Citations

Abstract Hyperdiploid (>48 chromosomes) multiple myeloma (H-MM) and high hyperdiploid (>50 chromosomes) acute lymphoblastic leukemia (H-ALL) are characterized by aneuploidy and multiple recurrent trisomies (chromosome 3,5,7,9,11,15,19 for H-MM and chromosomes X,4,6,10,14,17,18,21 for H-ALL). Little is known about the oncogenic events, consequences of the trisomies and reasons for the different recurrent trisomies. In an attempt to answer these questions, we undertook a combined gene expression and network/pathway analysis approach. Gene expression data was generated using the Affymetrix U133A chip (Affymetrix, Santa Clara, Ca) for 53 H-MM and 37 non-hyperdiploid MM (NH-MM) cases using CD138-enriched plasma-cell RNA. Gene expression data using the same chip for ALL was obtained from previous published data (Ross ME et al Blood2004; 104: 3679–3687). Analysis was performed using Genespring 7 (Agilent Technologies, Palo Alto, CA). By comparing the median expression of all genes on each chromosome between H-MM/H-ALL and their non-hyperdiploid counterparts (NH-MM and NH-ALL) for the 23 chromosomes (excluding Y), one can clearly identify the commonly trisomic chromosomes in H-ALL and H-MM. However, the relationship of gene expression was highly variable for H-MM and NH-MM as compared to H-ALL and NH-ALL which tended to have expression ratios close to 1 for the non-trisomic chromosomes. Sixty-nine percent of the differentially expressed genes generated by ANOVA analysis (p<0.001) in H-ALL were on the commonly trisomic chromosomes and were upregulated whereas the corresponding figure in H-MM is 40%. These similarities and differences probably reflect both an overall gene dosage effect and the different complexities of the karyotypes of H-MM and H-ALL compared to NH-MM and NH-ALL respectively (MM karyotypes are more complex, hence difference between H and NH-MM is greater and less confined to the trisomic chromosomes). We next performed network analysis using a curated web-based software (MetaCore, GeneGo Inc, St Joseph, MI) using the 2 sets of differentially expressed genes. Majority of genes differentially expressed in H-MM are involved in mRNA translation/protein synthesis whereas the genes differentially expressed in H-ALL were mainly involved in signal transduction. Therefore the transcriptional program that characterize the difference between H and NH-MM/ALL seem to recapitulate normal cellular function: protein synthesis in the mature secretory plasma cells and signal transduction in response to cytokines in a differentiating early-B cell. However, due to the concurrent deregulation of many genes on these trisomic chromosomes, these and other cellular programs are deregulated resulting in malignant transformation. We also intersected the 2 lists of differentially expressed genes to find genes that are up- or downregulated in both H-MM and H-ALL relative to the NH tumors. Thirteen genes including interferon response genes (TNFSF10, MX1, ZNF185) and transcription factors like RUNX1 were upregulated, whereas 13 genes including a cancer testis antigen gene (MAGED4) were downregulated in both H-MM and H-ALL. These genes may point to common oncogenic mechanisms.

Abstract Background: Multiple Myeloma (MM) is characterized by accumulation of malignant plasma cells with relatively low proliferative and apoptotic rates. The proliferative rate of plasma cells, measured in terms of % plasma cells labeled by bromodeoxyuridine (BrdU) using slide based fluorescence microscopy (plasma cell labeling index or PCLI) has been shown to be a powerful prognostic factor in MM. We have previously shown that the % bone marrow plasma cells in apoptosis (PCAP) determined by a flow cytometry method that uses Annexin V staining or 7-amino Actinomycin D (7-AAD) correlates with disease stage in MM. The goal of this study was to examine the prognostic value of the PCAP. Methods: We studied 145 patients with MM including 74 with newly diagnosed MM, 40 with relapsed MM, and 31 with MM on treatment in whom simultaneous measurements of % plasma cell apoptosis and PCLI were available. The PCLI is expressed as the percentage of cytoplasmic immunoglobulin positive plasma cells that have taken up BrdU. The PCLI was characterized as high when >= 1%. Mononuclear cells isolated from bone marrow aspirate, following red cell lysis with ACK solution, are incubated with CD38-PE and either CD138-FITC or CD45-FITC. This is followed by incubation with 7-AAD and the plasma cells are gated using the CD38/CD45 staining pattern. The Annexin method used a similar strategy, with Annexin V in place of 7-AAD. The percentage of plasma cells in apoptosis (PCAP) was categorized as high when >5%, the median value. Results: The median follow up for the entire group was 34 months (range, 0.1 mo to 9 years) and 112 (77%) had died at the time of analysis. Forty seven patients (32%) had a high PCLI (>=1%). The median overall survival for the patients with high PCLI was 14.6 months versus 42.3 months for those with a low PCLI; P = 0.0005 (log rank test). Seventy-five (51.7%) patients had a high PCAP. The median overall survival for those patients was 28.9 months versus 40.2 months for those with a low PCAP; P = 0.078. We next examined if there was any correlation between a high PCAP and high PCLI and found none; P = NS by (Fisher’s exact test). Additionally in a multivariate Cox model using both PCLI and PCAP, both were independently prognostic for overall survival. We then developed an index by adding PCLI to log transformed PCAP (PCLI + log PCAP). Using a cutoff of 1.5 for the new index we were able identify a group of patients with poor survival. The 59 patients with a high value for the new index had a median survival of 19.3 months vs 46.1 months for the rest (P < 0.0001, log rank test). Conclusion: The measurement of plasma cell apoptosis has prognostic value in patients with MM. More importantly, we have shown that by combining measures of two important biological characteristics of the plasma cell, namely proliferation and apoptosis, patients with a poor prognosis can be identified. Such a prognostication strategy can help stratify patients in clinical trials as well as shed light on the disease biology.

Abstract Chromosome 13 deletion (Δ13) is one the most common genetic abnormalities observed in multiple myeloma (MM) and confers a poor prognosis. Studies to identify critical tumor suppressor genes in MM till date have lack adequate resolution, and the molecular phenotype associated with Δ13 has not been established. In this study we seek to establish a molecular profile for Δ13 and to finely map the minimal common region of deletion (CDR) on chromosome 13 by using gene expression profiling (GEP) and array comparative genomic hybridization (aCGH). GEP was performed on RNA from purified plasma cells of 72 newly diagnosed MM and 50 human myeloma cell lines (HMCLs) using the Affymetrix U133A chip and U133plus chip (Affymetrix, Santa Clara, CA) respectively. Patients were assigned TC classes which correlates with underlying genetic subtypes. In addition, aCGH was performed on 79 MM samples (36 with GEP data) and 50 myeloma cell lines (HMCLs; 48 with GEP data) using a platform utilizing 60-mer oligonucleotides (Human Genome CGH 44B Oligo Microarrays, Agilent Technologies), which have a resolution of about 70Kb. Raw data was extracted using the Feature Extraction 8.1 and visualized using CGH Analytics 3.2 (Agilent Technologies). To define a signature that reflects the biological consequences of Δ13 and not its close association with some genetic subtypes of MM (example, t(4;14) and t(14;16)), we selected a training cohort consisting of cases belonging to D1, D2, 11q13 and none TC class such that cases with and without Δ13 are balanced for ploidy and TC classes (n=28). A 152-gene Δ13 signature was identified. Its specificity was confirmed by leave-one-out cross validation using the K-nearest neighbor (KNN) class prediction algorithm (predictive accuracy of 100% in the training cohort). It was subsequently validated in a validation cohort that includes t(4;14) and t(14;16) that were not use to derive this gene signature, maintaining a high predictive accuracy (88%). This gene-set may therefore reflect core transcriptional consequences of Δ13 and is enriched for genes involved in the cell cycle and apoptosis. Using aCGH, 20 patients have Δ13 (mostly whole chromosome) all involving the 13q14–q21 region. Of the 32 HMCLs with Δ13 (whole chromosome or interstitial), 22 have mono-allelic loss of RB1 whereas 4 had bi-allelic loss. Besides RB1, bi-allelic loss of several other genes in the 13q14–q21 region (CYSLTR2, CDADC1, ITM2B, PCDH9) was also observed. As the CDR is large and contains a number of genes, we utilized a set of criteria (bi-allelic loss in HMCLs, within 13q14–q21 CDR, gene expression significantly correlated with copy number, and loss could explain molecular phenotype) to narrow down the potential candidates. Only RB1 and ITM2B fulfilled these criteria. Furthermore, RB protein levels correlated well with mRNA levels and DNA copy suggesting that even in absence of mutations resulting in bi-allelic loss, mono-allelic loss of RB1 could be tumorigenic through a haploinsufficiency mechanism.

Abstract Background: Primary systemic amyloidosis (AL) is an incurable plasma cell disorder. Lenalidomide, especially in conjunction with dexamethasone, has been shown to be highly active in patients with multiple myeloma. Methods: We studied the toxicity and efficacy of lenalidomide in patients with symptomatic AL. Patients received single agent lenalidomide. If progression by 3 months or no evidence of hematologic response after 3 cycles, dexamethasone was added. Originally, twenty-three patients (Cohort 1) were enrolled according to study design. Because of a significant early drop out rate and notable activity of the regimen, the trial was modified to include an additional 15 patients (Cohort 2). Baseline characteristics and adverse events are available for all enrolled patients, but at the time of this writing, response data are available for Cohort 1 patients due to short follow-up of Cohort 2, but will be updated by the time of the meeting. Results: Median age was 64 years, with 69% male. Twenty-three were previously treated. Organ involvement was cardiac (67%), renal (64%), hepatic (17%), nerve (17%). Thirty-three, twenty-two, and forty-four percent of patients were cardiac biomarker stage 1, 2, and, 3 respectively. Of the 37 patients, one was a cancel, and 6 have not yet made it through 3 months of protocol treatment and event monitoring. The respective median follow-ups for Cohorts 1 and 2 are 17 and 3.4 months. Of the remaining, 30 patients, within the first 3 cycles of therapy fifteen patients discontinued treatment: 7 early deaths and 8 adverse events or other causes. Three additional patients died 0.5 to 2 months after stopping treatment. The best predictor for early withdrawal and/or death was baseline NT-proBNP and cardiac biomarker staging system (cut-offs for serum troponin T <0.035 ng/ml and NT-proBNP <332 pg/ml--Stage I neither above cut-off; Stage III, both above cut-off; and Stage II, one above cut-off). Figure1 Figure1. Figure 2 Figure 2. Of the twenty 22 patients assessed for response ten patients responded to treatment for an overall response rate of 45%, including 23% organ responders. Among the patients with organ responses, there were four renal responses, two cardiac responses and two liver responses. All but one of the responders had dexamethasone added to their treatment program. The most common grade 3−4 adverse events at least possibly attributable to lenalidomide were neutropenia (38%), thrombocytopenia (21%), fatigue (15%), and rash (12%). Conclusions: Lenalidomide and dexamethasone has significant activity in patients with AL with an overall response rate of 45%. Baseline NT−proBNP may be an effective eligibility screening strategy for subsequent trials.

Abstract Hyperdiploid MM (H-MM), characterized by recurrent trisomies constitute about 50% of MM, yet very little is known about its pathogenesis and oncogenic mechanisms. Studies in leukemia and solid tumors have shown gene dosage effect of aneuploidy on gene expression. To determine the possible gene dosage effect and deregulated cellular program in H-MM we undertook a gene expression study of CD138-enriched plasma-cell RNA from 53 hyperdiploid and 37 non-hyperdiploid MM (NH-MM) patients using the Affymetrix U133A chip (Affymetrix, Santa Clara, CA). Gene expression data was analyzed using GeneSpring 7 (Agilent Technologies, Palo Alto, CA). Genes differentially expressed between H-MM and NH-MM were obtained by t-test (p<0.01). The majority of the differentially expressed genes (57%) were under-expressed in H-MM. Genes located on the commonly trisomic chromosomes were mostly (but not always) over-expressed in H-MM and constitute 76% of over-expressed genes. Chromosome 1 contained the most differentially expressed genes (17%) followed by chromosome 12 (9%), and 19 (8%). To examine the relationship of gene copy number to gene expression, we examined the expression of genes on chromosomes 9 and 15 in subjects with 2 copies (15 normal control and 20 NH-MM) and 3 copies (12 H-MM) of each chromosome as detected by interphase FISH. We then derived a ratio of the mean expression of each gene on these chromosomes between patients with 3 copies and 2 copies of the chromosome. If a simple relationship exists between gene expression and gene copy number, one would expect the ratio of expression of most genes on these two chromosomes to be about 1.5 in H-MM compared to NH-MM. However, many genes have ratios either higher than 2 or lower than 0.5. Furthermore, when the heterogeneity of cells with underlying trisomies is taken into consideration by correcting the ratio for the number of cells with trisomies, the actual ratio is always lower than the expected ratio. When the expression of genes on a chromosome was compressed to a median value, this value was always higher in the trisomic chromosomes for H-MM compared to NH-MM. The data suggests that although gene dosage influence gene expression, the relationship is complex and some genes are more gene dosage dependent than others. Amongst the differentially expressed genes with known function, 33% are involved in mRNA translation/protein synthesis. Of note, 37 of the top 100 differentially expressed genes are involved in these processes. In particular, 60 ribosomal protein (RP) genes are significantly (p<0.05) upregulated in H-MM. This signature in H-MM is not associated with increase proliferation as measured by PCLI. This predominant signature suggests that deregulated protein synthesis may be important for the biology of H-MM. Many of these RPs are involved in the synthesis of product of oncogenic pathways (e.g. MYC, NF-KB pathways) and may mediate the growth and survival of tumor cells. It is therefore possible that these tumor cells may be sensitive to the disruption of mRNA translation/protein synthesis. Targeting the mTOR pathway with rapamycin may therefore be useful for treatment of H-MM.

Abstract Background: The serum free light chain (FLC) assay is increasingly used to monitor patients (pts) with oligo-secretory or non-secretory multiple myeloma (MM) and pts with primary amyloidosis lacking measurable monoclonal protein in the serum or urine. Criteria to use this assay to assess response to therapy have recently been proposed (Rajkumar SV, Kyle RA. Best Pr Clin Haematol2005;18:585–601) but have not been validated. The goal of this study was to validate the response criteria for the FLC assay in a prospective trial of lenalidomide plus dexamethasone in newly diagnosed MM. Methods: 34 pts were enrolled in the trial; 27 pts who had serial FLC assessments were studied. FLC estimation was carried out using the serum FLC assay (FreeliteH, The Binding Site Limited, UK) performed on a Dade-Behring Nephelometer. Pts with κ /λ FLC ratio <0.26 were defined as having monoclonal λ FLC and those with ratios >1.65 as having a monoclonal κ FLC. The monoclonal light chain isotype was considered the “involved” FLC isotype, and the opposite light chain type as the “uninvolved” FLC type. Partial response (PR) required an abnormal baseline FLC ratio and any one of the two following criteria: 1) a 50% decrease in the level of the involved FLC plus a 50% decrease (or normalization) in the ratio of involved/uninvolved FLC or 2) 50% decrease in the difference between involved and uninvolved FLC levels. Complete response (CR) required normalization of FLC ratio and negative serum and urine immunofixation. Response at 4 months or earlier by the Bladé criteria was compared to FLC response criteria from the same evaluation. Results: Three pts had normal FLC levels and ratio and were not included in the analysis. 23 of the remaining 24 achieved a PR or better by Bladé criteria. A 50% decrease in the level of the involved FLC plus a 50% decrease (or normalization) in the ratio of involved/uninvolved FLC correctly classified 20 of the 22 responding pts (sensitivity 91%); 2 pts could not be evaluated since baseline FLC ratio could not be calculated. On the other hand, a 50% decrease in the mathematical difference between involved and uninvolved FLC levels correctly classified all 24 responding pts (sensitivity 100%). The one non-responding pt by Blade criteria was correctly classified by both FLC criteria. All pts were correctly classified by both criteria when only those with a baseline “involved” FLC level of at least ≥10mg/dL (≥100mg/L) were considered (15 pts). Conclusions: This study demonstrates that the serum FLC assay can be used to assess response to therapy. A 50% decrease in the difference between “involved” and “uninvolved” FLC levels will suffice as FLC criteria for PR, eliminating the need for the alternative criteria based on the involved FLC level and the ratio. We recommend that this FLC response criteria be used only in pts not having measurable levels of serum and /or urine M protein.The FLC response criteria will now enable most patients with oligo-secretory and non-secretory MM to enter trials for which they are currently ineligible due to “lack of measurable serum or urine M protein.” This study is limited by the lack of adequate non-responders to calculate specificity and lack pts who progressed to validate progression criteria and needs further validation.

Abstract Introduction: High dose melphalan followed by autologous stem cell transplantation (ASCT) is an effective treatment for patients with light chain associated (AL) amyloidosis. Longer patient survival and higher rates of organ response have now been documented by multiple studies. However, predictors of organ response remain unknown. Previously, we have reported the benefits of renal response after ASCT in this population. This study was conducted to investigate the characteristics that would predict renal response after ASCT. Methods: The study was performed retrospectively on consecutive patients that underwent ASCT at our institution from March of 1996 to December of 2004. Exclusion criteria include baseline proteinuria < 1 g/d, dialysis prior to ASCT and lack of laboratory data at follow up to determine renal response. Renal response was defined by > 50% reduction in baseline proteinuria with < 25% decline in renal function as measured by serum creatinine. Treatment related mortality and dialysis dependence prior to meeting criteria of response were viewed as treatment failures. Hematologic response was determined by 50% reduction of monoclonal protein (free light chain) or complete eradication if the monoclonal protein was too small to be quantified. Results: A total of 135 patients met criteria for study. Median age was 56.2 years at the time of transplant, 53.7% were male. Median baseline proteinuria and GFR were 6.4 g/d and 70 ml/min/1.73m2 respectively. Renal response was achieved in 35.6% of the patients while hematologic response was 71.1% in the 128 patients evaluated. Patient’s age, sex, albumin, GFR, proteinuria, conditioning regimen, and hematologic response were evaluated and the following were found to be associated with renal response: albumin (p = 0.001), proteinuria (p = 0.008), and hematologic response (p = 0.0002). The cutoff for albumin was found to be 1.6 mg/dl and proteinuria was 3.5 g/d. Multivariate analysis using a logistic regression model showed hematologic response and proteinuria to be independent predictors of renal response. The impact of proteinuria and hypoalbuminemia was then investigated together (Table 1). When combined, they were a better predictor then either one alone (Hazard ratio = 6.34 for combined, 3.43 for proteinuria, 3.32 for hypoalbuminemia). The combination was also a better independent predictor of renal response in the multivariate analysis. In this group of patients, renal response was associated with longer survival but hematologic response was not (p = 0.02). Discussion: Our study showed that besides hematologic response, baseline serum albumin and proteinuria are independent predictors of renal response in AL patients after ASCT. Hypoalbuminemia and nephrotic range proteinuria, both markers of the severity of renal disease, have strong negative impact on response. This implies that there may be a limit to the reversibility of organ damage even when hematologic response is achieved. This study also points out the importance of organ (renal) response in this disease as hematologic response alone did not predict long term outcome. Our results suggest ASCT should be done early for AL to insure optimal organ response and patient outcome. Table 1 The Effects of Hypoalbuminemia and Proteinuria on Renal Response after ASCT Hypoalbuminemia & Proteinuria No Renal Response Renal Response None 39.3% 60.7% One 66.2% 33.8% Both 81.8% 18.2%

Abstract Introduction: Molecular cytogenetic studies have revealed that, to a great extent, the heterogeneity of myeloma is largely dictated by the underlying genetic and cytogenetic aberrations present in the clonal plasma cells. Most recently the group from the University of Arkansas identified strong prognostic associations with an increased level of gene expression of a cell cycle associated gene, CKS1B. CKS1B favors cell cycle progression by promoting degradation of p27 with release of the cyclin dependent kinases and entry into mitosis. Patients and methods: To further test this hypothesis we studied: a) via FISH for CKS1B amplification in a cohort of patients treated at the Mayo Clinic with high dose chemotherapy and stem cell support, as well as a group of patients with cytogenetically defined hypodiploidy, and b) a cohort of myeloma patients that were studied by gene expression profiling. Gene expression analysis was performed on CD138-enriched plasma-cell RNA using Affymetrix U133A chips (Affymetrix, Santa Clara, CA). Results: Of 159 patients studied 46 exhibited FISH abnormalities consistent with increase number of signals for CKS1B (30%): amplification was marginal or low in 44 cases, and in only two cases the ratio between CKS1B and control probe was greater than 2.0. Therefore, the predominant pattern is one of gene duplication rather than amplification where gene copy usually exceeds 10 and ratio with control probe exceeds 5 (e.g. HER-2/neu amplification). Patients with CKS1B duplication had a higher prevalence of chromosome 13 deletion (72%), and t(4;14) (29%). The presence of CKS1B duplication was more frequent (53%) among 19 patients with hypodiploidy. Using gene expression data for CKS1B, we found a positive association with t(14;16)(q32;q23). The level of CKS1B gene expression positively correlated with the PCLI (p<0.0001) but there was heterogeneity in this relationship (r2 = 0.34). We found no correlation between the expression level of CKS1B and p27 (r2 = 0.008, p = 0.37). While CKS1B gene duplication had a negative effect on survival this effect was weak (29.9 versus 38 months, p = 0.124. Median follow-up is 55 months) and disappeared when the variable was entered into the multivariate model including PCLI, B2-microglobulin and all the major genetic abnormalities by FISH. Likewise the level of expression of CKS1B determined by gene expression only carried prognostic significance when extreme levels of expression were utilized as a prognostic variable. Discussion: In this study we show that increase copy number of CKS1B is present in one third of patients with MM (majority of these being gene duplication) and seem to be associated with a shorter overall survival, but the net effect of this is rather weak in our series. Further study is needed to understand its potential role as a progression factor in the plasma cell neoplasms.

Abstract H-MM affects about 40–50% of patients, and a similar proportion of MGUS/SMM. The genetic evolution of the disease and the clinical implications of the co-existence of 13q- or t(14q32) are unknown. We conducted a global survey of genetic abnormalities in H-MM in order to describe genetic evolution pathways. H-MM cases from the Mitelman cancer genetic database were combined with cases from the Mayo Clinic MM genetic database. All abnormalities (regional/whole chromosome gains/losses, breakpoints and translocations) were plotted against a 344-chromosome band profile created in a matrix format, and the number of genetic abnormalities per tumor (NAPT) logged. The abnormalities present in more than 5% of tumors were considered recurrent and each karyotype was scored for the presence or absence of each of the recurrent abnormalities. To investigate the temporal pattern of acquisition of genetic abnormalities, all tumors with a given abnormality were selected and the distributions of NAPT plotted. The modes of these distributions were used as a value of ‘lateness’, referred to as time of occurrence (TO). The impact of co-existence of 13q- and t(14q32) on progression free survival (PFS) and overall survival (OS) in H-MM was determined for MM patients entered into an Eastern Cooperative Oncology Group chemotherapy trial. Four hundred and sixty-nine H-MM patients were included in the karyotypic analysis. The median chromosome number was 53 (range 48–74) and the median NAPT was 10 (range 1–25). The distribution of NAPT revealed a normal distribution, suggesting an obligatory acquisition of a given number of genetic abnormalities. The most common abnormalities were trisomies of chromosomes 3,5,7,9,11,15,19 and 21 affecting a third or more of the patients. Deletions and abnormalities of even-numbered chromosomes occur in 20% or less of patients. None of the more than 300 specific translocations detected were recurrent. However, 5 translocation breakpoints were recurrent including 14q32, 8q24 and 11q13. TO analysis suggest that for H-MM, the trisomies are early genetic events, translocations occur midway and deletions tend to be later events. Amongst the trisomies, correlation analysis does not suggest a particular order of acquisition. Clustering analysis using principal component analysis suggests that in H-MM, IgH translocations are secondary events associated with disease evolution rather than defining unique biological entities. Consistent with this, survival of H-MM patients is not affected by 13q- status but is negatively impacted by the presence of t(14q32) especially those with unknown partners (p<0.05). The data presented suggest that H-MM fit a proposed aneuploid model of cancer due to auto-catalytic chromosome reassortment (Duesberg et al Cell Cycle2003:2:202–210). The presence of tumor specific trisomies and the apparent similar phenotype induced by various combinations of trisomies are consistent with this model.

Abstract Background: Abnormally increased tumor associated neovasculature plays an important role in tumor progression in solid tumors and hematological malignancies. In multiple myeloma (MM) bone marrow angiogenesis, measured in terms of microvessel density (MVD), has prognostic value, and appear to increase with disease progression from monoclonal gammopathy of undetermined significance to relapsed MM. We have shown that MVD has prognostic value in patients with newly diagnosed MM including patients undergoing upfront high dose therapy and stem cell transplantation, but comparison with other known prognostic factors has been limited by sample size. It is also not known whether the MVD adds prognostic value once the recently described International Staging System (ISS) is applied. The goal of this study was to determine the prognostic effect of bone marrow MVD in newly diagnosed MM relative to the ISS and other known prognostic factors. Methods: We studied 400 patients with newly diagnosed MM seen at the Mayo Clinic between March of 1988 and December 2001. Sections from bone marrow biopsy blocks from the time of initial diagnosis were studied by immunohistochemistry using antibodies against CD34 antigen to high light the endothelial cells. Under low power (100X); three areas with maximum number of microvessels (hotspots) were identified. Each of these areas was further studied at 400X magnification and the number of microvessels per high power field counted. The average of the three readings was taken as the MVD for the sample. In addition, the samples were graded as low, intermediate or high by using a visual estimate as previously described. Additional clinical data was extracted from medical records. Some of the patients have been included in previous studies related to angiogenesis. Results: A total of 400 patients in whom a bone marrow biopsy from within 30 days of diagnosis was available were studied. The pts were followed for a median of 37 months (Range: 1 month to 16.5 years) and 318 pts (80%) had died at the time of this analysis. The median MVD for the entire group was 14.7 (Range 0–168). The median overall survival for the three groups according to the MVD grade was lower for the high grade group (31.9 months) compared to the intermediate grade group (37.2 months) and the low grade group (not reached); P <0.029, log rank test. We examined this group of patients for other factors prognostic for overall survival. Factors significant on univariate analysis included ISS stage, platelet count (<150 vs. >= 150 X 106/L), and plasma cell labeling index (<1 vs >=1). In a multivariate analysis using these variables and MVD as a continuous variable, high MVD and the ISS staging system were significantly associated with poorer survival (Table). Conclusion: In this large group of pts with newly diagnosed MM, we confirm the prognostic value of increased bone marrow angiogenesis. We examined the MVD as a continuous variable in the multivariate analysis for a closer evaluation of this measure in this comparison. More importantly, the prognostic value appears to be independent of the ISS and other major prognostic factors. The resultsof this study reinforces the biological relevance of this finding in MM. HR 95% CI P value MVD 1.006 (1.001, 1.011) 0.0279 ISS Stage I 0.37 (0.25, 0.56) <0.001 ISS Stage II 0.58 (0.41, 0.83) 0.0025