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Purpose: Patients' concerns regarding clinical trial (CT) participation include apprehension about side effects, quality of life (QoL), financial burden, and quality of care., Methods: We prospectively evaluated the experience of patients with multiple myeloma or lymphoma who were treated on CTs (CT group, n = 35) versus patients treated with standard approaches (non-CT group, n = 88) focusing on QoL, financial burden of care, and patients' perception of quality of care over a 1-year period., Results: There were no significant differences in any of the patient-reported outcomes in CT versus non-CT groups. We observed an initial decline in overall QoL in the first 3 months across both groups, driven primarily by physical and functional well-being. QoL gradually improved and was above baseline by month 12. Patients reported highest improvement in the functional well-being subdomain. Patients in both groups reported high satisfaction with the quality of care received, and there were no differences in overall satisfaction, communication with team, or access to care. At baseline, 16%-19% of patients reported financial burden, which increased to a peak of 33% in the CT group and to 49% in the non-CT group over the course of 1 year. There was no significant difference in financial burden in the two groups overall. Most of the patients reported getting all the care that was deemed medically necessary in both groups. However, a significant proportion of patients reported having to make other kinds of financial sacrifices because of their cancer (CT group: 33% of patients at baseline and 21%-40% over 1 year; non-CT group: 19% at baseline and 25%-36% over 1 year)., Conclusion: Patients treated on CTs reported comparable QoL and quality of care with the non-CT group. A high proportion of patients reported financial burden over time in both groups. Our findings can serve as a guide to educate patients regarding CT participation and highlight the need to address the significant financial burden experienced by patients with cancer.

Citron Rho-interacting serine/threonine kinase (CIT) is a serine/threonine kinase that acts as a key component of the midbody and is essential for cytokinesis. CIT has been reported to be highly expressed in some tumor tissues and to play a role in cancer proliferation; however, the significance of CIT has not been investigated in multiple myeloma (MM). Here, we identified, by protein microarray and immunohistochemistry, that CIT is 1 of the upregulated proteins in the plasma cells of MM patients compared with healthy controls. Analysis of a gene expression profile data set showed that MM patients with high CIT gene expression had significantly worse overall survival compared with MM patients with low CIT gene expression. CIT silencing in MM cell lines induced cytokinesis failure and resulted in decreased MM cell proliferation in vitro and in vivo. TP53 expression was found to be an independent predictor of CIT dependency, with low-TP53 cell lines exhibiting a strong dependency on CIT. This study provides the rationale for CIT being a potential therapeutic target in MM in future trials., (© 2019 by The American Society of Hematology.)

This phase 1 study (clinical trial NCT00477815) was conducted to determine the maximum tolerated dose (MTD) of yttrium-90 ibritumomab tiuxetan ( 90 Y-Zevalin) with high dose melphalan (HDM) therapy in multiple myeloma (MM) patients undergoing autologous stem cell transplantation (ASCT). In a 3+3 trial design, 30 patients received rituximab 250 mg/m 2 with indium-111 ibritumomab tiuxetan ( 111 In-Zevalin) for dosimetry (day -22); rituximab 250 mg/m 2 with escalating doses of 90 Y-Zevalin (day -14); melphalan 100 mg/m 2 (days -2,-1) followed by ASCT (day 0) and sargramostim (GM-CSF, day 0) until neutrophil engraftment. Each patient's 111 In-Zevalin dosimetry data were used to calculate the dose of 90 Y-Zevalin (in mCi) to deliver 10, 12, 14, 16, 18 or 20 Gy to the liver. Dose limiting toxicities were seen in 3 patients. The overall response rate was 73% (22/30) with stringent complete response in 2 patients; complete response, 5; very good partial response, 12; and partial response, 3. The median PFS was 16.5 months and the median overall survival was 63.4 months. In MM, the MTD of 90 Y-Zevalin with HDM is 18 Gy to the liver. The addition of radiation with novel delivery methods such as radioimmunotherapy combined with standard transplant regimens warrants further study.

This phase 2 trial was designed to evaluate ixazomib, an orally bioavailable proteasome inhibitor, in patients with myeloma who have limited prior exposure to bortezomib. Thirty-three patients with relapsed multiple myeloma were enrolled. Ixazomib was given at 5.5 mg weekly for 3 of 4 weeks. Dexamethasone was added for lack of a minor response (MR) by end of cycle 2 or lack of a partial response (PR) by end of cycle 4 or for disease progression at any time. Median age was 69 years; patients had a median of two prior therapies (range 1-7). A grade 3 or 4 adverse event considered at least possibly related to drug was seen in 19 (59%) and 6 (19%) patients, respectively. The most common adverse events were thrombocytopenia, fatigue, nausea and diarrhea. Dexamethasone was initiated in 22 (67%) patients, 17 for not reaching the desired response and 5 for progression. Response (⩾PR) to single agent was seen in five patients within four cycles of therapy including three patients with PR, one patient with complete response (CR) and one patient with stringent CR. Six additional patients with either an MR (2) or SD (4) achieved a PR after addition of dexamethasone, translating to an overall response rate of 34%.

Smoldering multiple myeloma (SMM) carries a 50% risk of progression to multiple myeloma (MM) or related malignancy within the first 5 years following diagnosis. The goal of this study was to determine if high levels of circulating plasma cells (PCs) are predictive of SMM transformation within the first 2-3 years from diagnosis. Ninety-one patients diagnosed with SMM at Mayo Clinic from January 1994 through January 2007, who had testing for circulating PCs using an immunofluorescent assay and adequate follow-up to ascertain disease progression, were studied. High level of circulating PCs was defined as absolute peripheral blood PCs >5 × 10(6)/l and/or >5% PCs per 100 cytoplasmic immunoglobulin (Ig)-positive peripheral blood mononuclear cells. Patients with high circulating PCs (14 of 91 patients, 15%) were significantly more likely to progress to active disease within 2 years compared with patients without high circulating PCs, 71% versus 24%, respectively, P=0.001. Corresponding rates for progression within 3 years were 86% versus 34%, respectively, P<0.001. Overall survival (OS) after both SMM diagnosis and MM diagnosis was also significantly different. High levels of circulating PCs identify SMM patients with an elevated risk of progression within the first 2-3 years following diagnosis.

Patients with asymptomatic (smoldering) multiple myeloma (AMM) have a high risk of transformation to active multiple myeloma (MM). Bisphosphonates such as zoledronic acid (ZLD) reduce skeletal events in MM and the immunomodulatory agent thalidomide (Thal) has proven effectiveness in active MM. We hypothesized that treatment with Thal and ZLD would prolong the time to progression (TTP) to MM over ZLD alone. Eligible patients had asymptomatic MM and all patients received ZLD 4 mg intravenous monthly; the treatment arm also received Thal 200 mg per day. The TTP was superior for Thal/ZLD (n=35) patients compared with ZLD alone (n=33); median TTP of 2.4 years (95% confidence interval (CI): 1.4-3.6) versus 1.2 years (95% CI: 0.7-2.5) (hazard ratio (HR), 2.05; 95% CI: 1.1-3.8; P-value: 0.02). At 1 year, 86% of Thal/ZLD patients were progression free compared with 55% on ZLD alone (P=0.0048). The overall response rate after year 1 was 37% for Thal/ZLD with a median duration of response of 3.3 years (95% CI: 1.1-NA); there were no confirmed responses to ZLD alone (P=0.0004). The addition of Thal to standard ZLD produces anti-tumor responses whereas ZLD alone does not. Thal/ZLD also prolongs TTP from AMM to MM. This study provides the rationale for further studies in patients with AMM to delay chemotherapy.

Purpose: Oncolytic viruses are self-amplifying anticancer agents that make use of the natural ability of viruses to kill cells. Adenovirus serotype 5 (Ad5) has been extensively tested against solid cancers, but less so against B-cell cancers because these cells do not generally express the coxsackie and adenoviral receptor (CAR). To determine whether other adenoviruses might have better potency, we "mined" the adenovirus virome of 55 serotypes for viruses that could kill B-cell cancers., Experimental Design: Fifteen adenoviruses selected to represent Ad species B, C, D, E, and F were tested in vitro against cell lines and primary patient B-cell cancers for their ability to infect, replicate in, and kill these cells. Select viruses were also tested against B-cell cancer xenografts in immunodeficient mice., Results: Species D adenoviruses mediated most robust killing against a range of B-cell cancer cell lines, against primary patient marginal zone lymphoma cells, and against primary patient CD138+ myeloma cells in vitro. When injected into xenografts in vivo, single treatment with select species D viruses Ad26 and Ad45 delayed lymphoma growth., Conclusions: Relatively unstudied species D adenoviruses have a unique ability to infect and replicate in B-cell cancers as compared with other adenovirus species. These data suggest these viruses have unique biology in B cells and support translation of novel species D adenoviruses as oncolytics against B-cell cancers., (©2011 AACR)

Cast nephropathy is the most common cause of renal disease in multiple myeloma, however, treatment with plasma exchange remains controversial even after 3 randomized controlled studies. We sought to determine the importance of diagnostic confirmation and goal directed therapy in the treatment of cast nephropathy in forty patients with confirmed multiple myeloma and renal failure who underwent plasma exchange. A positive renal response was defined as a decrease by half in the presenting serum creatinine and dialysis independence. No baseline differences were noted between eventual renal responders and non-responders. Three quarters of the patients with biopsy proven cast nephropathy resolved their renal disease when the free light chains present in the serum were reduced by half or more but there was no significant response when the reduction was less. The median time to a response was about 2 months. In patients without cast nephropathy, renal recovery occurred despite reductions in free light chain levels of the serum. No association was found between free light chains in the serum, urinary monoclonal proteins, overall proteinuria and cast nephropathy. We found that the relationship between renal recovery and free light chain reduction was present only in patients with biopsy proven cast nephropathy showing the importance of extracorporeal light chain removal in this disease.

Clinical outcomes for multiple myeloma (MM) are highly heterogeneous and it is now clear that pivotal genetic events are the primary harbingers of such variation. These findings have broad implications for counseling, choice of therapy and the design and interpretation of clinical investigation. Indeed, as in acute leukemias and non-hodgkins lymphoma, we believe it is no longer acceptable to consider MM a single disease entity. As such, the accurate diagnosis of MM subtypes and the adoption of common criteria for the identification and stratification of MM patients has become critical. Herein, we provide a consensus high-risk definition and offer practical guidelines for the adoption of routine diagnostic testing. Although acknowledging that more refined classifications will continue to be developed, we propose that the definition of high-risk disease (any of the t(4;14), t(14;16), t(14;20), deletion 17q13, aneuploidy or deletion chromosome 13 by metaphase cytogenetics, or plasma cell labeling index >3.0) be adopted. This classification will identify most of the 25% of MM patients for whom current therapies are inadequate and for whom investigational regimens should be vigorously pursued. Conversely, the 75% of patients remaining have more favorable outcomes using existing - albeit non-curative - therapeutic options.

Background and Objectives: Bone marrow angiogenesis is increased in patients with multiple myeloma (MM) and correlates with disease stage., Design and Methods: Previous studies of quantifying vascular endothelial growth factor (VEGF) and VEGF receptors (VEGFR) in plasma cells from patients at different stages of MM found no significant difference in expression between overt MM and earlier pre-malignant stages of the disease namely, monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM)., Results: In this report we used quantitative flow cytometry to study cytoplasmic VEGF (cyVEGF) expression (measured as antibody binding capacity) in plasma cells from patients with MM (n = 22), MGUS/SMM (n = 12), and AL-amyloidosis (AL) (n = 9). CyVEGF expression was higher in MM (169,591) than in MGUS/SMM (144,858), or AL (106,011) although these differences were not statistically significant. Using an indirect VEGFR assay that measures VEGF binding, we found VEGF receptors on plasma cells from all groups of patients, with the lowest expression on plasma cells from normal individuals. We detected VEGF R1, VEGF R2, and VEGF R3 on plasma cells from all groups of patients and found receptor expression predominantly in the subset of CD45-positive plasma cells., Interpretation and Conclusions: This study supports the concept that VEGF is involved in the pathogenesis of MM, and suggests that VEGF may differentially affect a subset of plasma cells.

Multiple myeloma (MM) is characterized by accumulation of clonal plasma cells (PCs). CD45, a key regulator of antigen-mediated signaling and activation in lymphocytes, is present in early stages of PCs development. We studied CD45 expression on MM PCs by flow cytometry, correlating it to important biological disease characteristics. Additionally, we examined the expression of various adhesion molecules on PCs. A total of 75 patients with untreated MM (29), relapsed MM (17), smoldering MM (12), and monoclonal gammopathy of undetermined significance (MGUS) (17) were studied. The proportion of PCs expressing CD45 was higher among those with early disease (MGUS or smoldering MM) compared to those with advanced disease (new or relapsed MM) (43 vs 22%; P=0.005). Among those with advanced disease, patients with bone lesions had a lower percentage of CD45-positive (CD45+) PCs; 14 vs 34% (P=0.02). Patients with high-grade angiogenesis had a lower percentage of CD45+ PCs; 13 vs 31% (P=0.03). The median overall survival for the CD45+ group (>20% PCs positive) was 39 vs 18 months for the CD45-negative (CD45-) group (P=0.07). The expression of CD138, CD56 and CD54 were higher among the CD45- PCs. This study demonstrates important biological correlates of CD45 expression on myeloma cells., (Leukemia (2005) 19, 1466-1470.)

Despite response rates of 30% after high-dose chemotherapy with autologous hematopoietic stem cell transplant, patients with multiple myeloma are not cured. 153Samarium ethylenediaminetetramethylenephosphonate (153Sm-EDTMP; Quadramet) is a short-range, beta-emitting therapeutic radiopharmaceutical with avid skeletal uptake. In total, 12 patients were treated with escalating doses of 153Sm-EDTMP (N=3/group; 6, 12, 19.8, and 30 mCi/kg) and a fixed dose of melphalan (200 mg/m(2)). No dose limiting toxicity was seen. To better standardize the marrow compartment radiation dose, the study was modified such that an additional six patients were treated at a targeted absorbed radiation dose to the red marrow of 40 Gy based on a trace labeled infusion 1 week prior to the therapy. Despite rapid elimination of unbound radiopharmaceutical via kidneys and bladder, no episodes of nephrotoxicity, hemorrhagic cystitis, or delayed radiation nephritis were observed with a median follow-up of 31 months (range 8.5-44). Median times to ANC>0.5 and platelet >20 x 10(6)/l were 12 and 11 days, respectively, with no graft failures. Overall response rate was 94% including seven very good partial responses and five complete responses. Addition of 153Sm EDTMP to melphalan conditioning appears to be safe, well-tolerated and worthy of further study.

Given the survival advantage, high-dose therapy (HDT) remains the standard of care for patients with multiple myeloma eligible for the procedure. For those undergoing HDT, initial therapy aimed at reducing tumor burden is given prior to stem cell harvest. Various regimens, mostly variations of VAD (vincristine, doxorubicin, dexamethasone), are used for induction therapy. We retrospectively evaluated if single agent dexamethasone would be an effective induction therapy, given that it is the most active drug in these combinations. A total of 35 patients who received induction therapy with dexamethasone alone were compared to a similar group of 72 patients who received VAD as the initial therapy. We found a 63% response rate with dexamethasone compared to 74% with VAD (P=0.25). Including minimal responses, the overall response rate for Dex and VAD was 74 and 86%, respectively (P=0.13). The overall and complete response rates to transplant, respectively, were 97 and 26% for the dexamethasone group and 100 and 39% for the VAD group; P=0.33 and 0.18. No significant differences were observed in the progression-free and overall survival at 1 year post transplant. Single agent dexamethasone appears to be an effective alternative to VAD for induction therapy prior to HDT in myeloma.

Bone marrow (BM) angiogenesis is increased in multiple myeloma and is an important prognostic factor. However, prior studies were mainly done on patients receiving conventional chemotherapy and there is limited data on its prognostic value in patients undergoing high-dose therapy (HDT) as initial therapy. We studied BM angiogenesis in terms of microvessel density (MVD) in 88 newly diagnosed patients, who were uniformly treated, with 3-4 cycles of induction chemotherapy followed by HDT. We examined if MVD at diagnosis was predictive of response to induction therapy or to subsequent HDT. In addition, we also examined its prognostic value in these patients. The median MVD for primary refractory patients was 28 (range, 2-84) compared to 27 (range, 2-99) for responding patients (P=0.7). The median progression-free survival (PFS) was 21 months for those with high-grade angiogenesis compared to 42 months for those with low-grade angiogenesis, P=0.017. The median overall-survival (OS) from diagnosis was 40 months for those with high-grade angiogenesis and not yet reached, for those with low-grade angiogenesis, P=0.007. BM MVD at the time of initial diagnosis is an important prognostic factor for OS and PFS in patients undergoing autologous transplantation as frontline therapy for myeloma.

Autologous stem cell transplant (SCT) improves survival in multiple myeloma (MM) and remains the standard of care for eligible patients. Nearly a third of patients with newly diagnosed MM fail initial therapy aimed at reducing tumor burden preceding SCT (primary refractory). It is unclear if an initial response is important for successful SCT. We evaluated our experience with SCT in 50 patients with primary refractory MM and compared it to 101 patients with chemosensitive disease receiving SCT. The study cohort had a median age of 56 years (range 29-72) consisting of 87 males (58%). A total of 46 patients (92%) in the refractory group and 100 (99%) in the chemosensitive group had a response to transplant (50% or greater reduction in the M-protein). In all, 10 refractory patients (20%) and 35 (35%) in the chemosensitive group achieved a CR (P=0.06). The 1-year estimated progression-free survival from the time of transplant for the refractory group was 70% compared to 83% for the chemosensitive group (P=0.65). The lack of response to initial induction therapy does not appear to preclude a good response to SCT. We recommend that patients with primary refractory MM be offered early SCT.

Bone marrow (BM) angiogenesis is increased in multiple myeloma and is an important prognostic factor for survival. Previous studies have shown that BM angiogenesis does not change following chemotherapy or stem cell transplant. Given its potential antiangiogenic effect, we evaluated if thalidomide therapy would affect the BM microvessel density (MVD). We studied BM angiogenesis in 81 patients with various disease stages treated with thalidomide with or without dexamethasone. MVD was determined as previously described. MVD was compared between pretreatment marrows and those obtained 4-6 months following therapy. The median (range) MVD pretherapy was 28 (2-116) and post-therapy was 15 (3-97). A partial or complete response was seen in 58% of patients, stable disease in 41% and progressive disease in one patient. MVD decreased significantly in responders (median decrease of 12, P<0.001). In contrast, no significant change in MVD was seen in those failing to respond to thalidomide. Unlike the lack of resolution of angiogenesis reported with other therapies, we demonstrate for the first time a significant decrease in microvessels with thalidomide therapy. Although not conclusive, this result lends further support to the hypothesis that angiogenesis is a relevant therapeutic target in myeloma.

Angiogenesis or new vessel formation is an essential component in the growth and progression of neoplasms and there is growing evidence of its importance in hematological malignancies including multiple myeloma (MM). Vascular endothelial growth factor (VEGF) is believed to play a role in tumor angiogenesis. We studied the expression of VEGF and its receptors (VEGFR1 or Flt-1 and VEGFR2 or Flk-1/KDR) by myeloma cell lines and plasma cells isolated from patients, using different methods. VEGF expression by the plasma cells was demonstrated by immunohistochemistry in 18 of 20 patients with MM. Enzyme-linked immunosorbent assay demonstrated VEGF secretion in all six different myeloma cell lines studied. Five patient marrow samples and seven different myeloma cell lines were then studied for VEGF mRNA expression by reverse-transcriptase polymerase chain reaction (RT-PCR), which was positive in all. We further evaluated the expression of both VEGFR1 and VEGFR2 in different myeloma cell lines and five sorted myeloma bone marrow samples by RT-PCR. All the myeloma cell lines expressed VEGFR1 and three of the cell lines expressed VEGFR2. VEGFR1 expression was detected in all and VEGFR2 in all but one of the sorted marrow samples. Increased expression of VEGF by the myeloma cells taken in the context of the suspected prognostic value of marrow angiogenesis suggests a pathogenetic role for this cytokine and presence of its receptors on myeloma cells points toward an autocrine mechanism. Demonstration of the presence of VEGFR2 in our study provides a potential biological explanation for the preclinical activity observed with VEGFR2 inhibitors.

The purpose of this study was to determine the effect of thalidomide on stem cell collection and engraftment in patients with multiple myeloma. We performed a retrospective review of 67 patients newly diagnosed with multiple myeloma at Mayo Clinic and treated with a single regimen prior to stem cell transplantation between January of 2000 and September of 2001. Stem cells were collected from 24 patients who received thalidomide, 200 mg/day, with dexamethasone as initial therapy before stem cell collection. These patients were compared with 43 control patients seen during the same period who had received only one previous regimen before stem cell collection and transplantation. The cumulative thalidomide dose before stem cell collection was 17 000 mg over a median of four cycles (range, 2-7 cycles). The thalidomide and control groups were not significantly different in their baseline characteristics, number of stem cells collected, time to collection, or time to engraftment of neutrophils or platelet count of 50 000/microl. Time to platelet count of 20 000/microl was delayed by a median of 4 days (P=0.008), but platelet transfusion requirements did not differ (P=0.95). We concluded that thalidomide does not substantially affect peripheral cell mobilization or engraftment.

Patients with early-stage myeloma are typically observed without therapy until symptomatic disease occurs. However, they are at high risk of progression to symptomatic myeloma, with a median time to progression of approximately 1-2 years. We report the final results of a phase II trial of thalidomide as initial therapy for early-stage multiple myeloma in an attempt to delay progression to symptomatic disease. In total, 31 patients with smoldering or indolent multiple myeloma were studied at the Mayo Clinic. Two patients were deemed ineligible because they were found to have received prior therapy for myeloma, and were excluded from analyses except for toxicity. Thalidomide was initiated at a starting dose of 200 mg/day. Patients were followed-up monthly for the first 6 months and every 3 months thereafter. Of the 29 eligible patients, 10 (34%) had a partial response to therapy with at least 50% or greater reduction in serum and urine monoclonal (M) protein. When minor responses (25-49% decrease in M protein) were included, the response rate was 66%. Three patients had progressive disease while on therapy. Kaplan-Meier estimates of progression-free survival are 80% at 1 year and 63% at 2 years. Major grade 3-4 toxicities included two patients with somnolence and one patient each with neuropathy, deep-vein thrombosis, hearing loss, weakness, sinus bradycardia, and edema. Thalidomide has significant activity in early-stage myeloma and has the potential to delay progression to symptomatic disease. This approach must be further tested in randomized trials.

The nonrandom recurrent nature of chromosome abnormalities in myeloma suggests a role for them in disease pathogenesis. We performed a careful cytogenetic analysis of patients with abnormal karyotypes (n = 254), to discern patterns of association, search for novel abnormalities and elucidate clinical implications. Patients with karyotypic abnormalities suggestive of myelodysplasia/acute leukemia were excluded. In this study we compared survival by abnormality only between patients with abnormal karyotypes. Patients with abnormalities were more likely to have features of aggressive disease as compared to all other patients without abnormalities entered into the myeloma database (lower hemoglobin, higher beta(2)-microglobulin, labeling-index and plasmocytosis; all P < 0.0001). Several groups of patients could be readily identified; hypodiploid (22%), pseudodiploid (36%), hyperdiploid (31%) and near-tetraploid (11%). Clustering associations were seen among several trisomies and monosomy of chromosome 13 and 14. Several monosomies (-2, -3, -13, -14 and -19), 1p translocations/ deletions, and hypodiploidy were associated with a significantly shorter survival. Trisomy of chromosome 13 was rare ( <2%). Even among patients with abnormal karyotypes, specific chromosome abnormalities can impart biologic variability in myeloma, including several monosomies, hypodiploidy and abnormalities of 1p.

Interleukin 6 (IL-6) is known to play an important role in the biology of the malignant plasma cells in multiple myeloma. In an effort to better understand IL-6 stimulated myeloma cell growth, we have performed gene expression profiling to identify IL-6 early response genes. Using the KAS-6/1 IL-6-dependent human myeloma cell line, IL-6 stimulation dramatically induced expression of monocyte chemoattractant protein-1 (MCP-1) mRNA. To verify this result, we used reverse transcriptase PCR and RNAse protection assays and demonstrated using both assays that MCP-1 is indeed an IL-6 responsive gene in a variety of IL-6-responsive myeloma cell lines. Moreover, we also demonstrated IL-6 stimulated MCP-1 secretion by the myeloma cell lines as well as by fresh patient tumor cells. Lastly, we present evidence that fresh patient tumor cells express mRNA for the MCP-1 receptor, CCR2, as do myeloma cell lines along with a second MCP-1 receptor, CCR11. Although MM cell chemotaxis in response to MCP-1 was only minimal, we were able to demonstrate that MCP-1 stimulated activation of MAPK. Because of the important role that this chemokine plays in both angiogenesis and bone homeostasis, and the ability of MCP-1 to activate myeloma cells, these results suggest a new mechanism by which IL-6 may contribute to disease pathogenesis.

In myeloma, the bone marrow plasma cell percentage (BMPC%) is usually estimated independently on the aspirate, core biopsy, and plasma cell labeling index (PCLI) samples. This study was done to determine which of the 3 individual estimates correlates best with complete response (CR) and survival. Seventy-five consecutive patients who underwent SCT for relapsed myeloma were studied. The median BMPC% on the marrow aspirate, core biopsy, and PCLI studies were 20, 25, and 20, respectively. There was a significant correlation between the three methods, rho > 0.65, P < 0.001. However, in 8% of patients the BMPC% was different by an absolute value of 50% between methods. No individual method was predictive for CR. However, the highest estimate of the BMPC% among the three methods was a significant predictor of CR (P = 0.02). Survival following SCT was longer among patients with a low BMPC% (< or =60) by the PCLI method compared to those with higher values, median survival 23 versus 7 months, respectively, P = 0.02. PFS was also different, with survival times of 11 and 5 months, respectively, P = 0.003. Similar results were obtained when the highest estimate of the BMPC% was used in survival analysis (P = 0.02 and 0.004, respectively). Statistical significance was lower when the BMPC% on the aspirate or biopsy used in survival analysis. Compared to any individual method of estimating BMPC%, the highest estimate of the BMPC% is the best predictor of CR in myeloma. It is also prognostic for poor survival and PFS following SCT for myeloma. We recommend that all three methods of estimating BMPC% be routinely performed and that the highest value be used for prognostic purposes., (Copyright 2001 Wiley-Liss, Inc.)

We conducted a clinical trial of thalidomide as initial therapy for asymptomatic smoldering (SMM) or indolent multiple myeloma (IMM). Sixteen patients were studied. Thalidomide was given orally at a dose of 200 mg/day for 2 weeks, and then increased as tolerated by 200 mg/day every 2 weeks to a maximum dose of 800 mg/day. Bone marrow microvessel density (MVD) and angiogenesis grading were estimated using CD34 immunostaining. Six patients had a confirmed response to therapy with at least 50% or greater reduction in serum and urine monoclonal (M) protein. When minor responses (25-49%) decrease in M protein concentration) were included, 11 of 16 patients (69%) responded to therapy. Major grade 3-4 toxicities included two patients with somnolence, and one patient each with syncope and neutropenia. Pre-treatment MVD was not a significant predictor of response to therapy, median MVD 4 and 12 in responders and non-responders respectively, P = 0.09. We conclude that thalidomide has significant activity in the treatment of newly diagnosed SMM/IMM. However, we do not recommend treatment with thalidomide at this stage since some patients with SMM/IMM can be stable for several months or years without any therapy. Additional randomized trials are needed to determine if thalidomide will delay progression to active multiple myeloma.

The plasma cell labeling index (PCLI) is a measure of plasma cell proliferative activity and is an important prognostic factor in newly diagnosed multiple myeloma (MM). Occasionally patients have been observed with stable, plateau phase MM with minimal numbers of residual light-chain-restricted monoclonal plasma cells, but a high PCLI. No data are available on the outcomes for such patients. Data from 57 patients with plateau phase MM and a marrow PCLI of more than 1.0% were compared with 105 matched control patients with MM with a marrow PCLI of less than 1.0%. All patients had less than 10% total plasma cells on marrow aspirate and biopsy. The median time to progression and overall survival were 8 months and 20 months, respectively, in the high PCLI group versus 39 months and 56 months, respectively, in the low PCLI group (P < .0001). These findings suggest that a high PCLI in patients with apparently stable, plateau phase MM is an adverse parameter that may predict a short time to disease progression and death.

We studied the effect of complete response (CR) among 126 consecutive patients who underwent stem cell transplantation (SCT) for myeloma. The CR rate with SCT was 33%. Median overall survival (OS) from diagnosis of myeloma was 56 months. OS following SCT was 22 months. Progression-free survival (PFS) was 12 months. OS was not different between patients who achieved CR and those who did not, median survival 25 vs 24 months, P = 0.5. Corresponding median times for PFS were 15 and 11 months, P = 0.2. The plasma cell labeling index (PCLI) was high (> or = 1%) in 36% (high risk group) and was associated with poor OS and PFS (P < 0.001). Achieving CR did not influence OS or PFS in either the high or the low risk group. In contrast, OS and PFS were significantly influenced by high PCLI both in patients who achieved CR and those who did not. OS was poor (< 30 months) in high risk patients regardless of CR status and in low risk patients who did not achieve CR, compared to low risk patients achieving CR (57 months), making them candidates for novel post-transplant treatment options. Outcome following SCT is dependent more on biological variables such as the PCLI than on CR status.

Angiogenesis is the formation of new blood vessels and occurs physiologically during embryonal growth, wound healing and during the menstrual cycle. It is essential for the proliferation and metastases of most malignant neoplasms. Recent evidence suggests that angiogenesis is increased in multiple myeloma and has prognostic value in the disease. Angiogenic cytokines such as vascular endothelial growth factor (VEGF) and basic fibroblast growth factor are expressed by myeloma cells and appear to play a role in the increased angiogenesis seen in myeloma. In addition, VEGF may serve as a paracrine growth factor for myeloma cells. Based on the increased angiogenesis observed in myeloma, thalidomide has been studied as antiangiogenic therapy. Although its mechanism of action in myeloma is still unclear, thalidomide appears to be active in 25-30% of patients with refractory myeloma. Major toxicities include constipation, sedation, skin rash, fatigue, and peripheral neuropathy. Studies are ongoing to determine its role as initial treatment for myeloma. This paper reviews the available data on angiogenesis in myeloma, and summarizes the role of thalidomide therapy in this disease. The pharmacology and toxicity of thalidomide are also discussed., (Copyright 2000 Harcourt Publishers Ltd.)

Objective: To describe the efficacy of therapy with thalidomide, a drug that has antiangiogenic properties, in patients with relapsed multiple myeloma., Patients and Methods: We studied 16 patients (median age, 64 years) who received thalidomide for relapsed myeloma at the Mayo Clinic in Rochester, Minn, between November 1998 and August 1999. Treatment consisted of thalidomide given orally at a dose of 200 mg/d for 2 weeks, then increased by 200 mg/d every 2 weeks, up to a maximal dose of 800 mg/d., Results: The stage of myeloma at treatment was Durie-Salmon IIIA in 9 patients (56%) and IIIB in 7 (44%). The median time from myeloma diagnosis to initiation of thalidomide therapy was 32 months. In 4 patients (25%) prior stem cell transplantation had failed, and 14 (88%) had received 2 or more prior chemotherapeutic regimens before institution of thalidomide. All patients were evaluable for response. Four (25%) achieved a partial response to therapy, with a greater than 50% reduction in the serum or urine M protein level. Responses lasted 2, 4+, 8, and 10+ months. Major adverse effects included constipation, sedation, rash, and peripheral neuropathy., Conclusion: Thalidomide is an active agent in the treatment of patients with advanced myeloma.

We studied the prognostic value of angiogenesis grading and microvessel density estimation in newly diagnosed multiple myeloma. Seventy-five patients with newly diagnosed myeloma, treated on Eastern Cooperative Oncology Protocol E9486 and Intergroup study 0141 (S9321) at the Mayo Clinic, were studied. Bone marrow microvessels were examined using immunohistochemical staining for von Willebrand factor. Determination of microvessel density and angiogenesis grading was done in a blinded manner. There was a strong correlation between microvessel density and the plasma cell labeling index, rho 0.42, P < 0.001. Angiogenesis grade was also significantly associated with the plasma cell labeling index. Fifteen % of patients with low-grade angiogenesis had a high labeling index (>1%). In contrast, 47% of patients with intermediate or high-grade angiogenesis had high labeling indices (P = 0.02). Overall survival was significantly different among those with high-, intermediate-, and low-grade angiogenesis, with median times of 2, 4, and 4.4 years, respectively (P = 0.02). Similarly, patients with microvessel density >50/x400 field had poorer survival compared with those with 50 or fewer microvessels/field, median survival 2.6 versus 5.1 years, respectively (P = 0.004). There was a strong association between angiogenesis grade and microvessel density (P < 0.001). We conclude that bone marrow angiogenesis is a predictor of poor survival in newly diagnosed myeloma. Angiogenesis is correlated with the plasma cell labeling index but not the bone marrow plasma cell percentage. A simple visual grading of angiogenesis is an efficient alternative to microvessel density estimation.

Malignant plasma cells can be detected in the blood of patients with multiple myeloma (MM) using flow cytometry (FC), immunofluorescence microscopy (IM), or a variety of molecular techniques. Increased numbers of light chain-restricted blood plasma cells as detected by IM is associated with a diagnosis of overt MM and a decreased overall survival. The IM technique is time consuming; therefore, a prospective study was designed to test whether CD38 CD45 FC could simplify the procedure. Blood samples from 769 patients with plasma cell proliferative disorders were studied prospectively by FC and IM over a one-year period. The FC technique was performed on 1 ml of whole blood after ammonium chloride red blood cell lysis and utilized anti-CD38PE and anti-CD45PerCP. The number of CD38+ 45- events were enumerated and compared to the number of light chain-restricted plasma cells detected by the standard IM technique. In 46% (353/769) of cases > or = 1 CD38+ CD45- events were detected by FC whereas IM was positive for light chain restricted plasma cells in 33%; there was concordance between FC and IM in 73% of cases. In 20% of cases FC was positive and IM was negative; however, in 7% of cases FC was negative yet light chain-restricted plasma cells were detected by IM. FC was positive in 88% (134/153) of cases where the IM technique showed a high number of circulating plasma cells. This study demonstrates that two-color CD38/45 FC identifies most cases with a high IM result and reduces the workload in the clinical laboratory. The prognostic implications of a positive FC screen but a negative IM will require long-term patient follow-up.

The optimal timing of stem cell transplantation for multiple myeloma is controversial. Late stem cell collection is undesirable because of the inability to mobilize stem cells. We report on 64 recipients of stem cells collected within 1 year after diagnosis, none of whom had transplantation in plateau phase of their disease. Patients seen within 12 months after diagnosis received four cycles of standard vincristine, doxorubicin, and dexamethasone (VAD) chemotherapy and then had stem cells mobilized. Patients were then placed on maintenance vincristine, BCNU, melphalan, cyclophosphamide, and prednisone or melphalan and prednisone chemotherapy for 12 cycles. At the sign of first progression, transplantation occurred. Fourteen patients were refractory to VAD chemotherapy, 20 relapsed on maintenance chemotherapy, and 30 relapsed off chemotherapy. The time to platelet engraftment was not affected by the duration of stem cell cryopreservation or extent of chemotherapy exposure after mobilization. The complete response rate was 34%. The actuarial median survival from initial diagnosis, from transplant day 0, and post-transplant progression-free survival was 51, 20 and 11.4 months, respectively. The patient status at transplantation and percentage of plasma cells circulating in the blood at apheresis influenced post-transplant survival; circulating plasma cells, status at transplantation and plasma cell labeling index influenced progression-free survival. Response duration was shorter in patients relapsing on chemotherapy.

There is now an improved understanding of the types of adhesion receptors present on normal and malignant plasma cells. This knowledge has been helpful in identifying plasma cells and in beginning to understand the pathogenesis of myeloma. Future research is needed to delineate the signaling pathways used by the plasma cell after the adhesion receptor binds to its ligands. This information should help in designing more effective therapy for this fatal disease.

The most common chromosomal translocation in multiple myeloma (MM) is t(11;14)(q13;q32). Here, we describe the clinical characteristics of patients with MM who have this translocation. We have identified 24 patients at our institution who had t(11;14)(q13;q32) as determined by standard cytogenetic analysis (CC). Seven patients had the translocation detected at the time of original diagnosis and 17 at the time of relapse. Median survival in all patients after original diagnosis was 43 months; median survival after the translocation was detected was 11.9 months. Four patients had a clinical diagnosis of plasma cell leukemia. Most patients had an elevated beta2-microglobulin (13/20 had >4 microg/ml). The bone marrow (BM) labeling index (LI) of patients, at the time of translocation detection, was elevated in most (median 1.4%, 17/23 patients had BMLI > or = 1%). Of the 24 patients, 19 (79%) died of disease progression and 5 (21%) were alive with disease at last follow-up. Lytic lesions, bone pain, or compression fractures eventually developed in all patients. Patients with MM who have t(11;14)(q13;q32) detected by standard cytogenetics seem to have an aggressive clinical course.

We compared the prognostic value of conventional cytogenetic analysis and established factors such as beta2-microglobulin and plasma cell labeling index in 70 patients undergoing autologous blood cell transplantation for multiple myeloma. Patients underwent transplantation 5 to 88 months (median, 20 months) after the initial diagnosis of myeloma. Factors studied were age, sex, beta2-microglobulin, response to prior therapy, plasma cell labeling index, cytogenetic analysis, bone marrow plasma cell percentage, lactate dehydrogenase and C-reactive protein. Twenty-eight of 65 patients (43%) had abnormal marrow cytogenetics. Overall survival measured from transplantation was significantly better in patients with normal cytogenetics than in those with abnormal cytogenetics (median survival, 25 vs 12 months, P = 0.003). Progression-free survival was better, with median times of 12 vs7 months, respectively (P = 0.005); overall survival measured from the time myeloma was first diagnosed was also longer, with median survivals of 62 and 39 months, respectively (P = 0.001). Median plasma cell labeling index was 1.5% in patients with abnormal cytogenetics and 0. 2% in those with normal cytogenetics (P < 0.001). Abnormal bone marrow cytogenetics predict poor survival after blood cell transplantation for myeloma. There is a significant correlation between abnormal cytogenetics and high plasma cell labeling index, suggesting that certain cytogenetic abnormalities may offer a proliferative advantage to myeloma cells.

We studied the prognostic value of clinical and laboratory variables, measured before blood cell transplantation, in predicting complete response among patients undergoing autologous blood cell transplantation for relapsed or primary refractory myeloma. Sixty-seven patients who underwent transplantation for relapsed or primary refractory myeloma were studied. The overall response rate was 90%, and the complete response rate was 33%. Low beta2-microglobulin (< or =2.7 mg/l) was associated with a significantly better complete response rate compared with high levels (54 vs 19%, P = 0.002). Similarly, the complete response rate was 39% when the bone marrow plasma cell percentage was low (<40%) and 21% with greater involvement (P = 0.04). Complete response rate was 50% when beta2-microglobulin and bone marrow plasma cell percentage were low, 36% if either was high, and 12% when both were high (P = 0.01). Median survival measured from initial diagnosis of myeloma was 51 months. Overall survival after transplantation was better among responders who achieved complete response than those who did not: median survival, 24 vs 11 months, P = 0.04 (log-rank) and 0.009 (Gehan-Wilcoxon). Attainment of a complete response independently predicted better survival in a multivariate analysis. beta2-Microglobulin and bone marrow plasma cell percentage predict complete responders among patients undergoing transplantation for myeloma.

The aim of this study was to evaluate the effectiveness of autologous stem cell transplantation for patients with relapsed or primary chemotherapy-refractory myeloma. Seventy-five patients, 50 men and 25 women, ages 33-68 years (median, 53 years), who underwent transplantation for relapsed or primary refractory myeloma were studied. Patients underwent transplantation 5-88 months (median, 23 months) after diagnosis of myeloma. The time to transplantation was significantly shorter in patients with refractory disease than for those with relapsed myeloma (median, 8 and 32 months, respectively; P < 0.001). Patients with primary refractory myeloma had a significantly lower plasma cell labeling index than those with relapsed disease (P = 0.008). There were no differences in overall and complete response rates between patients with primary refractory and relapsed disease. The median survival of the entire cohort from diagnosis was 53 months. Overall survival from transplantation among patients with relapsed myeloma receiving therapy, relapsed myeloma off therapy, and primary refractory myeloma was significantly different (P = 0.04), with median times of 12, 21 and 30 months, respectively. Progression-free survival also was different (P < 0.001), with median times of 7, 13, and 26 months, respectively. We conclude that overall and progression-free survival in patients with primary refractory myeloma appear better than in patients with relapsed disease and need further study.

Purpose: To study the prognostic value of plasmablastic morphology after autologous stem-cell transplantation for relapsed or primary refractory myeloma., Patients and Methods: Seventy-five patients were studied. Investigators blinded to the clinical details of the individual cases reviewed bone marrow aspirate slides to determine plasmablastic classification. Plasmablasts were defined using strict, well-described criteria. Plasmablastic morphology was considered to be present (plasmablastic myeloma) when 2% or more plasmablasts were present in the plasma-cell population., Results: Patients underwent transplantation 5 to 88 months (median, 20 months) after the initial diagnosis of myeloma. Twenty-eight percent of patients had plasmablostic morphology. A significantly greater proportion of patients with plasmablastic morphology had abnormal cytogenetics compared with those with nonplasmablastic classification (73% v 31%, respectively; P = .003). The overall survival rate measured from the time of transplantation was significantly worse in patients with plasmablastic morphology compared with those without (median survival time, 5 months v 24 months, respectively; P < .001). Progression-free survival time was shortened also, with a median time of 4 months compared with 12 months, respectively (P < .001). In the multivariate analysis, plasmablastic classification was the most powerful prognostic factor after transplantation for both overall (P = .001) and progression-free survival rates (P < .001). We also identified three risk groups based on plasmablastic morphology: plasma-cell labeling index, lactate dehydrogenase, and cytogenetics. The median overall survival time was 38 months when none of these factors was abnormal, 17 months with one abnormal factor, and 8 months with two or more abnormal factors (P < .001)., Conclusion: Plasmablastic morphology is a powerful independent predictor of poor survival rate after autologous stem-cell transplantation for relapsed or primary refractory myeloma.

Although most of the initial studies in angiogenesis were done on solid tumors, there is now data suggesting the importance of angiogenesis in hematologic malignancies. We estimated bone marrow microvessel density before autologous stem cell transplantation and at the time of response in 13 patients with myeloma (seven complete and six partial responders) using an immunohistochemical stain for factor VIII-related antigen (von Willebrand factor). Baseline microvessel density was significantly different between bone marrow samples from patients with myeloma and morphologically normal, staging marrows from patients with limited stage Hodgkin's disease, mean (+/- s.d.) 294 (+/-115)/mm2 vs 93 (+/-26/mm2, respectively, P = 0.001. After transplantation, microvessel density continued to be high in myeloma samples compared to samples from control patients with limited stage Hodgkin's disease, mean (+/- s.d.) 230 (+/-68)/mm2, P = 0.003. There was no difference in microvessel density at the time of complete or partial response compared to values prior to transplantation. This report confirms that increased angiogenesis is found in myeloma bone marrow prior to transplantation, and suggests that increased angiogenesis persists even after complete response.

Transplantation after high-dose chemotherapy prolongs survival in patients with multiple myeloma compared with standard therapy. It is unclear whether the optimal timing of transplantation is immediately after induction chemotherapy or whether stem cells may be cryopreserved for transplantation at subsequent progression or relapse. In this study, stem cells were collected within 6 months of diagnosis, followed by transplantation only at progression of myeloma. One hundred and eighteen patients with multiple myeloma had stem cells collected and cryopreserved. Eleven had transplants early in the disease after they demonstrated failure to respond to primary therapy. The remaining 107 were eligible for transplants when there was evidence of progressive disease. Of the 118 patients, 67 had transplants, nine died of progressive disease before transplantation, and 42 remain alive in plateau phase. The median survival of the group is 58.5 months; 67 are alive. Serum beta2-microglobulin, bone marrow labeling index (S phase), and hemoglobin level predicted overall survival (P < 0.006, P < 0.001, and P < 0.01, respectively). We conclude that early cryopreservation of blood stem cells followed by transplantation at progression is a feasible approach to therapy in patients with myeloma. The underlying biology of the disease has a greater impact on survival than the timing of transplantation. A prospective randomized trial is required to answer definitively the question of the optimal timing of blood cell transplantation.

Syndecan-1 is a low-affinity receptor for basic fibroblast growth factor (bFGF). In this study, we used flow cytometry to examine expression of syndecan-1 on monoclonal cells from the blood (n = 37) and marrow (n = 81) of patients with plasma cell (PC) proliferative disorders (PCPD) and blood cells from patients (n = 39) with B cell chronic lymphocytic leukemia (B-CLL). The marrow CD38+CD45- and CD38+CD45+ PC were syndecan-1 positive in all patients with PCPD and there was no difference between patients with monoclonal gammopathy of undetermined significance (MGUS) vs multiple myeloma or cases with vs without bone lesions. In 38% of cases, syndecan-1 expression on the PC was heterogeneous with > or =25% of PC syndecan-1 negative. We found similar syndecan-1 expression on blood and marrow PC in the 36 cases with paired samples. CLL cells were syndecan-1 negative in 97% (38/39) of the cases. Syndecan-1 is a useful marker to detect malignant plasma cells in the blood or marrow; however, it is not helpful in distinguishing MGUS from active myeloma. In addition, syndecan-1 is present on the less mature (CD45+) PC, and there is heterogeneity of expression within and between patients. The relevance of the bFGF bound to myeloma cells via syndecan-1 remains to be elucidated.

To investigate the pathophysiology of anemia, a two-color flow cytometric method was developed that measures the proliferative rate of the marrow erythroid cells (EPR). The method uses a monoclonal antibody, RC17.2, to identify erythroid precursors and propidium iodide to determine the %S-phase. This technique was then used to test the hypothesis that a decrease in the proliferative rate of the marrow erythroid precursors contributes to the anemia of multiple myeloma. The EPR was determined on the marrow aspirate from 56 patients and the mean EPR was 31.2% (median, 31: range, 14-55). Patients with anemia (n = 36) had a median EPR of 27% compared to 35% for those patients with a normal Hgb (p = < 0.001); however, there was no difference in the % marrow erythroid precursors (p = 0.96) or % marrow plasma cells (p = 0.08) between the two groups. These results suggest that one possible cause for the anemia of myeloma is a decrease in the EPR. This flow cytometric technique may also be useful in studying other anemias.

Complex cytogenetic abnormalities have been described in patients with multiple myeloma (MM). To better understand the significance of the most frequent translocation observed in MM, we studied the clinical characteristics of patients with MM and the t(11;14)(q13;q32) abnormality. A search of the cytogenetic database at the Mayo Clinic identified patients with MM and t(11;14)(q13;q32). The medical records were reviewed for the clinical characteristics of these patients. We identified 13 patients with MM and t(11;14)(q13;q32) determined by standard cytogenetic analysis: in 10 patients the abnormality was detected at the time of relapse (three with previously normal results of cytogenetic examination). At the time the translocation was detected, plasma cell (PC) leukaemia was clinically diagnosed in two patients. The median number of circulating PCs, as determined by the cytoplasmic immunofluorescence of T-cell-depleted peripheral blood mononuclear cells, was 1.1x10(9)/l (mean 1.74; range 0.0017-6.26x10(9)/l). On linear regression analysis there was a strong correlation between the number of circulating PCs and the number of bone marrow PCs. The median survival after demonstration of the translocation was 8.1 months. Of all patients, 10 died of disease progression and three were alive. Patients with MM who have t(11;14)(q13;q32) seem to have an aggressive clinical course, even when the abnormality is detected at the time of diagnosis, with evidence of many circulating PCs.

Insulin-like growth factors (IGF-I, IGF-II) have long been recognized as important mitogens in many types of malignancies. Because the role of IGFs in growth control of myeloma cells has not been extensively examined, we have used a panel of IL-6-responsive myeloma cell lines to address this issue. Initial studies demonstrated that IGF-I and IGF-II significantly enhanced DNA synthesis by each of the four cell lines, even when assayed in the absence of IL-6. The specificity of the IGF response was confirmed using an IGF-I receptor Ab, and additional studies demonstrated that IGF responsiveness did not result from induction of autocrine IL-6 expression. When IL-6 responsiveness was assayed, three of four cell lines synthesized DNA in response to IL-6 alone; however, the magnitude of responsiveness was greatly enhanced by addition of IGFs. Similar results were obtained when proliferation and cell cycle progression were analyzed. By contrast, the KP-6 cell line was responsive to IL-6 only when IGF was present. Finally, we analyzed the effects of IGF-I on normal B lymphocytes. IGF, however, did not stimulate B cell DNA synthesis, suggesting that IGF responsiveness may represent a key difference between normal and malignant B cells. In summary, these studies suggest that IGFs may play an important role in multiple myeloma by virtue of their ability to directly stimulate tumor cell growth as well as modulate the magnitude of IL-6-driven growth.

Monoclonal plasma cells (CD38+CD45-/dim) are typically present in the blood of patients with active myeloma and can contaminate stem cell harvests. This has led to strategies that select CD34+ cells for use in autologous stem cell transplantation with the goal of decreasing tumor cell contamination. The aim of this study was to learn if the CD34 antigen is expressed on monoclonal plasma cells in the blood or marrow of patients with multiple myeloma. We used three-color flow cytometry (surface CD38;CD45 and cytoplasmic kappa or lambda) to identify monoclonal plasma cells in the blood (n = 24) and marrow (n = 37) from patients with plasma cell proliferative disorders. In each case the CD38+CD45- and CD38+CD45dim+ monoclonal populations were then analyzed for CD34 expression. In all 24 blood and 37 marrow samples, the CD38+CD45-monoclonal plasma cells were negative for CD34 expression. CD38+CD45dim+ monoclonal cells were documented in the blood of 11 patients and in the marrow of 33 patients and this cell population was also CD34-negative in all cases. These results indicate that CD34 is usually not expressed on the CD38+CD45-CD45dim+ monoclonal plasma cells in the blood or marrow of patients with plasma cell proliferative disorders. CD34 selection methods should therefore decrease the chance of tumor cell contamination of the stem cell product.

We sought to determine whether circulating tumor cells in the blood stem cell harvest from patients with multiple myeloma are associated with a shortened disease-free survival. Prospective analysis was performed in 33 patients of blood obtained at leukapheresis for future transplantation. An immunofluorescence microscopy procedure identified the tumor cells by their morphology and monotypic light chain staining. Eighteen patients had increased (> or = 0.2 x 10(6)/l) monoclonal plasma cells circulating in the blood at stem cell harvest. Fifteen of the 18 have relapsed, with a median relapse-free survival of 6.2 months. Of 15 patients with < 0.2 x 10(6) cells/l, seven have relapsed, with a median relapse-free survival of 22.5 months (P = 0.008). Patients with circulating plasma cells showed a trend toward shorter overall survival (P = 0.078). In a multivariate analysis using the bone marrow plasma cell labeling index and beta 2-microglobulin, the absolute number of plasma cells in the stem cell harvest achieved borderline significance for predicting relapse-free survival (P = 0.057). In conclusion, increased monoclonal plasma cells in the blood stem cell harvest are associated with a shortened relapse-free survival. This does not necessarily indicate that the circulating plasma cells were responsible for relapse. These results, however, have implications with regard to the timing of obtaining blood stem cells for patients who are candidates for ablative chemotherapy.

The purpose of this study was to quantitate the number and labeling index of monoclonal plasma cells in the blood of patients with newly diagnosed multiple myeloma (MM) to learn if these values were independent prognostic factors for survival. Patients were candidates for this study if they had untreated myeloma requiring therapy, were evaluated at our institution between 1984 and 1993, and had a sample of blood analyzed with a sensitive immunofluorescence technique for monoclonal plasma cells and the blood B-cell labelling index (BLI). The % blood monoclonal plasma cells (%BPC) and the BLI were analyzed along with stage, marrow plasma cell LI, % marrow plasma cells, calcium, creatinine, albumin, beta-2-microglobulin, and C-reactive protein as univariate and multivariate factors for survival. Eighty percent of the 254 patients accrued to this study had monoclonal BPC detected. The median % BPC was 6% and 57% (144 of 254) of patients had a high number (> or = 4%). Patients with > or = 4% BPC had a median survival of 2.4 years vs 4.4 years for those with < 4% BPC (P < .001). The BLI was also prognostic (P = .008). In a multivariate analysis, the % BPC, age, albumin, stage, marrow plasma cell LI, and the BLI were independent factors for survival. The %BPC and the marrow plasma cell LI best separated the group into low, intermediate, and high risk myeloma with median survivals of 52, 35, and 26 months, respectively. Patients with high %BPC were less likely to have lytic bone disease from their MM (P = .002). The %BPC and the BLI are independent prognostic factors for survival and are useful in identifying patients as low, intermediate, and high risk. Clonal cells in the blood should be quantified in future clinical trials for myeloma.

The blood of most patients with active multiple myeloma (MM) contains cells related to the bone marrow tumor. However, identifying clonal cells in the blood of patients with monoclonal gammopathy of undetermined significance (MGUS) has been difficult. In this study, we analyzed blood mononuclear cells (BMNCs) from 16 patients with MGUS, 2 with amyloidosis, 8 with smoldering MM (SMM), 2 with indolent MM (IMM), and 15 with active MM using three different methods to detect and quantitate clonal cells, ie, immunofluorescence microscopy (IM) for monoclonal plasma cells, three-color flow cytometry (FC) for CD38(+)CD45- CD45(dim) cells, and the allele-specific oligonucleotide polymerase chain reaction (ASO-PCR). Using ASO-PCR, we were able to detect clonal cells in the blood in 13 of 16 patients with MGUS, 2 of 2 with amyloid, 6 of 8 with SMM, 2 of 2 with IMM, and 13 of 15 with MM. In 9 of the 13 patients with MGUS with blood involvement, the number of clonal cells was very small ( < 0.04% of the BMNCs). The median percentage of clonal cells as determined by ASO-PCR was 0.02 for MGUS, 0.02 for SMM, and 0.24 for MM. Clonal plasma cells or CD38+CD45-CD45(dim) cells were identified by IM or FC in 6 of 16 MGUS patients, 4 of 8 with SMM, and 11 of 15 with MM. In all cases in which IM or FC detected clonal cells, the ASO-PCR was positive. This study shows that, by using ASO-PCR, clonal cells can be found at very low levels in the blood in most patients with MGUS. However, the number of clonal cells in the blood of MGUS patients is less than those with overt MM (P = .006). In contrast to MGUS, patients with active MM are more likely to have identifiable clonal circulating plasma cells (P = .05).