Expert review on soft-tissue plasmacytomas in multiple myeloma: definition, disease assessment and treatment considerations.

In this review, two types of soft-tissue involvement in multiple myeloma are defined: (i) extramedullary (EMD) with haematogenous spread involving only soft tissues and (ii) paraskeletal (PS) with tumour masses arising from skeletal lesions. The incidence of EMD and PS plasmacytomas at diagnosis ranges from 1·7% to 4·5% and 7% to 34·4% respectively. EMD disease is often associated with high-risk cytogenetics, resistance to therapy and worse prognosis than in PS involvement. In patients with PS involvement a proteasome inhibitor-based regimen may be the best option followed by autologous stem cell transplantation (ASCT) in transplant eligible patients. In patients with EMD disease who are not eligible for ASCT, a proteasome inhibitor-based regimen such as lenalidomide-bortezomib-dexamethasone (RVD) may be the best option, while for those eligible for high-dose therapy a myeloma/lymphoma-like regimen such as bortezomib, thalidomide and dexamethasone (VTD)-RVD/cisplatin, doxorubicin, cyclophosphamide and etoposide (PACE) followed by SCT should be considered. In both EMD and PS disease at relapse many strategies have been tried, but this remains a high-unmet need population.

Assessment of Sclerodermoid Chronic Graft-versus-host Disease with Colour Doppler Ultrasound.

Sclerodermoid chronic graft-versus-host disease (scGVHD) is a severe complication of allogeneic haema-- topoietic stem cell transplantation. The aim of this study was to investigate the usefulness of high-frequency ultrasound of the skin in assessing the inflammatory patterns and prognosis of patients with scGVHD. A prospective study was carried out with patients who developed scGVHD in the period June 2016 to April 2018. Clinical and ultrasound examinations were performed on the first visit and at 6-month follow-up. A total of 24 patients were included in the study. A 6-month follow-up high-frequency ultrasound of the skin was performed on 20 of the 24 patients. Abnormal B-mode findings in high-frequency ultrasound of the skin consisted of hypoechogenic dermis, hypoechogenicity of septa and hyperechogenicity of lobules in hypodermis. No differences were observed in these basal parameters between treatment progressive/non-responding and inactive/responding scGVHD groups of patients. Basal Doppler showing increased vascular flow with a systolic peak ≥10 cm/s and a vascular resistance index ≥ 0.70 was observed only in those patients who developed progressive/non-responding scGVHD (62.5% vs 0% p = 0.006). In conclusion, Doppler ultrasound is a useful tool to assess the inflammatory activity and outcome of scGVHD. These findings could enhance patient management and help to guide treatment decisions.

Comparison of next-generation sequencing (NGS) and next-generation flow (NGF) for minimal residual disease (MRD) assessment in multiple myeloma.

Detecting persistent minimal residual disease (MRD) allows the identification of patients with an increased risk of relapse and death. In this study, we have evaluated MRD 3 months after transplantation in 106 myeloma patients using a commercial next-generation sequencing (NGS) strategy (LymphoTrack®), and compared the results with next-generation flow (NGF, EuroFlow). The use of different marrow pulls and the need of concentrating samples for NGS biased the applicability for MRD evaluation and favored NGF. Despite that, correlation between NGS and NGF was high (R2 = 0.905). The 3-year progression-free survival (PFS) rates by NGS and NGF were longer for undetectable vs. positive patients (NGS: 88.7% vs. 56.6%; NGF: 91.4% vs. 50%; p < 0.001 for both comparisons), which resulted in a 3-year overall survival (OS) advantage (NGS: 96.2% vs. 77.3%; NGF: 96.6% vs. 74.9%, p < 0.01 for both comparisons). In the Cox regression model, NGS and NGF negativity had similar results but favoring the latter in PFS (HR: 0.20, 95% CI: 0.09-0.45, p < 0.001) and OS (HR: 0.21, 95% CI: 0.06-0.75, p = 0.02). All these results reinforce the role of MRD detection by different strategies in patient prognosis and highlight the use of MRD as an endpoint for multiple myeloma treatment.

Role of urine immunofixation in the complete response assessment of MM patients other than light-chain-only disease.

Response criteria for multiple myeloma (MM) require monoclonal protein (M-protein)-negative status on both serum immunofixation electrophoresis (sIFE) and urine (uIFE) immunofixation electrophoresis for classification of complete response (CR). However, uIFE is not always performed for sIFE-negative patients. We analyzed M-protein evaluations from 384 MM patients (excluding those with light-chain-only disease) treated in the GEM2012MENOS65 (NCT01916252) trial to determine the uIFE-positive rate in patients who became sIFE-negative posttreatment and evaluate rates of minimal residual disease (MRD)-negative status and progression-free survival (PFS) among patients achieving CR, CR but without uIFE available (uncertain CR; uCR), or very good partial response (VGPR). Among 107 patients with M-protein exclusively in serum at diagnosis who became sIFE-negative posttreatment and who had uIFE available, the uIFE-positive rate was 0%. Among 161 patients with M-protein in both serum and urine at diagnosis who became sIFE-negative posttreatment, 3 (1.8%) were uIFE positive. Among patients achieving CR vs uCR, there were no significant differences in postconsolidation MRD-negative (<10-6; 76% vs 75%; P = .9) and 2-year PFS (85% vs 88%; P = .4) rates; rates were significantly lower among patients achieving VGPR. Our results suggest that uIFE is not necessary for defining CR in MM patients other than those with light-chain-only disease.

Clinical applicability and prognostic significance of molecular response assessed by fluorescent-PCR of immunoglobulin genes in multiple myeloma. Results from a GEM/PETHEMA study.

Minimal residual disease monitoring is becoming increasingly important in multiple myeloma (MM), but multiparameter flow cytometry (MFC) and allele-specific oligonucleotide polymerase chain reaction (ASO-PCR) techniques are not routinely available. This study investigated the prognostic influence of achieving molecular response assessed by fluorescent-PCR (F-PCR) in 130 newly diagnosed MM patients from Grupo Español Multidisciplinar de Melanoma (GEM)2000/GEM05 trials (NCT00560053, NCT00443235, NCT00464217) who achieved almost very good partial response after induction therapy. As a reference, we used the results observed with simultaneous MFC. F-PCR at diagnosis was performed on DNA using three different multiplex PCRs: IGH D-J, IGK V-J and KDE rearrangements. The applicability of F-PCR was 91·5%. After induction therapy, 64 patients achieved molecular response and 66 non-molecular response; median progression-free survival (PFS) was 61 versus 36 months, respectively (P = 0·001). Median overall survival (OS) was not reached (NR) in molecular response patients (5-year survival: 75%) versus 66 months in the non-molecular response group (P = 0·03). The corresponding PFS and OS values for patients with immunophenotypic versus non-immunophenotypic response were 67 versus 42 months (P = 0·005) and NR (5-year survival: 95%) versus 69 months (P = 0·004), respectively. F-PCR analysis is a rapid, affordable, and easily performable technique that, in some circumstances, may be a valid approach for minimal residual disease investigations in MM.

Multiple myeloma in serologic complete remission after autologous stem cell transplantation: impact of bone marrow plasma cell assessment by conventional morphology on disease progression.

The current definition of complete remission (CR) in multiple myeloma (MM) requires a negative serum and urine immunofixation (IFE) and <5% bone marrow plasma cells (BMPCs). The aim of this study was to determine the value of BMPCs count by standard microscopic evaluation in patients with MM in serologic CR after autologous stem cell transplantation (ASCT). Thirty-five patients with a median follow-up after ASCT of 7.3 years were studied. The percentage of BMPCs was an independent predictor of progression in multivariate model (hazard ratio 2.02, P = .009). Patients with >1.5% BMPCs (median: 0.8%) after ASCT had an increased risk of progression (P = .016) and a trend toward a shorter survival (P = .195). In conclusion, conventional morphology of bone marrow is a useful and rapid tool as a first step to assess the residual tumor mass in patients with MM in CR after ASCT, and it constitutes a strong predictor for disease progression.