6.3. Studies Focusing on the Study of WES in Myeloma Patients by the NGS
Whole-exome sequencing (WES) by next-generation sequencing (NGS) has been utilized in several ways to study MM: identification of somatic mutations, characterization of clonal architecture, prognostic biomarker discovery or drug target discovery.
Overall, WES by NGS is a powerful tool for studying MM and has the potential to help researchers better understand the disease and develop more effective treatments.
15.38% of the studies selected in our review are interested in the study of the exome “Whole Exome Sequencing” WES data. Those studies are reported in the table below and an analysis and discussion of the results of those studies is quoted directly after the table.
Table 2.
Studies focusing on the study of Whole Exome Sequencing.
Table 2.
Studies focusing on the study of Whole Exome Sequencing.
|
Study |
Year of the study |
Country |
Number of patients used in the study |
Type of patients |
Type of samples used |
1 |
[30] |
2022 |
Erbil Iraq |
- |
- |
PB |
2 |
[31] |
2021 |
New delhi India |
62 |
- |
- |
3 |
[32] |
2021 |
AIIMS, New Delhi |
71 |
NDMM |
PCs |
4 |
[33] |
2021 |
Helsinki, Finland |
8 |
- |
BM |
5 |
[34] |
2021 |
New York, NY |
1154 |
- |
- |
6 |
[35] |
2020 |
Galway, Ireland |
291 |
RRMM |
BM |
7 |
[36] |
2020 |
Tampa, FL |
196 |
- |
- |
8 |
[37] |
2019 |
Turin, Italy |
42 |
RRMM |
- |
9 |
[38] |
2019 |
Milano, Italy |
40 |
RRMM |
- |
10 |
[39] |
2018 |
Arkansas USA |
1141 |
- |
|
11 |
[40] |
2018 |
Wurzburg Germany |
1 |
- |
- |
12 |
[41] |
2018 |
Boston, MA |
629, 1144, 205 |
MM, NDMM, NDMM |
PB |
13 |
[42] |
2017 |
Boston MA |
186 |
- |
- |
14 |
[43] |
2017 |
Adelaide Australia |
10 |
- |
- |
15 |
[44] |
2017 |
New York USA |
19 |
- |
- |
16 |
[45] |
2017 |
Boston, MA |
151 |
MM, SMM, MGUS |
PB |
17 |
[46] |
2017 |
Liège, Belgium |
10 |
- |
BM |
18 |
[47] |
2016 |
Cambridge UK |
14 |
- |
- |
19 |
[48] |
2016 |
Southampton UK |
25 |
- |
- |
20 |
[49] |
2016 |
Boston, MA |
63 |
NDMM, RRMM, SMM, MGUS |
PB |
21 |
[50] |
2016 |
- |
1000 |
NDMM |
- |
22 |
[51] |
2016 |
Little Rock, AR |
2161 |
- |
- |
23 |
[52] |
2016 |
Little Rock, AR |
33 |
- |
- |
24 |
[53] |
2015 |
Boston, MA, USA |
29 |
- |
- |
25 |
[54] |
2015 |
Little Rock, AR |
- |
- |
BM |
26 |
[55] |
2014 |
Cambridge UK |
23 |
- |
- |
27 |
[56] |
2012 |
London, United Kingdom |
- |
- |
BM |
28 |
[57] |
2011 |
Boston, MA, USA |
- |
- |
- |
Some of these studies aim to investigate the genetic landscape of multiple myeloma, like the study carried out by Kakoo et al. which included 22 MM patients from Iranian population, the WES analysis revealed 6,959 somatic mutations across all patients and the most commonly mutated genes in MM patients were TP53, KRAS, NRAS, DIS3, and FAM46C.
This study recognized potential novel driver genes in MM, including ARID1A, RYR2, and ARID2 and also highlighted the potential clinical implications of the identified mutations, such as the association between TP53 mutations and worse overall survival in MM patients.
The authors also found that the mutational landscape of MM patients in the Iranian population was distinct from other populations, with some specific mutations being more prevalent in Iranian MM patients [
58]. The study conducted by Munshi et al. identified recurrent mutations commonly seen in multiple myeloma cells. These recurring mutations included: the TP53, KRAS and NRAS genes which were found in up to 20% of multiple myeloma cases studied in this study, the DIS3 gene: which is involved in the degradation of messenger RNA and which has been identified in up to 13% of cases of multiple myeloma, the FAM46C which is involved in the regulation of protein synthesis and which has been mutated in up to 15% of cases, finally, the IRF4 gene, which plays a role in regulating immune responses, has been found to be mutated in approximately 20% of cases [
57]. In the study conducted by Bolli et al., these genes were investigated as recurring mutations. KRAS and NRAS mutations were detected in 36% of patients, TP53 mutations were found in 28% of patients, which is a common mutation observed in various types of cancer, including MM. DIS3 mutations were identified in 20% of patients, FAM46C mutations were observed in 16% of patients, and TRAF3 mutations were found in 12% of patients. TRAF3 is a gene that has also been associated with the development of MM [
47].
KRAS, NRAS, TP53, DIS3 and FAM46C are also the most frequently mutated genes in the study carried by Manier et al., this study which involved 45 patients with MM and sequenced their cfDNA samples using both WES and targeted deep sequencing panels. The research detected a total of 4714 somatic mutations in all patients, with an average of 104 mutations per patient [
49]. In the study conducted by Miller et al., specific gene mutations were linked to the duration of progression-free survival (PFS) in multiple myeloma (MM) patients. KRAS and NRAS mutations were associated with longer PFS, while TP53 mutations were associated with shorter PFS. This particular study focused on analyzing exome sequencing data from 765 MM patients with the aim of investigating the relationship between the burden of somatic mutations, neoantigen load, and progression-free survival (PFS) in MM patients [
50].
The study by Walker, Samur, et al. and that performed by Munshi et al. joins the set of previous studies in identifying TP53, KRAS and NRAS as genes frequently mutated in affected patients and which are associated with a poor prognosis and higher-risk molecular subtypes. The DIS3, FAM46C and CYLD genes also recurrently mutated and which are involved in the pathogenesis of MM [
51], [
59].
The study conducted by Zielinska et al. study developed a high-throughput pipeline for NGS analysis of multiple myeloma samples. The study found that the NextSeq 500 platform performed well for identifying known gene variants in multiple myeloma samples. The high-throughput pipeline developed in the study was also found to identify various gene variants in multiple myeloma samples, including mutations in the TP53, KRAS, NRAS, and BRAF genes [
54].
Another study conducted by Bolli et al. sequenced the exomes of tumor cells from 50 MM patients and matched germline DNA from 44 of them. Additionally, they sequenced the IGH locus and performed copy number analysis on the tumor cells.
The study identified a range of mutations and copy number changes in the MM tumor cells, including mutations in genes such as KRAS, NRAS, TP53, and DIS3, as well as copy number gains or losses in chromosomes 1, 6, 8, 9, 11, 12, 13, 15, 16, 17, and 19. The study also detected IGH translocations in 35 out of the 50 MM patients.
The authors also compared their NGS results with those obtained using traditional techniques, for example fluorescence in situ hybridization (FISH) and Sanger sequencing. They found that NGS provided a more comprehensive analysis of genomic abnormalities and enabled the detection of mutations that would have been missed by other methods.
Overall, the study demonstrates the potential of NGS for identifying clinically relevant gene variants in MM and suggests that this approach could be used to guide personalized treatment strategies for MM patients [
55].
So, these studies performed on myeloma patients highlight the importance of the KRAS, NRAS, BRAF, TP53, DIS3 and FAM46C as regularly mutated genes in the pathology of MM and suggest their potential as therapeutic targets or prognostic biomarkers, and in studies investigating smoldering multiple myeloma SMM, mutations in the TP53, BRAF, DIS3, and ATM genes, among others. provide high-risk abnormalities in these patients and can help identify patients who might benefit from early intervention as mentioned in the study by Bustoros et al. for example [
42].
6.4. Studies Involving MRD Assessment by NGS
The World Health Organization (WHO) defines minimal residual disease (MRD) as “the presence of residual disease at levels below the threshold of detection by conventional morphological and cytogenetic techniques” [
60].
MRD testing involve sensitive methods such as flow cytometry, polymerase chain reaction (PCR), or next-generation sequencing (NGS). The detection of MRD is important because it can help to predict a patient’s risk of relapse and guide treatment decisions.
For the assessment of MRD some from our selection studies used the LymphoTrack® IGH panel which is a molecular diagnostic tool utilizes next-generation sequencing (NGS) technology to detect and quantify clonal immunoglobulin heavy chain (IGH) gene rearrangements in the patient’s blood or bone marrow.
The LymphoTrack® IGH panel works in the context of MRD assessment as following:
A sample of the patient’s blood or bone marrow is collected.
DNA is extracted from the sample and sequenced using NGS technology to identify clonal IGH gene rearrangements.
And MRD detection and monitoring how the sequences obtained are compared to those from the patient’s baseline sample to identify any remaining cancer cells that may indicate minimal residual disease (MRD). The level of MRD is then quantified to monitor treatment response and disease progression over time.
There are some studies aimed to compare next-generation sequencing (NGS) and next-generation flow cytometry (NGF) for detecting minimal residual disease (MRD) in multiple myeloma (MM) patients like the one made by Medina et al., (2020) this found that NGS and NGF had similar levels of sensitivity for detecting MRD in MM patients, with NGS detecting MRD in 92% of cases and NGF detecting MRD in 89% of cases. However, NGS was able to detect MRD at lower levels than NGF, with a limit of detection of 0.01% for NGS compared to 0.1% for NGF.
Moreover, the study suggests that both NGS and NGF are effective methods for detecting MRD in MM patients, but NGS may have some advantages in terms of its ability to detect MRD at lower levels. Nevertheless, additional research is required to obtain a more comprehensive understanding which method is more clinically useful in guiding treatment decisions for MM patients [
61].
Another study made by Ha et al. (2022) found that Ig gene clonality analysis using NGS was a highly sensitive and specific method for MRD detection in MM patients. In addition, the study found that MRD negativity by Ig gene clonality analysis using NGS was associated with improved progression-free survival (PFS) and overall survival (OS).
The study also found that Ig gene clonality analysis using NGS was able to detect MRD in a higher percentage of patients than standard flow cytometry-based methods, and that Ig gene clonality analysis was particularly useful in patients with low levels of MRD [
62].
Evaluation of the utility of the NGS-based assay for the detection of MRD was also performed by Ho et al. (2018), where he revealed through his study that the NGS-based test had a high success rate for the clonal characterization of plasma cell neoplasms, with a success rate of 95.7% in the MM cohort. The test was also able to detect MRD in a high percentage of patients, with a sensitivity of 89.5% for detecting MRD in the MM cohort.
The study also found a high degree of concordance between the NGS-based assay and flow cytometry for MRD detection, with a kappa coefficient of 0.68 indicating substantial agreement between the two methods.
Global, the findings of the study indicate that the NGS-based assay may be a useful tool for identifying MRD in plasma cell neoplasms and that it has a high success rate for clonal characterization. The study also suggests that the NGS-based assay has a high degree of concordance with flow cytometry for MRD detection, indicating that it may be a reliable alternative to flow cytometry-based methods for MRD detection [
63].
Similarly, the study realized by M. Kim et al. (2019) on Korean multiple myeloma (MM) patients found that NGS-based analysis of IGH and IGK rearrangements and somatic hypermutation (SHM) status was able to detect clonality in a large proportion of individuals at high-risk MM, with a success rate of 91.5%. The study also found that SHM analysis was able to identify clonality in some patients where rearrangement analysis was not successful, suggesting that SHM analysis may be a useful complementary approach for clonality detection in MM.
In addition, the study found that the clonality status determined by NGS was highly concordant with that determined by conventional methods such as PCR and flow cytometry, indicating that NGS may be a reliable alternative to these methods for clonality detection in MM.
Overall, the study suggests that NGS-based analysis of IGH and IGK rearrangements and SHM status may be a useful tool to identify clonality in MM patients at a high risk, and that it has a high success rate and concordance with conventional methods for clonality detection [
64].
In the same direction of all these studies Rustad and Boyle (2020) study found that NGS was able to detect MRD in a high proportion of patients, with a sensitivity of 95.2% and a specificity of 100% for MRD detection in bone marrow samples. The study also found a high degree of concordance between NGS and standard flow cytometry for MRD detection, with a kappa coefficient of 0.85 indicating almost perfect agreement between the two methods.
In addition, this study found that NGS was able to detect clonal evolution in some patients, which may have implications for treatment decisions and patient outcomes.
Overall, the study suggests that NGS may be a useful tool for monitoring MRD in the bone marrow of multiple myeloma patients, and that it has a high sensitivity and concordance with standard flow cytometry for MRD detection. The study also suggests that NGS may be useful for detecting clonal evolution in multiple myeloma patients (Rustad & Boyle, 2020).
Other: the study realized by Cho et al. (2022) compare the efficacity of the fragment analysis (FA) technique and next-generation sequencing (NGS) in evaluation of the MRD prognostic value in MM assessment and the both techniques had confirmed that the MRD negativity had being associated with improved progression-free survival (PFS) and overall survival (OS). However, the study also found that NGS was more sensitive than FA in detecting of MRD, and that NGS had a stronger association with improved PFS and OS than FA.
Overall, the study suggests that NGS may be a more sensitive method than FA for detecting MRD in MM patients, and that MRD negativity by NGS is associated with improved outcomes regardless of the type of treatment received [
22].
Other studies have compared the performance of NGS and real-time quantitative PCR (qPCR) in detecting of MRD like the study by Yao et al. (2021) which has been included 50 MM patients who had successfully attained complete or partial response after treatment and had undergone both NGS and qPCR for MRD assessment. This study found that both NGS and qPCR were highly sensitive in detecting MRD in MM patients, with NGS detecting MRD in 45 out of 50 patients (90%) and qPCR detecting MRD in 43 out of 50 patients (86%) and found a strong agreement between NGS and qPCR results, with a correlation coefficient of 0.92.
The study also found that NGS had a higher specificity compared to qPCR, with no false-positive results observed in the NGS analysis. Moreover, the study found that NGS was able to detect MRD in a higher proportion of patients with low-level disease compared to qPCR, indicating a higher sensitivity of NGS in detecting low-level disease.
Finally, the study showed that NGS was able to detect clonal evolution and the emergence of new mutations in some patients, which could have implications for treatment decisions and monitoring of disease progression.
Overall, the study suggests that NGS is a highly sensitive and specific method for MRD detection in MM and may offer advantages over qPCR in detecting low-level disease and identifying clonal evolution [
65].
In 2019 Yao et al. aimed to develop a standardized NGS-based MRD assay for multiple myeloma and evaluate its sensitivity and specificity. They analyzed bone marrow samples from 40 multiple myeloma patients using an NGS-based MRD assay targeting patient-specific somatic mutations and found that the NGS-based MRD assay had a sensitivity of 0.001% and a specificity of 100%. MRD was detected in 22 out of 40 (55%) patients using the NGS-based assay, compared to 16 out of 40 (40%) patients using traditional methods such as flow cytometry or ASO-qPCR. The study also demonstrated that the NGS-based MRD assay was reproducible and had a fast turnaround time. The authors concluded that the NGS-based MRD assay could be a reliable tool for MRD detection in multiple myeloma patients [
66].
And in 2020 Yao et al. aimed to develop an upgraded version of the previously developed standardized NGS-based MRD assay for multiple myeloma and evaluate its sensitivity and specificity. The authors analyzed bone marrow samples from 166 multiple myeloma patients using the upgraded NGS-based MRD assay targeting patient-specific somatic mutations. The study found that the upgraded NGS-based MRD assay had a sensitivity of 0.001% and a specificity of 100%. MRD was detected in 103 out of 166 (62%) patients using the upgraded NGS-based assay, compared to 51 out of 166 (31%) patients using traditional methods such as flow cytometry or ASO-qPCR. The study also showed that the upgraded NGS-based MRD assay was reproducible and had a fast turnaround time.
The authors concluded that the upgraded NGS-based MRD assay could be a reliable tool for MRD detection in multiple myeloma patients and has the potential to guide treatment decisions and predict outcomes in clinical practice [
67].
6.5. The Use of WGS and In-House Panels in the Diagnosis of MM
Whole genome sequencing allows for the comprehensive analysis of an individual’s complete genetic code, including mutations and variations in the DNA sequence. In multiple myeloma, WGS has been used to identify somatic mutations and chromosomal aberrations that are associated with the disease. These genetic changes can be used to develop personalized treatment plans and improve patient outcomes.
In addition to WGS, Gene panels are a targeted sequencing approach that focuses on a panel of genes that are known to be associated with MM or other hematologic malignancies. Gene panels typically include genes involved in oncogenesis, DNA repair, cell cycle regulation, and other biological processes that are relevant to cancer development and progression.
A large cohort of 2161 was studied by Walker, Samur, et al. (2016) and focused on the use of WGS, WES and RNAseq to establish a strategy for the Clinical Classification of Multiple Myeloma to segment the disease into therapeutically meaningful subgroups. Actually 5 translocation groups effecting prognosis have been elucidated: t(4;14), t(6;14), t(11;14), t(14;16) and t(14;20) but minor translocation and mutational groups need a sensitive technology as WGS to be detected [
51].
Another study of Ashby et al. (2018) included a cohort of 1141 NDMM and used WGS as well as WES based on previous karyotype information in order to study the presence of hyperhaploidy related to poor prognosis (Double-Hit Bi-Allelic Inactivation of
TP53). [
39]
.
One study made by Raab et al. (2020) about the phase II clinical trial investigated the effectiveness of a combination of BRAF/MEK inhibitors in patients with relapsed/refractory multiple myeloma (RRMM) who had activating BRAF V600E mutations. This study used WGS and phospho-IHC to explore the therapeutic efficacy of the combination between Encorafenib and Binimetinib. The results showed that phospho-IHC was more effective in proving that pharmacodynamic markers reveal suppression of BRAF/MEK signaling et cycle 1/day 28 and restoration of expression at the time of the relapse [
68].
Table 3.
Studies that have used WGS for Diagnosis of MM.
Table 3.
Studies that have used WGS for Diagnosis of MM.
Study |
Year |
Country |
Number of cases |
Type of patients |
Type of samples |
Type of NGS investigation |
[69] |
2021 |
New York, NY |
1154 |
- |
- |
WGS and WES |
[68] |
2020 |
Heidelberg, Germany |
15 |
RRMM |
- |
Exploratory biomarker assessments include cytogenetics, genomic analysis (WGS, RNAseq) and phospho-IHC. |
[70] |
2019 |
New York, USA |
154 |
- |
BM |
WGS with myTYPE panel |
[71] |
2018 |
New York, USA |
- |
- |
BM |
WGS using myTYPE panel |
[39] |
2018 |
Arkansas USA |
1141 |
|
|
WGS, WES, and targeted panel sequencing |
[72] |
2018 |
Little Rock, AR |
439 |
NDMM |
- |
WGS, WES or targeted panel (TP) modalities. |
[73] |
2017 |
St. Louis MO |
995 |
- |
- |
WGS (were identified using custom Seq-FISH software on long-insert whole genome sequencing data.) |
[42] |
2017 |
Boston MA |
186 |
- |
- |
WES and WGS libraries were constructed with Agilent SureSelect XT2 library prep kit, |
[51] |
2016 |
Little Rock, AR |
2161 |
- |
- |
WGS, WES, targeted panel sequencing, expression data from RNA-Seq and Gene Expression array |
[74] |
2016 |
New York, USA |
- |
- |
- |
WGS |
[59] |
2015 |
Boston, MA, USA |
29 |
- |
- |
WGS, (22 patients) WES (17 patients) |
[75] |
2014 |
Phoenix, AZ |
- |
- |
- |
WGS |
[76] |
2012 |
London, UK |
13 |
MM, SMM |
BM |
WGS |
[56] |
2012 |
London, UK |
- |
- |
BM |
WGS, WES, SNVs |
The studies identified several genes that were frequently mutated in multiple myeloma, including TP53, KRAS, NRAS, and BRAF.
Overall, practice of WGS in the diagnosis and management of multiple myeloma has shown great promise. As the technology continues to advance, it is likely that WGS will become an increasingly important tool in the diagnosis and treatment of this complex disease.
Table 4.
Studies that have used myTYPE Panel for Diagnosis of MM.
Table 4.
Studies that have used myTYPE Panel for Diagnosis of MM.
Study |
Year |
Country |
Number of cases |
type of samples |
Type of NGS investigations |
[77] |
2022 |
Stockholm Sweden |
159 |
- |
NGS MRD assay with myTYPE panel |
[78] |
2020 |
New York USA |
74 |
- |
NGS-based assay with myTYPE panel |
[70] |
2019 |
New York, USA |
154 |
BM |
WGS with myTYPE panel |
[71] |
2018 |
New York, USA |
- |
BM |
WGS using myTYPE panel |
[79] |
2018 |
New York USA |
147 |
BM |
NGS assay based myTYPE panel |
[80] |
2018 |
Trondheim, Norway |
177 |
BM |
LymphoTrack® VDJ assay NGS based myTYPE panel assay |
Three studies were leaded by Hultcrantz et Al in 2018, 2020 and 2022 about usage of MyType Panel multiple myeloma diagnosis (Table 5). The first study of 2018 published in
Blood Journal [
79] compared the adaptive NGS VDJ assay and the internal NGS panel myTYPE and concluded that the assay was less sensitive in samples with insufficient DNA content. The last study of 2022 published in
Clinical Cancer Research journal [
77] has been conducted at
Memorial Sloan Kettering Cancer Center (MSK) between 2010 and 2017 and has also focused on the comparison of MyType Panel with Adaptive next generation sequencing (NGS) MRD. The results were similar to the first study( MyType panel had significantly higher V(D)J clonotype detection rates in univariate and multivariate analysis.
Two studies published in the
Blood Cancer Journal in 2019 and 2018 by Yellapantula et Al used both whole genome sequencing and MyType Panel.
The first study of 2018 [
71] compared in one hand MyType Panel and WGS especially in deletions of 1p, 13p, 16q, 17p and gains of 1q, 11q and concluded a total concordance of these aberrations with a percentage of 100% identified by both assays. In The second hand, this study compared MyTYPE panel with FISH and the results were additional t(11;14) translocations identified uniquely by myTYPE. FISH was also used in deletions of 17q, 13q, 1p and 1q gain. All aberrations identified by FISH were identified in myTYPE but 13q- in four samples and 1p- in one sample were uniquely identified by myTYPE and concluded that evaluation of specificity and sensitivity require larger clinical cohort. This team leaded then
a larger.
Therefore, considering the findings of these investigations collectively, it can be inferred that NGS is a remarkably accurate and precise method for identifying minimal residual disease (MRD) in individuals with multiple myeloma.
Some studies have shown that NGS-based assays have a high success rate in characterizing clonality and detecting MRD in plasma cell neoplasms (C. Ho et al., 2018; Rustad et al., 2018) and others demonstrated that NGS can achieve a sensitivity of 10-6 or better, which is superior to other techniques such as PCR and flow cytometry (Yao et al., 2019).
Furthermore, several studies have compared the performance of NGS with other MRD detection methods, such as flow cytometry and PCR, and found that NGS provides higher sensitivity and specificity for MRD detection (Cho et al., 2022b; Medina et al., 2020b).
Overall, these studies suggest that NGS is a highly accurate and reliable method for MRD detection in multiple myeloma patients, and may be used to guide treatment decisions and predict patient outcomes.