Faculty Bibliography

Polymerase chain reaction (PCR) assessment of clonal immunoglobulin (Ig) and T-cell receptor (TCR) gene rearrangements is an important diagnostic tool in mature B-cell neoplasms. However, lack of standardized PCR protocols resulting in a high level of false negativity has hampered comparability of data in previous clonality studies. In order to address these problems, 22 European laboratories investigated the Ig/TCR rearrangement patterns as well as t(14;18) and t(11;14) translocations of 369 B-cell malignancies belonging to five WHO-defined entities using the standardized BIOMED-2 multiplex PCR tubes accompanied by international pathology panel review. B-cell clonality was detected by combined use of the IGH and IGK multiplex PCR assays in all 260 definitive cases of B-cell chronic lymphocytic leukemia (n=56), mantle cell lymphoma (n=54), marginal zone lymphoma (n=41) and follicular lymphoma (n=109). Two of 109 cases of diffuse large B-cell lymphoma showed no detectable clonal marker. The use of these techniques to assign cell lineage should be treated with caution as additional clonal TCR gene rearrangements were frequently detected in all disease categories. Our study indicates that the BIOMED-2 multiplex PCR assays provide a powerful strategy for clonality assessment in B-cell malignancies resulting in high Ig clonality detection rates particularly when IGH and IGK strategies are combined.

The aim of the study was to evaluate whether adequate stem cells (CD34+) could be harvested at presentation in myeloma patients such that high dose melphalan (HDM) with autologous stem cell rescue can be offered as primary therapy. The regimes either involved no prior cytoreductive chemotherapy (steroids only, n = 31) or a single course of VAD (n = 22). The median number of CD34 cells collected with steroids was 1.3 x 10(6) (0.2-5.6) compared to 4.6 x 10(6) (0.3-19.2) cells/kg with VAD (P < 0.0001). We conclude that it is possible to collect stem cells from myeloma patients at presentation with minimal prior therapy. Using this strategy, of a single prior course of chemotherapy followed by immediate harvest, it is feasible to offer early high-dose therapy in clinical situations where this is important.

Veno-occlusive disease (VOD) is a common and high-risk complication of allogeneic stem cell transplantation (SCT). Defibrotide has recently been used successfully to treat the disorder. We report on 58 patients who received defibrotide prophylaxis without concurrent heparin. No patients fulfilled the Baltimore criteria for VOD or died of the condition within 100 days of SCT. None of this group developed haemorrhagic complications secondary to defibrotide. These observations suggest that prophylaxis with defibrotide alone may reduce the incidence of VOD post-SCT although a randomised controlled trial is warranted to further evaluate its role.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Peripheral blood stem cells (PBSC) following reduced intensity conditioning (RIC) are being increasingly used for allogeneic transplantation in multiple myeloma. The purpose of this study was to compare outcome of patients transplanted with either PBSC or bone marrow (BM) following RIC or myeloablative conditioning (MAC). DESIGN AND METHODS/METHODS:Data from 1,667 patients who had received an allogeneic identical sibling donor transplant for multiple myeloma from 1994 to 2003 were analyzed. Comparisons were made between results of PBSC and BM transplants after conditioning with RIC or MAC. RESULTS:The engraftment rate was faster with PBSC than with BM (median: 14 and 18 days for neutrophils and 15 and 25 days for platelets respectively) irrespectively of whether RIC or MAC was used. The incidence of acute graft-versus-host disease (GVHD) did not differ significantly between the groups while chronic GVHD was more prevalent in PBSC recipients irrespectively of whether they had RIC or MAC. Non-relapse mortality did not differ between PBSC and BM recipients, but was significantly higher in those treated with MAC than in those given RIC irrespectively of the cell source. The relapse/progression rate did not differ between PBSC and BM recipients, but was significantly higher in those given RIC, irrespectively of the cell source. There was no significant difference in overall or progression-free survival between patients given PBSC or BM transplants. INTERPRETATION AND CONCLUSIONS/CONCLUSIONS:Although transplantation of PBSC is associated with faster engraftment and more frequent chronic GVHD, overall survival, non-relapse mortality, relapse/progression and progression-free survival are similar to those following BM transplants. However both PBSC and BM transplants are associated with lower non-relapse mortality, lower response rate and higher relapse/progression if RIC is used instead of MAC.

In vivo and in vitro studies suggest human growth hormone (hGH) receptors on bone marrow stem cells may be biologically active and could be exploited to promote haemopoetic recovery after intensive chemotherapy. Patients with haematological malignancies receiving intensive chemotherapy and requiring hospitalization were randomized in a double-blind, placebo-controlled single-centre trial. Patients were randomly assigned to receive either hGH 500 microg/day or placebo, for 6 weeks. There was no significant difference in patient characteristics at baseline between the placebo and treatment arms. Patients treated with hGH showed significantly faster recovery of platelets to 25 x 10(9)/l (median of 16 versus 19 days; P = 0.03) compared to the placebo-controlled arm (hazard ratio 1.47 favouring hGH, 95% confidence interval (CI), 1.03-2.08). Time to relapse did not differ significantly between arms. There was no change in the anthropometric parameters at the start and end of hGH/placebo therapy. The study drug was well tolerated. Treatment with hGH in physiological doses improves platelet recovery, but is not associated with a lower relapse rate or improved anthropometric parameters in patients receiving intensive chemotherapy.

PURPOSE/OBJECTIVE:To compare the effects of pegylated interferon-alpha2b (P-IFN) and interferon-alpha2b (IFN) on quality of life (QoL) and toxicity in patients with multiple myeloma maintained on a steady dose of IFN. PATIENTS AND METHODS/METHODS:Consenting, eligible myeloma patients on IFN maintenance therapy for at least 6 weeks were randomly (1:1) allocated to receive P-IFN for 3 months followed by IFN for 3 months, or to continue with IFN for 3 months followed by P-IFN for 3 months (cross-over design). Patients were assessed for toxicity and QoL. Dose of P-IFN was equivalent to IFN. RESULTS:The study enrolled 60 patients. At enrollment, 35 patients were in complete remission, 20 in partial remission and 5 were minimal responders. P-IFN was associated with significantly better global QoL score (mean difference 8.4; P = 0.0002). There was a significant improvement in functional scales--physical (P = 0.03), emotional (P = 0.04), social (P = 0.0008) with P-IFN. Fatigue (P = 0.0003), pain (P = 0.02) and appetite loss (P = 0.003) symptom scales were less in patients while on P-IFN. There were no statistically significant differences between treatment arms in QoL as measured by QLQ-MY24. CONCLUSION/CONCLUSIONS:These data suggest that patients on P-IFN have a better QoL. Dose escalation studies are warranted to investigate potential impact on survival.

Increased long-term survival seen in patients with solid and hematologic cancers achieved as a result of aggressive chemoradiotherapy has come at a price. Therapy-related acute myeloid leukemia has been frequently documented in these patient cohorts, and its biology well studied. Recognition of secondary non-Hodgkin lymphoma as a cause of significant morbidity and mortality in these patients is equally important. The patterns of incidence and latency of secondary lymphomas is distinct from that of myeloid malignancies and other solid cancers. We have systematically analyzed and summarized reports from various groups over the last three decades. Risk of secondary lymphomas increases after the first 5 years of completion of chemotherapy or radiotherapy and persists for more than three decades. This reinforces the need for long-term follow-up of all patients exposed to chemoradiotherapy and confirms that chemotherapeutic agents can cause lymphoma.

A greater understanding of the biology of myeloma has focused research on the identification of novel target-based treatment strategies. Proteasome inhibition represents one such approach and the introduction of bortezomib, the first-in-class proteasome inhibitor, has been a major breakthrough in the treatment of multiple myeloma. As a result of its novel mechanism of action, bortezomib has been shown to induce responses in patients previously refractory to treatment, and results in increased progression-free and overall survival rates. The current understanding of the biology of the proteasome and the mechanism by which proteasome inhibition leads to myeloma cell death is described in this review. The role of proteasome inhibitors in the management of myeloma is also discussed.

Plasma cells producing high levels of paraprotein are dependent on the unfolded protein response (UPR) and chaperone proteins to ensure correct protein folding and cell survival. We hypothesized that disrupting client-chaperone interactions using heat shock protein 90 (Hsp90) inhibitors would result in an inability to handle immunoglobulin production with the induction of the UPR and myeloma cell death. To study this, myeloma cells were treated with Hsp90 inhibitors as well as known endoplasmic reticulum stress inducers and proteasome inhibitors. Treatment with thapsigargin and tunicamycin led to the activation of all 3 branches of the UPR, with early splicing of XBP1 indicative of IRE1 activation, upregulation of CHOP consistent with ER resident kinase (PERK) activation, and activating transcription factor 6 (ATF6) splicing. 17-AAG and radicicol also induced splicing of XBP1, with the induction of CHOP and activation of ATF6, whereas bortezomib resulted in the induction of CHOP and activation of ATF6 with minimal effects on XBP1. After treatment with all drugs, expression levels of the molecular chaperones BiP and GRP94 were increased. All drugs inhibited proliferation and induced cell death with activation of JNK and caspase cleavage. In conclusion, Hsp90 inhibitors induce myeloma cell death at least in part via endoplasmic reticulum stress and the UPR death pathway.