outcome?
- Hyperdiploid - Gain of 4 and 10 (“double trisomy”) +/- 17 (“triple trisomy); incidence ~25%; outcome excellent; less common in patients >15 y o
- Low hypodiploid, haploid, masked hypodiploid (chromosomes doubled): Incidence <3%; poor outcome with modern chemo; ?no benefit to HSCT (2019 papers)
Sentinal translocations in BALL? Molecular, Incidence, Outcome, Comments
Table in your folder
What is Ph-like ALL?
- Defined by an activated kinase gene expression signature similar to that of BCR-ABL1-r (Ph+) ALL
- Driven by cytogenetically-cryptic genetic alterations that activate constitutive kinase signaling
Ph-like ALL is frequently associated with delitions of _____ and other lymphoid transcription factors.
IKZF1
Patients with Ph-like ALL often present with ____ have have high _____ with conventional chemo.
- WBC>/= 50
- EOI MRD
Addition of ____ to chemo may improve event-free and overall survival in Ph-like ALL.
-TKIs
Most common alterations in Ph-like ALL? Drugs for each?
- 50% CRLF2 rearrangements +/- JAK2 or JAK1 point mutations - Ruxolitinib
- 15-20% JAK2 or EPOR rearrangements - Ruxolitinib
- 10-15% ABL class alterations (ABL1, ABL2, CSF1R, PDGFRB rearrangements) - Dasatinib/imatinib
What is the most important prognostic factor for ALL in infants less than 12 months of age? EFS vs in non?
- KMT2A-R
- 37-49% vs. 69-95% in non-KMT2A-R
Which factors are NOT prognostic in T cell?
-Age, WBC, EOI MRD
COG approach to ALL treatment?
See your folder
Techniques to assess MRD should achieve a sensitivity of at least _____.
1/10 000 (0.01%)
CNS disease definitions?
- CNS 1: (0-5 white cells/chamber, 0 blasts, n clinical signs of CNS leukemia)
- CNS 2: (<5 white blood cells/chamber, presence of blasts) or negative by Steinherz-Bleyer algorithm if traumatic tap
- CNS 3: >/=5 white blood cells/chamber, presence of blasts), signs of clinical leukemia, positive by Steinherz/Bleyer algorithm if traumatic tap
Current treatment dose of rads for CNS 3? Includes the ________.
1800cGy
Posterior halves of globes of eyes
Management of CNS 2 disease?
Most groups give extra IT during induction to abrogate poor prognosis
Acute complications of IT chemo?
- Arachnoiditis (headache, N/V, meningismus)
- Seizures (1-2%, particularly with repeat ITs)
- Transient stroke-like symptoms (typically 7-11 days post IT)
- Rare: subacute encephalopathy, myelopathy, weakness/paraplegia linked to IT MTX
Acute complications of cranial irradiation?
5-7 weeks post cXRT: somnolence syndrome
Administration of high dose IV MTX should be given _____ cXRT due to _____ when given after.
- Before
- Increase CNS toxicity
Late complications of CNS-directed therapy?
- Neuroimaging changes: cortical atrophy, necrotizing leukoencephalopathy, subacute leukoencephalopathy, mineralizing leukoencephalopathy (HD MTX may increase risk, uncertain), calcifications (may be most significant finding)
- Impaired intellectual function and school performance (linked to dose and age at time of cXRT, younger is worse)
- Development of secondary brain tumours (10+ years post XRT) - meningioma (15-20 years post XRT) highly curable; but can have HGGs
- Neuroendocrine changes: impaired growth and GH responses; much lower risk if >2400cGy
- Increased risk of obesity
Mechanism of action for inotuzumab, blinatumomab and CAR T cells?
- Inotuzumab: CD22-directed humanized monoclonal antibody conjugated to calicheamicin
- Blinatumomab: Bispecific T-cell receptor engage (BiTE) that redirects CD3+ T cells to CD19+ blasts
- CAR T cells: T cells transduced ex-vivo with chimeric anti-CD19 receptor
Immunotherapy toxicity?
- CRS (associated with higher disease burden)
- Neurotoxicity
Toxicity associated with inotuzumab?
-Sinusoidal obstruction syndrome - elevated risk in post-ino HSCT setting, HIGHER rates in children compared to adults
Prognostic factors following ALL relapse?
- Site of relapse: Bone marrow worse than extramedullary
- Time to relapse: earlier much worse than later
- Age at initial diagnosis: Very poor outcome for teenagers that relapse
- Immunophenotypic and genetic features: BM relapse of T-ALL has very poor outcome
Why is systemic therapy critical for CNS relapse? What is the biggest risk?
Subsequent bone marrow relapse is the biggest risk, so systemic therapy is critical
What percentage of boys will have an isolated testicular relapse?
2%
Standard treatment for testicular relapse? Adverse effects?
- Intensive systemic therapy plus 2400cGy bilateral testicular irradiation - risk of contralateral testicular relapse high without irradiation
- Leads to sterility and need for hormone replacement
Indications for HSCT for relapse?
- ALL with early (<3 years) 1st marrow relapse (may be evolving)
- Increasing use for late marrow relapse with high MRD at end of 1st course of reinduction therapy
- T-ALL BM relapse
- Any 2nd relapse
- Disagreement for early (<18 mos) CNS relapse
What are CAR-T cells?
Genetically engineered receptors that pair an anti-CD19 single chain Fv domain to intracellular T cell signalling domains that result in redirection of T lymphocytes to recognize B ALL cells that express CD19
What determines half life of CAR Ts? Which ones last longer? Role of transplant after infusion?
- Co-stimulatory domains
- 4-1BB last longer than CD28
- Role of transplant after infusion is uncertain
When using CTL-019 (with 4-1BB): CR for relapsed/refractory ALL? 6 month EFS? OS? Durable remissions were seen as far as _______ out.
- CR: 90%
- 6 month EFS: 78% (51-88%)
- OS: 78% (65-95%)
- 24 months
Survivorship issues for leukemia survivors?
- Osteonecrosis
- Cardiac toxicity
- Obesity
- Neurocognitive impairment
- Growth hormone deficiency (if treated with higher dose cranial radiation)
- Insulin resistance
- Muscle weakness
- Peripheral neuropathy
- Liver toxicity (previously seen with 6-TF used instead of 6-MP)
Which chromosome translocation is most likely to be seen in pediatric T-ALL? How common? Prognostic significance?
t(11;14)(p13;q11.2)
in about 7%. Does not appear to have prognostic significance.
The t(9;22)(q34;q11) or Philadelphia chromosome occurs in about ___% of B-cell precursor ALL? T-ALL?
- 4% in B
- <1% in T
What is the t(8;22)(q24;q11) translocation?
fuses c-MYC to the immunoglobulin lambda gene; rare recurrent translocation in Burkitt leukemia and lymphoma
What is the t(1;19)(q23;p13) translocation? What percentage of B?
- TCF3-PBX1 (E2A-PBX1) fusion
- 5% of B-ALL
What is the t(9;11)(q34.q23) translocation?
- MLL-AF9 fusion
- seen commonly in AML, less commonly in B ALL
What is the morphologi finding for Burkitt leukemia?
-Deeply basophilic cytoplasm and cytplasmic vacuoles
What is t(2;8)(p12;q24)?
Translocation that joins c-MYC locus t 8q24 to immunoglobulin heavy or light chain gene. Immunoglobulin kappa gene is located at 2pp12.
Seen in Burkitt Leukemia
What is tocilizumab?
An IL-6 receptor antibody