Delayed diagnosis resulting in increased disease burden in multiple myeloma: the legacy of the COVID-19 pandemic.

The COVID-19 pandemic has had global healthcare impacts, including high mortality from SARS-CoV-2 infection in cancer patients; individuals with multiple myeloma (MM) are especially susceptible to poor outcomes. However, even for MM patients who avoided severe infection, the ramifications of the pandemic have been considerable. The consequences of necessary socio-geographical behavior adaptation, including prolonged shielding and interruptions in delivery of non-pandemic medical services are yet to be fully understood. Using a real-world dataset of 323 consecutive newly diagnosed MM patients in England, we investigated the impact of the COVID-19 pandemic on routes to myeloma diagnosis, disease stage at presentation and relevant clinical outcomes. We demonstrate increasing MM presentations via emergency services and increased rates of bony and extra-medullary disease. Differences were seen in choice of induction therapy and the proportion of eligible patients undertaking autologous stem cell transplantation. Whilst survival was statistically inferior for emergency presentations, significant survival differences have yet to be demonstrated for the entire cohort diagnosed during the pandemic, making extended follow-up critical in this group. This dataset highlights wide-ranging issues facing MM patients consequent of the COVID-19 pandemic, with full impacts for clinicians and policy-makers yet to be elucidated.

Association of genetic variants with patient reported quality of life and pain experience in patients in the UK NCRI Myeloma X Relapse [Intensive]) trial; an exploratory study.

The Myeloma X trial provided a platform to explore genetics in relation to systematic assessment of patient-reported outcomes at key points during salvage treatment in multiple myeloma (MM) patients. Blood DNA was obtained in 191 subjects for single nucleotide polymorphism (SNP) genotyping. By univariable analysis, the non-coding rs2562456 SNP, upstream of LINC00664, was associated with several relevant pain and health-related quality-of-life (HRQoL) scores at 100 days after allocation to consolidation with autologous stem cell transplantation or weekly cyclophosphamide. Presence of the minor (C) allele was associated with lower pain interference (p = 0.014) and HRQoL pain (p = 0.003), and higher HRQoL global health status (p = 0.011) and physical functioning (p = 0.007). These effects were not modified by treatment arm and were no longer significant at 6 months. Following induction therapy, the rs13361160 SNP near the CCT5 and FAM173B genes was associated with higher global health (p = 0.027) and physical functioning (p = 0.013). This exploratory study supports associations between subjective parameters in MM with SNPs previously identified in genome-wide association studies of pain. Conversely, SNPs in candidate genes involved in opioid and transporter pathways showed no effect. Further studies are warranted in well-defined cancer populations, and potentially assisted by whole genome sequencing with germline analysis in routine diagnostics in haematological cancers.

The impact of cytogenetics on duration of response and overall survival in patients with relapsed multiple myeloma (long-term follow-up results from BSBMT/UKMF Myeloma X Relapse [Intensive]): a randomised, open-label, phase 3 trial.

The Myeloma X trial (ISCRTN60123120) registered patients with relapsed multiple myeloma. Participants were randomised between salvage autologous stem cell transplantation (ASCT) or weekly cyclophosphamide following re-induction therapy. Cytogenetic analysis performed at trial registration defined t(4;14), t(14;16) and del(17p) as high-risk. The effect of cytogenetics on time to progression (TTP) and overall survival was investigated. At 76 months median follow-up, ASCT improved TTP compared to cyclophosphamide (19 months (95% confidence interval [95% CI] 16-26) vs. 11 months (9-12), hazard ratio [HR]: 0·40, 95% CI: 0·29-0·56, P < 0·001), on which the presence of any single high-risk lesion had a detrimental impact [likelihood ratio test (LRT): P = 0·011]. ASCT also improved OS [67 months (95% CI 59-not reached) vs. 55 months (44-67), HR: 0·64, 95% CI: 0·42-0·99, P = 0·0435], with evidence of a detrimental impact with MYC rearrangement (LRT: P = 0·021). Twenty-one (24·7%) cyclophosphamide patients received an ASCT post-trial, median OS was not reached (95% CI: 39-not reached) for these participants compared to 31 months (22-39), in those who did not receive a post-trial ASCT. The analysis further supports the benefit of salvage ASCT, which may still be beneficial after second relapse in surviving patients. There is evidence that this benefit reduces in cytogenetic high-risk patients, highlighting the need for targeted study in this patient group.

The role of ixazomib as an augmented conditioning therapy in salvage autologous stem cell transplant (ASCT) and as a post-ASCT consolidation and maintenance strategy in patients with relapsed multiple myeloma (ACCoRd [UK-MRA Myeloma XII] trial): study protocol for a Phase III randomised controlled trial.

BACKGROUND: Multiple myeloma (MM) is a plasma cell tumour with an approximate annual incidence of 4500 in the UK. Therapeutic options for patients with MM have changed in the last decade with the arrival of proteasome inhibitors and immunomodulatory drugs. Despite these options, almost all patients will relapse post first-line autologous stem cell transplantation (ASCT). First relapse management (second-line treatment) has evolved in recent years with an expanding portfolio of novel agents, driving response rates influencing the durability of response. A second ASCT, as part of relapsed disease management (salvage ASCT), has been shown to prolong the progression-free survival and overall survival following a proteasome inhibitor-containing re-induction regimen, in the Cancer Research UK-funded National Cancer Research Institute Myeloma X (Intensive) study. It is now recommended that salvage ASCT be considered for suitable patients by the International Myeloma Working Group and the National Institute for Health and Care Excellence NG35 guidance. METHODS/DESIGN: ACCoRd (Myeloma XII) is a UK-nationwide, individually randomised, multi-centre, multiple randomisation, open-label phase III trial with an initial single intervention registration phase aimed at relapsing MM patients who have received ASCT in first-line treatment. We will register 406 participants into the trial to allow 284 and 248 participants to be randomised at the first and second randomisations, respectively. All participants will receive re-induction therapy until maximal response (four to six cycles of ixazomib, thalidomide and dexamethasone). Participants who achieve at least stable disease will be randomised (1:1) to receive either ASCTCon, using high-dose melphalan, or ASCTAug, using high-dose melphalan with ixazomib. All participants achieving or maintaining a minimal response or better, following salvage ASCT, will undergo a second randomisation (1:1) to consolidation and maintenance or observation. Participants randomised to consolidation and maintenance will receive consolidation with two cycles of ixazomib, thalidomide and dexamethasone, and maintenance with ixazomib until disease progression. DISCUSSION: The question of how best to maximise the durability of response to salvage ASCT warrants clinical investigation. Given the expanding scope of oral therapeutic agents, patient engagement with long-term maintenance strategies is a real opportunity. This study will provide evidence to better define post-relapse treatment in MM. TRIAL REGISTRATION: ISRCTN, ISRCTN10038996 . Registered on 15 December 2016.

The effect of salvage autologous stem-cell transplantation on overall survival in patients with relapsed multiple myeloma (final results from BSBMT/UKMF Myeloma X Relapse [Intensive]): a randomised, open-label, phase 3 trial.

BACKGROUND: The Myeloma X trial previously reported improved durability of response (time to disease progression) in patients with relapsed multiple myeloma with salvage autologous stem-cell transplantation (ASCT) compared with oral cyclophosphamide in patients with multiple myeloma relapsing after a first ASCT. We report the final overall survival results of the trial. METHODS: BSBMT/UKMF Myeloma X was a multicentre, randomised, open-label, phase 3 trial done at 51 centres in the UK. Eligible patients with multiple myeloma relapsing after a previous ASCT were re-induced with intravenous bortezomib (1·3 mg/m(2) on days 1, 4, 8, 11), intravenous doxorubicin (9 mg/m(2) per day on days 1-4), and oral dexamethasone (40 mg/day on days 1-4, 8-11, and 15-18 during cycle 1 and days 1-4 during cycles 2-4), with supportive care as per local institutional protocols before randomisation in a 1:1 ratio to either high-dose melphalan (200 mg/m(2)) and salvage ASCT or weekly oral cyclophosphamide (400 mg/m(2) per week for 12 weeks). Randomisation was by permuted blocks stratified by length of first remission and response to re-induction treatment. The primary endpoint was time to disease progression; the study was also powered to detect a difference in the secondary endpoint, overall survival. Further secondary endpoints were the proportion of patients achieving an objective response, progression-free survival, overall survival, toxic effects and safety, pain, and quality of life. Prespecified exploratory endpoints included time to second objective disease progression (PFS2). Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00747877, and the European Clinical Trials Database, number 2006-005890-24, and is now in long-term follow-up. FINDINGS: Between April 16, 2008, and Nov 19, 2012, 297 patients were registered into the study and 174 were randomly assigned to receive either high-dose melphalan and salvage ASCT (n=89) or oral weekly cyclophosphamide (n=85). 173 (58%) of 297 patients relapsed after more than 24 months from first ASCT. 75 (43%) of 174 randomised patients had died at follow-up: salvage ASCT (n=31 [35%]) versus oral weekly cyclophosphamide (n=44 [52%]). Updated time to disease progression shows continued advantage in the salvage ASCT group compared with the weekly cyclophosphamide group (19 months [95% CI 16-26] vs 11 months [9-12]; hazard ratio [HR] 0·45 [95% CI 0·31-0·64] log-rank p<0·0001). Median overall survival was superior in the salvage ASCT group compared with weekly cyclophosphamide group (67 months [95% CI 55-not estimable] vs 52 months [42-60]; log-rank p=0·022; HR 0·56 [0·35-0·90], p=0·0169). Time to second objective disease progression was superior in the salvage ASCT group compared with the weekly cyclophosphamide group (67 months [52-not estimable] vs 35 months [31-43]; HR 0·37 [0·24-0·57], log-rank p<0·0001). During extended follow-up, no further treatment-related or treatment-unrelated adverse events were reported. 15 second primary malignancies were reported in 12 patients (salvage ASCT [n=7] vs oral weekly cyclophosphamide [n=5]). The cumulative incidence of second primary malignancies at 60 months after trial entry was 5·2% (2·1-8·2). INTERPRETATION: Salvage ASCT increases overall survival during consolidation of re-induction treatment in patients with multiple myeloma at first relapse after a first ASCT. The delay of salvage ASCT to third-line treatment or later might not confer the same degree of advantage as seen with salvage ASCT at first relapse. FUNDING: Cancer Research UK, Janssen-Cilag, and Chugai Pharma UK.

High-dose chemotherapy plus autologous stem-cell transplantation as consolidation therapy in patients with relapsed multiple myeloma after previous autologous stem-cell transplantation (NCRI Myeloma X Relapse [Intensive trial]): a randomised, open-label, phase 3 trial.

BACKGROUND: Relapsed multiple myeloma has no standard treatment, and the role of autologous stem-cell transplantation (ASCT) has not been fully defined. We aimed to compare high-dose melphalan plus salvage ASCT with cyclophosphamide in patients with relapsed multiple myeloma who had previously undergone ASCT. METHODS: This multicentre, randomised, open-label, phase 3 study recruited patients aged at least 18 years with multiple myeloma who needed treatment for first progressive or relapsed disease at least 18 months after a previous ASCT from 51 centres across the UK. Before randomisation, eligible patients received bortezomib, doxorubicin, and dexamethasone (PAD) induction therapy and then underwent peripheral blood stem-cell mobilisation and harvesting if applicable. Eligible patients (with adequate stem-cell harvest) were randomly assigned (1:1), using an automated telephone randomisation line, to either high-dose melphalan 200 mg/m(2) plus salvage ASCT or oral cyclophosphamide (400mg/m(2) per week for 12 weeks). Randomisation was stratified by length of first remission or plateau and response to PAD re-induction therapy. The primary endpoint was time to disease progression, analysed by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00747877, and EudraCT, number 2006-005890-24. FINDINGS: Between April 16, 2008, and Nov 19, 2012, 297 patients were registered, of whom 293 received PAD re-induction therapy. Between Aug 26, 2008, and Nov 16, 2012, 174 patients with sufficient PBSCs were randomised to salvage ASCT (n=89) or cyclophosphamide (n=85). After a median follow-up of 31 months (IQR 19-42), median time to progression was significantly longer in the salvage ASCT than in the cyclophosphamide group (19 months [95% CI 16-25] vs 11 months [9-12]; hazard ratio 0·36 [95% CI 0·25-0·53]; p<0·0001). Frequently reported (in >10% of patients) grade 3-4 adverse events with PAD induction, salvage ASCT, and cyclophosphamide were: neutropenia (125 [43%] of 293 patients after PAD, and 63 [76%] of 83 patients in the salvage ASCT group vs 11 [13%] of 84 patients in the cyclophosphamide group), thrombocytopenia (150 [51%] after PAD, and 60 [72%] vs four [5%], respectively), and peripheral neuropathy (35 [12%] after PAD, and none vs none, respectively). INTERPRETATION: This study provides evidence for the improved efficacy of high-dose melphalan plus salvage ASCT when compared with cyclophosphamide in patients with relapsed multiple myeloma eligible for intensive therapy, which might help to guide clinical decisions regarding the management of such patients. FUNDING: Cancer Research UK.

Effects of induction and maintenance plus long-term bisphosphonates on bone disease in patients with multiple myeloma: the Medical Research Council Myeloma IX Trial.

The Medical Research Council Myeloma IX Trial (ISRCTNG8454111) examined traditional and thalidomide-based induction and maintenance regimens and IV zoledronic acid (ZOL) and oral clodronate (CLO) in 1960 patients with newly diagnosed multiple myeloma. Overall survival (OS) and skeletal-related event (SRE) data have been reported for the overall trial population. The present analysis investigated optimal therapy regimens for different patient populations in Myeloma IX. Patients were assigned to intensive or nonintensive treatment pathways and randomized to induction cyclophosphamide, vincristine, doxorubicin, and dexamethasone (CVAD) versus cyclophosphamide, thalidomide, and dexamethasone (CTD; intensive) or melphalan and prednisolone versus attenuated oral CTD (CTDa; nonintensive). Patients were also randomized to ZOL or CLO. In the nonintensive pathway, CTDa produced better responses and lower SRE rates than melphalan and prednisolone. ZOL improved OS compared with CLO independently of sex, stage, or myeloma subtype, most profoundly in patients with baseline bone disease or other SREs. In patients treated for ≥ 2 years, ZOL improved OS compared with CLO from randomization (median not reached for either; P = .02) and also from first on-study disease progression (median, 34 months for ZOL vs 27 months for CLO; P = .03). Thalidomide-containing regimens had better efficacy than traditional regimens, and ZOL demonstrated greater benefits than CLO.

Survival of patients with hematological malignancy admitted to the intensive care unit: prognostic factors and outcome compared to unselected medical intensive care unit admissions, a parallel group study.

Improved survival in patients with hematological malignancy (HM) admitted to the intensive care unit (ICU) has largely been reported in uncontrolled cohorts from single academic institutions. We compared hospital mortality between 147 patients with HM and 147 general medical admissions to five non-specialist ICUs. The proportion of patients surviving to hospital discharge was significantly worse in patients with HM (27% vs. 56%; p < 0.001). Six-month and 1-year survival in patients with HM was 21% and 18%, respectively. HM, greater age, mechanical ventilation (MV) and acute physiology and chronic health evaluation (APACHE) II score were independent predictors of poor outcome. For patients with HM, culture proven infection, age, MV and inotropes were negative predictors. Disease-specific factors including hematological diagnosis, neutropenia, remission status, prior stem cell transplant, time from diagnosis to admission and degree of prior treatment were not predictive. Overall survival of patients with HM was worse than that recently reported from specialist units.

Effects of zoledronic acid versus clodronic acid on skeletal morbidity in patients with newly diagnosed multiple myeloma (MRC Myeloma IX): secondary outcomes from a randomised controlled trial.

BACKGROUND: Bisphosphonates are the standard of care for reducing the risk of skeletal-related events in patients with bone lesions from multiple myeloma. The MRC Myeloma IX study was designed to compare the effects of zoledronic acid versus clodronic acid in newly diagnosed patients with multiple myeloma. Here, we report the secondary outcomes relating to skeletal events. METHODS: Patients (≥18 years) with newly diagnosed multiple myeloma were enrolled from 120 centres in the UK and received intensive or non-intensive antimyeloma treatment. A computer-generated randomisation sequence was used to allocate patients in a 1:1 ratio, through an automated telephone service to intravenous zoledronic acid (4 mg every 21-28 days) or oral clodronic acid (1600 mg/day), and the drugs were continued at least until disease progression. No investigators, staff, or patients were masked to treatment allocation. The primary endpoints--overall survival, progression-free survival, and overall response rate--and adverse events have been reported previously. We assessed between-group differences with Cox proportional hazards models for time to first skeletal-related event and incidence of skeletal-related events. These were defined as fractures, spinal cord compression, radiation or surgery to bone, and new osteolytic lesions. Data were analysed until disease progression. Analyses were by intention to treat. This trial is registered, number ISRCTN68454111. FINDINGS: 1960 patients were randomly assigned and analysed--981 in the zoledronic acid group and 979 in the clodronic acid group. This trial is fully enrolled, and follow-up continues. At a median follow-up of 3·7 years (IQR 2·9-4·7), patients in the zoledronic acid group had a lower incidence of skeletal-related events than did those in the clodronic acid group (265 [27%] vs 346 [35%], respectively; hazard ratio 0·74, 95% CI 0·62-0·87; p=0·0004). Zoledronic acid was also associated with a lower risk of any skeletal-related event in the subsets of patients with (233 [35%] of 668 vs 292 [43%] of 682 with clodronic acid; 0·77, 0·65-0·92; p=0·0038) and without bone lesions at baseline (29 [10%] of 302 vs 48 [17%] of 276 with clodronic acid; 0·53, 0·33-0·84; p=0·0068). Fewer patients in the zoledronic acid group had vertebral fractures than did those in the clodronic acid group (50 [5%] in the zoledronic acid group vs 88 [9%] in the clodronic acid group; p=0·0008), other fractures (45 [5%] vs 66 [7%]; p=0·04), and new osteolytic lesions (46 [5%] vs 95 [10%]; p<0·0001). INTERPRETATION: The results of this study support the early use of zoledronic acid rather than clodronic acid in patients with newly diagnosed multiple myeloma for the prevention of skeletal-related events, irrespective of bone disease status at baseline. FUNDING: Medical Research Council (London, UK), Novartis, Schering Health Care, Chugai, Pharmion, Celgene, and Ortho Biotech.

First-line treatment with zoledronic acid as compared with clodronic acid in multiple myeloma (MRC Myeloma IX): a randomised controlled trial.

BACKGROUND: Bisphosphonates reduce the risk of skeletal events in patients with malignant bone disease, and zoledronic acid has shown potential anticancer effects in preclinical and clinical studies. We aimed to establish whether bisphosphonates can affect clinical outcomes in patients with multiple myeloma. METHODS: Patients of age 18 years or older with newly diagnosed multiple myeloma were enrolled from 120 centres in the UK. Computer-generated randomisation sequence was used to allocate patients equally, via an automated telephone service, to receive 4 mg zoledronic acid as an infusion every 3-4 weeks or 1600 mg oral clodronic acid daily. Patients also received intensive or non-intensive induction chemotherapy. No investigators, staff, or patients were masked to treatment allocation, and bisphosphonate and maintenance therapy continued at least until disease progression. The primary endpoints were overall survival, progression-free survival, and overall response rate. We assessed between-group differences with Cox proportional hazards models for progression-free survival and overall survival, and with logistic regression models for overall response rate. Analysis was by intention to treat. This trial is registered, number ISRCTN68454111. FINDINGS: 1970 patients were enrolled between May, 2003, and November, 2007, of whom 1960 were eligible for intention-to-treat analysis: 981 in the zoledronic acid group (555 on intensive chemotherapy, 426 on non-intensive chemotherapy); and 979 on clodronic acid (556 on intensive chemotherapy, 423 on non-intensive chemotherapy). The treatment cutoff was Oct 5, 2009, with patients receiving bisphosphonates for a median of 350 days (IQR 137-632) before disease progression, with a median of 3·7 years' follow-up (IQR 2·9-4·7). Zoledronic acid reduced mortality by 16% (95% CI 4-26) versus clodronic acid (hazard ratio [HR] 0·84, 95% CI 0·74-0·96; p=0·0118), and extended median overall survival by 5·5 months (50·0 months, IQR 21·0 to not reached vs 44·5 months, IQR 16·5 to not reached; p=0·04). Zoledronic acid also significantly improved progression-free survival by 12% (95% CI 2-20) versus clodronic acid (HR 0·88, 95% CI 0·80-0·98; p=0·0179), and increased median progression-free survival by 2·0 months (19·5 months, IQR 9·0-38·0 vs 17·5 months, IQR 8·5-34·0; p=0·07). Rates of complete, very good partial, or partial response did not differ significantly between the zoledronic acid and clodronic acid groups for patients receiving intensive induction chemotherapy (432 patients [78%] vs 422 [76%]; p=0·43) or non-intensive induction chemotherapy (215 [50%] vs 195 [46%]; p=0·18). Both bisphosphonates were generally well tolerated, with similar occurrence of acute renal failure and treatment-emergent serious adverse events, but zoledronic acid was associated with higher rates of confirmed osteonecrosis of the jaw (35 [4%]) than was clodronic acid (3 [<1%]). INTERPRETATION: Consistent with the potential anticancer activity of zoledronic acid, overall survival improved independently of prevention of skeletal-related events, showing that zoledronic acid has treatment benefits beyond bone health. These findings support immediate treatment with zoledronic acid in patients with newly diagnosed multiple myeloma, not only for prevention of skeletal-related events, but also for potential antimyeloma benefits. FUNDING: Medical Research Council (London, UK), with unrestricted educational grants from Novartis, Schering Health Care, Chugai, Pharmion, Celgene, and Ortho Biotech.

Assessment of bone marrow response in Waldenström's macroglobulinemia.

In this study we used bone marrow flow cytometry and immunohistochemistry to evaluate response to fludarabine therapy in patients with Waldenström's macroglobulinemia (WM)/lymphoplasmacytic lymphoma. Responses in serum M protein were typically delayed with a median time to maximum response of 6 months following the completion of therapy (range, 0-18 months). In contrast, bone marrow responses occurred promptly in responding patients such that there were no detectable clonal B cells at the end of therapy in 55% of patients assessed. Persistent monoclonal plasma cells were, however, readily identified by CD138 immunohistochemistry, explaining the persistence of serum M protein in these patients. This simple observation has significant implications for the assessment of responses in WM as well as the design of future therapeutic strategies.

Insights into the multistep transformation of MGUS to myeloma using microarray expression analysis.

To define specific pathways important in the multistep transformation process of normal plasma cells (PCs) to monoclonal gammopathy of uncertain significance (MGUS) and multiple myeloma (MM), we have applied microarray analysis to PCs from 5 healthy donors (N), 7 patients with MGUS, and 24 patients with newly diagnosed MM. Unsupervised hierarchical clustering using 125 genes with a large variation across all samples defined 2 groups: N and MGUS/MM. Supervised analysis identified 263 genes differentially expressed between N and MGUS and 380 genes differentially expressed between N and MM, 197 of which were also differentially regulated between N and MGUS. Only 74 genes were differentially expressed between MGUS and MM samples, indicating that the differences between MGUS and MM are smaller than those between N and MM or N and MGUS. Differentially expressed genes included oncogenes/tumor-suppressor genes (LAF4, RB1, and disabled homolog 2), cell-signaling genes (RAS family members, B-cell signaling and NF-kappaB genes), DNA-binding and transcription-factor genes (XBP1, zinc finger proteins, forkhead box, and ring finger proteins), and developmental genes (WNT and SHH pathways). Understanding the molecular pathogenesis of MM by gene expression profiling has demonstrated sequential genetic changes from N to malignant PCs and highlighted important pathways involved in the transformation of MGUS to MM.

Polymorphic variation in GSTP1 modulates outcome following therapy for multiple myeloma.

Glutathione S-transferase P1 (GSTP1) is a phase 2 drug metabolism enzyme involved in the metabolism and detoxification of a range of chemotherapeutic agents. A single nucleotide polymorphism (Ile105Val) results in a variant enzyme with lower thermal stability and altered catalytic activity. We hypothesized that patients with the less stable variant have a decreased ability to detoxify chemotherapeutic substrates, including melphalan, and have an altered outcome following treatment for multiple myeloma. We have assessed the impact of GSTP1 codon 105 polymorphisms in 222 patients entered into the Medical Research Council (MRC) myeloma VII trial (comparing standard-dose chemotherapy with high-dose therapy). In the standard-dose arm, patients with the variant allele (105Val) had an improved progression-free survival (PFS) (adjusted hazard ratios for PFS were 0.55 for heterozygotes and 0.52 for 105Val homozygotes, compared with 105Ile homozygotes; P for trend =.04); this was supported by a trend to improved overall survival, greater likelihood of entering plateau and shorter time to reach plateau in patients with the 105Val allele. No difference in outcome by genotype was found for patients treated with high-dose therapy. However, the progression-free survival advantage of the high-dose arm was seen only in patients homozygous for 105Ile (P =.008).

Genomic characterization of the chromosomal breakpoints of t(4;14) of multiple myeloma suggests more than one possible aetiological mechanism.

Using FISH-based techniques, rearrangements of the immunoglobulin heavy-chain (IgH) locus at 14q32 have been found in the majority of cases of multiple myeloma (MM). Some of these IgH translocations are recurrent and we have characterized the genomic breakpoints of seven t(4;14) translocations from MM patients, using a combination of vectorette and conventional polymerase chain reaction methods, the aim being to understand the molecular mechanism leading to MM. Conventionally, the chromosome 14q32 breakpoints in these reciprocal translocations are believed to be located in the IgH mu switch (S) region and a further downstream S region with deletion of intervening DNA occurring as a result of aberrant class switch recombination (CSR); this was seen in five of the cases analysed. However, in two patients it was possible to demonstrate that the rearranged hybrid switch region sequence was joined to DNA from chromosome 4p16, suggesting that IgH translocations can occur in B cells that have already undergone legitimate CSR. The complex nature of these rearrangements leads us to speculate that primary IgH translocations may occur at different time points in the development in MM plasma cells, either at the time of physiological CSR or at a later stage, possibly involving a different mechanism.

Flow cytometric disease monitoring in multiple myeloma: the relationship between normal and neoplastic plasma cells predicts outcome after transplantation.

Conventional monitoring strategies for myeloma are not sufficiently sensitive to identify patients likely to benefit from further therapy immediately after transplantation. We have used a sensitive flow cytometry assay that quantitates normal and neoplastic plasma cells to monitor the bone marrow of 45 patients undergoing high-dose chemotherapy. Neoplastic plasma cells were detectable at 3 months after transplantation in 42% of patients. Once detected, neoplastic cell levels increased steadily until clinical progression: these patients had a significantly shorter progression-free survival (PFS) (median, 20 months) than those with no detectable disease (median, longer than 35 months; P =.003). Neoplastic plasma cells were detectable in 27% (9 of 33) of immunofixation-negative complete-remission patients. These patients had a significantly shorter PFS than immunofixation-negative patients with no detectable neoplastic plasma cells (P =.04). Normal plasma cells were present in 89% of patients immediately after transplantation, but were not sustained in most cases. Patients with only normal phenotype plasma cells present at 3 months after transplantation and also at second assessment had a low risk of disease progression. Patients with neoplastic plasma cells present at 3 months after transplantation, or with only normal plasma cells present at first assessment and only neoplastic plasma cells at second assessment, had a significantly higher risk of early disease progression (P <.0001) with a 5-year survival of 54% for the high-risk group, compared with 100% in the low-risk group (P =.036). Analysis of normal and neoplastic plasma cell levels is more sensitive than immunofixation and can identify which patients may benefit from additional treatment strategies at an early stage after transplantation.