104 Plasma Cell Neoplasms: General Considerations Flashcards
Characterized by the same primary genetic mutations as in myeloma but do not cause end-organ damage and represent a precursor condition with an average 1%/year risk of progression into myeloma, AL amyloidosis or, more rarely, other lymphoproliferative disorders.
MGUS
The prevalence of FLC-only MGUS is 0.8% in the general population.
It progresses to myeloma in a minority of patients at the rate of 0.3% per year
Nonmodifiable, major risk factors for MGUS
Advanced age, male gender (twofold higher incidence), and African descent
OTHER RISK FACTORS:
Immunocompromised state and occupational exposures to wood and leather manufacturing, asbestos, fertilizers, and pesticides
A family history of MGUS or myeloma in a first-degree relative doubles the risk of developing MGUS.
Nearly 50% of patients with MGUS have PCs with translocations involving the IGH locus on chromosome __________ and most commonly one of these five partner loci: 11q13 (cyclin D1 gene), 4q16 (FGFR-2 and MMSET), 6q21 (CCND3), 16q23 (c-maf), and 20q11 (maf-B).
Chromosome 14q32
The biological events underlying the progression of MGUS to myeloma are undetermined, and there is no single gene mutation or molecular signature predictive of neoplastic transformation.
Compared with MGUS, SM carries a ________ times higher risk of progression to myeloma in the first 5 years after diagnosis.
10
(10% per year)
TRUE OR FALSE
No molecular or chromosomal abnormalities can distinguish between monoclonal gammopathy, SM, or myeloma at the time of diagnosis.
TRUE
No molecular or chromosomal abnormalities can distinguish between monoclonal gammopathy, SM, or myeloma at the time of diagnosis.
Secondary genetic events occur in much higher frequencies in myeloma, such as:
p53 deletions, especially in refractory and extramedullary presentations
N-RAS and K-RAS mutations,
Chromosome 1p deletion
Gain of 1q21
Translocations involving MYC (8q24).
TRUE OR FALSE
There is an increased relative risk of monoclonal gammopathy and myeloma in overweight and obese patients as determined by their body mass index (BMI).
TRUE
There is an increased relative risk of monoclonal gammopathy and myeloma in overweight and obese patients as determined by their body mass index (BMI).
Adiponectin serum concentrations were lower in patients with monoclonal gammopathy who subsequently developed myeloma.
Obese individuals have been shown to have shorter telomeres than nonobese individuals.
Fat tissue is a principal source of _____________, one of the principal growth and antiapoptotic cytokines acting on myeloma cells.
Interleukin (IL)-6
TRUE OR FALSE
Aspirin promotes proliferation and induces apoptosis of myeloma cell lines in vitro through regulation of BCL-2 and BAX and suppression of vascular endothelial growth factor (VEGF).
FALSE
Aspirin inhibits proliferation and induces apoptosis of myeloma cell lines in vitro through regulation of BCL-2 and BAX and suppression of vascular endothelial growth factor (VEGF).
The most important alterations during myeloma development
Decreases of the B-cell receptor (BCR) and the chemokine receptors CXCR5, and CCR7
In contrast, PCs upregulate CXCR4, CD138, and CD38.
PCs also undergo changes to transcription factors highlighted by a decrease in PAX5, CIITA, and EBF.
Represents the most commonly inactivated tumor-suppressor gene in MM
p53
p53 mutations are negatively correlated with survival
30% of patients with PC leukemia present with p53 mutations
The HIV protease inhibitor and ER stressor that has shown activity in overcoming bortezomib resistance in bortezomib-refractory patients in phase I and II clinical studies
Nelfinavir
OTHER PREDICTORS OF DRUG RESISTANCE
Expression of CRBN is therefore necessary for IMiDs to exert their antimyeloma activity, and CRBN downregulation has been reported as an escape mechanism in myeloma patients treated with IMiDs.
CD55 and CD59 levels were significantly higher at the time of progression, suggesting their role in mediating daratumumab resistance
The gold standard for the detection and classification of myeloma.
Fluorescence in situ hybridization (FISH)
Cytogenetic abnormalities, using FISH, are observed in more than 90% of patients with myeloma.
However, FISH cannot provide information about chromosomal abnormalities without the use of large-scale panels of probes.
Hyperdiploid cytogenetic :
Primary genetic mutations are mutually exclusive, and patients with myeloma can be broadly divided into those with hyperdiploidy and those with IgH translocations.
Trisomies of many odd-numbered chromosomes, namely, 3, 5, 7, 9, 15, 19, and 21
Associated with a favorable outcome and considered standard risk cytogenetics.
IgH translocations
Translocations at the IGH loci (14q32), t(4;14), t(14;16), and t(14;20)
Considered high-risk cytogenetics
________drives the overexpression of cyclin D1, is no longer considered a high-risk cytogenetic feature, and is predictive of response to a BCL2 inhibitor.
t(11;14)
Secondary cytogenetic abnormalities and are associated with unfavorable prognosis
Chromosome 17p/17 and 1q
Mayo Stratification of Myeloma and Risk-Adapted Therapy (mSMART)
Standard-risk group
t(6;14) or the t(11;14) translocation
hyperdiploid group
Mayo Stratification of Myeloma and Risk-Adapted Therapy (mSMART)
Intermediate-risk group
t(4;14) translocation and deletions of chromosome 13 or hypodiploidy
deletion of chromosome 13 by metaphase cytogenetics (not by FISH)
Noncytogenetic factor considered intermediate risk: PC labeling index equal or higher than 3%
Mayo Stratification of Myeloma and Risk-Adapted Therapy (mSMART)
High-risk group
t(14;16) or the t(14;20) translocation or deletion 17p13
Noncytogenetic factor considered high risk: high-risk GEP signature
mSMART does not include deletion of chromosome 1p or gain of chromosome 1q in the current stratification.
Both are considered adverse prognostic factors in myeloma, and their occurrence appears in later stages of the disease.
TRUE OR FALSE
Chromosomal aberrations in AL need to be assessed by FISH analysis and conventional metaphase cytogenetics.
FALSE
Chromosomal aberrations in AL need to be assessed by FISH analysis and not by conventional metaphase cytogenetics.
The clonal PC burden in AL is usually small and similar to that seen in patients with MGUS.
Proliferation rate of PCs is very low
Approximately 80% of patients with AL have FISH abnormalities, the most common being
t(11;14)
Detected in 45% to 60% of patients with AL amyloidosis
Other chromosomal abnormalities seen in patients with AL include other IgH translocations, deletion 13/13q–, deletion 17, and gain(1q)
Deletion 17p13 is not seen in this form of amyloidosis.
TRUE OR FALSE
In particular, t(11;14) is associated with same prognosis in amyloidosis and in myeloma, in which it is associated with a good prognosis and is a predictive factor of poor response to bortezomib-based regimens.
FALSE
In particular, t(11;14) is associated with an inferior prognosis in amyloidosis in contrast to myeloma, in which it is associated with a good prognosis and is a predictive factor of poor response to bortezomib-based regimens.
The main cytokines involved in increased bone resorption and suppressed bone formation lead to OLs in patients with myeloma
IL-6, receptor activator of NF-κB ligand (RANKL)/osteoprotegerin (OPG), BAFF, chemokine (C-C motif) ligand 3 (CCL3)–macrophage inflammatory protein (MIP)-1α, and VEGF
Increased bone resorption and suppressed bone formation lead to OLs in patients with myeloma.