106 Myeloma Flashcards
(166 cards)
Represents the second most common hematologic cancer
Myeloma
- Most patients are diagnosed between 65 and 74 years of age, with a median age at onset of 69 years; only 4% of cases occur before age 45 years.
- Men are affected more frequently than women (ratio: 1.6:1), and individuals of African descent have twice the prevalence of myeloma as those of European descent, regardless of gender.
MGUS is an asymptomatic condition that typically develops years before the diagnosis of myeloma and evolves to a lymphocytic or plasma cell neoplasm at a rate of approximately ______ per year
1% per year
Lifestyle and occupational factors associated with myeloma
- High body mass index
- Exposure to pesticides, organic solvents (benzene, petroleum derivatives, styrene), or chronic radiation
- Thorium dioxide (thorotrast)
- Exposure to acute radiation
- Exposure to fresh wood, wood dust, or working in sawmill factories
- Autoimmune diseases (especially rheumatoid arthritis and pernicious anemia) and chronic viral infections (such as HIV and hepatitis C)
Mutations more frequent in myeloma
- Chromosome 13 deletions
- RAS mutations
- Non–Ig locus–associated MYC translocations
At early stages during the so-called _______________ phase, myeloma cells are totally dependent on marrow microenvironment to survive and on interleukin (IL)-6 and other cytokines.
Intramedullary phase
Most common genomic aberrations in MGUS
Cyclin D dysregulation (60%)
Hyperdiploidy (50%)
Most common genomic aberrations in Myeloma
Cyclin D dysregulation (80%)
Most common genomic aberrations in Plasma Cell leukemia
- Del(13q)/monosomy13 (60%)
- Chr 1g21 amplification (60-80%)
PTEN losses, methylations of p14 promoter, and RB1 inactivations
Mutations that are present at similar rates in MGUS and myeloma.
- Hyperdiploidy
- IGH translocations (t(11;14), t(4;14) and MAF translocations)
These abnormalities are not considered driver events in myeloma.
Postulated as driver myeloma events
- MYC secondary rearrangements
- deletion 13p
- Chromosome 1 abnormalities
- RAS mutations
Traditionally, myeloma patients have been divided into 2 subgroups:
Hyperdiploid: more than 46 but less than 76 chromosomes (34–60% of myeloma)
Nonhyperdiploid: up to 44-45 chromosomes
**Pseudodiploid: 44/45 or 46/47 chromosomes with gains or losses
**Near-tetraploid
Characteristics of hyperdiploid patients
- IgG kappa type with bone involvement
- Gains of odd-numbered chromosomes, including trisomies of chromosomes 15, 9, 5, 19, 3, 11, 7, and 21 (ordered by decreasing frequency)
- Favorable prognosis
Employed to detect five major primary IGH translocations in myeloma, which occur more frequently in nonhyperdiploid patients (85% vs <30%).
Fluorescence in situ hybridization (FISH) analysis
Most frequent translocation (20% of cases)
t(11;14)(q13;q32)
Leading to upregulation of cyclin D1
Subgroup of cyclins with high level expression of cyclin D1, typically responds well to treatment, has an increased frequency of early relapse, but enjoys excellent long-term survival
CD-1 subgroup
Subgroup of cyclins with igh levels of cyclin D3, typically exhibits lymphoplasmacytoid morphology, and has a worse progression-free survival (PFS) and overall survival (OS)
CD-2 subgroup
MAF translocations include:
- t(14;16) : c-MAF overexpression
- t(14;20): deregulates MAFB
- t(8;16): involving MAFA
Rare (5%, 2%, <1% of cases, respectively), but associated with poor prognosis
The prevalence of these three primary IGH rearrangements is similar in MGUS, indicating the need for additional transforming events to precipitate active myeloma.
- t(6;14)
- t(11;14)
- t(14;16)
Copy Number Alterations in Myeloma
Genomic aberrations associated with poor prognosis in myeloma patients
- Deletion of chromosome 13
- Deletion of chromosome 17p13
- Amplification of chromosome 1q21
Deletion of chromosome ______________ affects 50% to 60% of newly diagnosed myeloma, is more frequent in the nonhyperdiploid group (>70%) in comparison to the hyperdiploid group, and often cooccurs with t(4;14) or t(14;16) translocations.
chromosome 13
Deletions of chromosome _______________are rare in newly diagnosed myeloma (5–10%), more common in relapsed and refractory cases (20–40%), and inevitably associated with a negative prognosis, causing early relapse in patients treated with or without autologous stem cell transplantation (SCT).
chromosome 17p involving the TP53 locus
Amplification of________ is detected by FISH in approximately 40% of newly diagnosed myeloma and in 70% of relapsed myeloma, and negatively affects OS
Amplification of 1q21
Translocation described with the TP53 genomic locus, causing simultaneous gain of 1q21 and deletion of 17p.
Jumping translocation of 1q12 (JT1q12)
5 of the 11 genes commonly mutated in myeloma
KRAS, NRAS, FAM46C, DIS3, and TP53