J. F. San Miguel

Standardized RT-PCR analysis of fusion gene transcripts from chromosome aberrations in acute leukemia for detection of minimal residual disease. Report of the BIOMED-1 Concerted Action: investigation of minimal residual disease in acute leukemia.

Prospective studies on the detection of minimal residual disease (MRD) in acute leukemia patients have shown that large-scale MRD studies are feasible and that clinically relevant MRD-based risk group classification can be achieved and can now be used for designing new treatment protocols. However, multicenter international treatment protocols with MRD-based stratification of treatment need careful standardization and quality control of the MRD techniques. This was the aim of the European BIOMED-1 Concerted Action ‘Investigation of minimal residual disease in acute leukemia: international standardization and clinical evaluation’ with participants of 14 laboratories in eight European countries (ES, NL, PT, IT, DE, FR, SE and AT). Standardization and quality control was performed for the three main types of MRD techniques, ie flow cytometric immunophenotyping, PCR analysis of antigen receptor genes, and RT-PCR analysis of well-defined chromosomal aberrations. This study focussed on the latter MRD technique. A total of nine well-defined chromosome aberrations with fusion gene transcripts were selected: t(1;19) with E2A-PBX1, t(4;11) with MLL-AF4, t(8;21) with AML1-ETO, t(9;22) with BCR-ABL p190 and BCR-ABL p210, t(12;21) with TEL-AML1, t(15;17) with PML-RARA, inv (16) with CBFB-MYH11, and microdeletion 1p32 with SIL-TAL1. PCR primers were designed according to predefined criteria for single PCR (external primers A ↔ B) and nested PCR (internal primers C ↔ D) as well as for ‘shifted’ PCR with a primer upstream (E5′ primer) or downstream (E3′ primer) of the external A ↔ B primers. The ‘shifted’ E primers were designed for performing an independent PCR together with one of the internal primers for confirmation (or exclusion) of positive results. Various local RT and PCR protocols were compared and subsequently a common protocol was designed, tested and adapted, resulting in a standardized RT-PCR protocol. After initial testing (with adaptations whenever necessary) and approval by two or three laboratories, the primers were tested by all participating laboratories, using 17 cell lines and patient samples as positive controls. This testing included comparison with local protocols and primers as well as sensitivity testing via dilution experiments. The collaborative efforts resulted in standardized primer sets with a minimal target sensitivity of 10−2 for virtually all single PCR analyses, whereas the nested PCR analyses generally reached the minimal target sensitivity of 10−4. The standardized RT-PCR protocol and primer sets can now be used for molecular classification of acute leukemia at diagnosis and for MRD detection during follow-up to evaluate treatment effectiveness.

Prevention of thalidomide- and lenalidomide-associated thrombosis in myeloma

The incidence of venous thromboembolism (VTE) is more than 1‰ annually in the general population and increases further in cancer patients. The risk of VTE is higher in multiple myeloma (MM) patients who receive thalidomide or lenalidomide, especially in combination with dexamethasone or chemotherapy. Various VTE prophylaxis strategies, such as low-molecular-weight heparin (LMWH), warfarin or aspirin, have been investigated in small, uncontrolled clinical studies. This manuscript summarizes the available evidence and recommends a prophylaxis strategy according to a risk-assessment model. Individual risk factors for thrombosis associated with thalidomide/lenalidomide-based therapy include age, history of VTE, central venous catheter, comorbidities (infections, diabetes, cardiac disease), immobilization, surgery and inherited thrombophilia. Myeloma-related risk factors include diagnosis and hyperviscosity. VTE is very high in patients who receive high-dose dexamethasone, doxorubicin or multiagent chemotherapy in combination with thalidomide or lenalidomide, but not with bortezomib. The panel recommends aspirin for patients with ⩽1 risk factor for VTE. LMWH (equivalent to enoxaparin 40 mg per day) is recommended for those with two or more individual/myeloma-related risk factors. LMWH is also recommended for all patients receiving concurrent high-dose dexamethasone or doxorubicin. Full-dose warfarin targeting a therapeutic INR of 2–3 is an alternative to LMWH, although there are limited data in the literature with this strategy. In the absence of clear data from randomized studies as a foundation for recommendations, many of the following proposed strategies are the results of common sense or derive from the extrapolation of data from many studies not specifically designed to answer these questions. Further investigation is needed to define the best VTE prophylaxis.

Monoclonal gammopathy of undetermined significance (MGUS) and smoldering (asymptomatic) multiple myeloma: IMWG consensus perspectives risk factors for progression and guidelines for monitoring and management

Monoclonal gammopathy of undetermined significance (MGUS) was identified in 3.2% of 21 463 residents of Olmsted County, Minnesota, 50 years of age or older. The risk of progression to multiple myeloma, Waldenstroms macroglobulinemia, AL amyloidosis or a lymphoproliferative disorder is approximately 1% per year. Low-risk MGUS is characterized by having an M protein <15 g/l, IgG type and a normal free light chain (FLC) ratio. Patients should be followed with serum protein electrophoresis at six months and, if stable, can be followed every 2–3 years or when symptoms suggestive of a plasma cell malignancy arise. Patients with intermediate and high-risk MGUS should be followed in 6 months and then annually for life. The risk of smoldering (asymptomatic) multiple myeloma (SMM) progressing to multiple myeloma or a related disorder is 10% per year for the first 5 years, 3% per year for the next 5 years and 1–2% per year for the next 10 years. Testing should be done 2–3 months after the initial recognition of SMM. If the results are stable, the patient should be followed every 4–6 months for 1 year and, if stable, every 6–12 months.

Personalized therapy in multiple myeloma according to patient age and vulnerability: a report of the European Myeloma Network (EMN)

Most patients with newly diagnosed multiple myeloma (MM) are aged > 65 years with 30% aged > 75 years. Many elderly patients are also vulnerable because of comorbidities that complicate the management of MM. The prevalence of MM is expected to rise over time because of an aging population. Most elderly patients with MM are ineligible for autologous transplantation, and the standard treatment has, until recently, been melphalan plus prednisone. The introduction of novel agents, such as thalidomide, bortezomib, and lenalidomide, has improved outcomes; however, elderly patients with MM are more susceptible to side effects and are often unable to tolerate full drug doses. For these patients, lower-dose-intensity regimens improve the safety profile and thus optimize treatment outcome. Further research into the best treatment strategies for vulnerable elderly patients is urgently needed. Appropriate screening for vulnerability and an assessment of cardiac, pulmonary, renal, hepatic, and neurologic functions, as well as age > 75 years, at the start of therapy allows treatment strategies to be individualized and drug doses to be tailored to improve tolerability and optimize efficacy. Similarly, occurrence of serious nonhematologic adverse events during treatment should be carefully taken into account to adjust doses and optimize outcomes.

The use of bisphosphonates in multiple myeloma: recommendations of an expert panel on behalf of the European Myeloma Network

BACKGROUND Bisphosphonates (BPs) prevent, reduce, and delay multiple myeloma (MM)-related skeletal complications. Intravenous pamidronate and zoledronic acid, and oral clodronate are used for the management of MM bone disease. The purpose of this paper is to review the current evidence for the use of BPs in MM and provide European Union-specific recommendations to support the clinical practice of treating myeloma bone disease. DESIGN AND METHODS An interdisciplinary, expert panel of specialists on MM and myeloma-related bone disease convened for a face-to-face meeting to review and assess the evidence and develop the recommendations. The panel reviewed and graded the evidence available from randomized clinical trials, clinical practice guidelines, and the body of published literature. Where published data were weak or unavailable, the panel used their own clinical experience to put forward recommendations based solely on their expert opinions. RESULTS The panel recommends the use of BPs in MM patients suffering from lytic bone disease or severe osteoporosis. Intravenous administration may be preferable; however, oral administration can be considered for patients unable to make hospital visits. Dosing should follow approved indications with adjustments if necessary. In general, BPs are well tolerated, but preventive steps should be taken to avoid renal impairment and osteonecrosis of the jaw (ONJ). The panel agrees that BPs should be given for 2 years, but this may be extended if there is evidence of active myeloma bone disease. Initial therapy of ONJ should include discontinuation of BPs until healing occurs. BPs should be restarted if there is disease progression. CONCLUSIONS BPs are an essential component of MM therapy for minimizing skeletal morbidity. Recent retrospective data indicate that a modified dosing regimen and preventive measures can greatly reduce the incidence of ONJ.

Therapy-Related Acute Promyelocytic Leukemia

PURPOSE To analyze patient cases of therapy-related acute promyelocytic leukemia (tAPL), occurring after chemotherapy (CT), radiotherapy (RT) or both for a prior disorder, diagnosed during the last 20 years in three European countries. PATIENTS AND METHODS The primary disorder and its treatment, interval from primary disorder to tAPL, characteristics of tAPL, and its outcome were analyzed in 106 patients. RESULTS Eighty of the 106 cases of tAPL were diagnosed during the last 10 years, indicating an increasing incidence of tAPL. Primary disorders were predominantly breast carcinoma (60 patients), non-Hodgkins lymphoma (15 patients), and other solid tumors (25 patients). Thirty patients had received CT alone, 27 patients had received RT alone, and 49 patients had received both. CT included at least one alkylating agent in 68 patients and at least one topoisomerase II inhibitor in 61 patients, including anthracyclines (30 patients), mitoxantrone (28 patients), and epipodophyllotoxins (19 patients). Median interval from primary disorder to tAPL diagnosis was 25 months (range, 4 to 276 months). Characteristics of tAPL were generally similar to those of de novo APL. With treatment using anthracycline-cytarabine-based CT or all-trans-retinoic acid combined with CT, actuarial survival was 59% at 8 years. CONCLUSION tAPL is not exceptional, and develops usually less than 3 years after a primary neoplasm (especially breast carcinoma) treated in particular with topoisomerase II-targeted drugs (anthracyclines or mitoxantrone and less often etoposide). Characteristics and outcome of tAPL seem similar to those of de novo APL.

Prognostic value of immunophenotypic detection of minimal residual disease in acute lymphoblastic leukemia.

PURPOSE The identification of immunophenotypic aberrancies through multiparametric flow cytometry makes the differentiation between normal and leukemic cells relatively simple and quick, and is therefore an attractive method for the investigation of minimal residual disease (MRD). In this report, we have analyzed the impact on relapse and relapse-free survival (RFS) of detecting immunophenotypical aberrant cells in acute lymphoblastic leukemia (ALL) patients in cytomorphologic complete remission (CR). MATERIALS AND METHODS Two hundred eleven bone marrow (BM) samples from 53 consecutive ALL (37 precursor B-ALL and 16 T-ALL) patients were analyzed. The only selection criteria were to have at least one aberrant immunophenotypic feature at diagosis and to have achieved cytomorphologic CR after induction therapy. For MRD detection, all follow-up samples were analyzed with triple labelings using a two-step acquisition procedure, in which 106 cells were screened for the possible persistence of residual leukemic cells with the same phenotypic aberrancy as that identified diagnosis. RESULTS Patients who displayed a gradual increase in MRD levels showed a higher relapse rate (90% v22%; P < .00001) and shorter median RFS (12 months v not reached; P < .0001) than those with stable or decreasing MRD levels. This adverse prognostic influence also was observed when children and adults, as well as B-ALL and T-ALL patients, were analyzed separately. An MRD level > or = or greater than 10(-3) discriminated two risk groups of ALL patients with significantly different relapse rates and RFS at all treatment phases (end of induction, consolidation, maintenance, and out of treatment). CONCLUSION Multiparametric flow cytometry of MRD in ALL patients is a valuable tool for relapse prediction and for the identification of a cohort of patients with very poor prognosis.

Gene expression profiling of B lymphocytes and plasma cells from Waldenström's macroglobulinemia: comparison with expression patterns of the same cell counterparts from chronic lymphocytic leukemia, multiple myeloma and normal individuals.

The tumoral clone of Waldenströms macroglobulinemia (WM) shows a wide morphological heterogeneity, which ranges from B lymphocytes (BL) to plasma cells (PC). By means of genome-wide expression profiling we have been able to identify genes exclusively deregulated in BL and PC from WM, but with a similar expression pattern in their corresponding cell counterparts from chronic lymphocytic leukemia (CLL) and multiple myeloma (MM), as well as normal individuals. The differentially expressed genes have important functions in B-cell differentiation and oncogenesis. Thus, two of the genes downregulated in WM-BL were IL4R, which plays a relevant role in CLL B-cell survival, and BACH2, which participates in the development of class-switched PC. Interestingly, one of the upregulated genes in WM-BL was IL6. A set of four genes was able to discriminate clonal BL from WM and CLL: LEF1 (WNT/β-catenin pathway), MARCKS, ATXN1 and FMOD. We also found deregulation of genes involved in plasma cell differentiation such as PAX5, which was overexpressed in WM-PC, and IRF4 and BLIMP1, which were underexpressed. In addition, three of the target genes activated by PAX5 – CD79, BLNK and SYK – were upregulated in WM-PC. In summary, these results indicate that both PC and BL from WM are genetically different from the MM and CLL cell counterpart.

The oral combination of thalidomide, cyclophosphamide and dexamethasone (ThaCyDex) is effective in relapsed/refractory multiple myeloma

We evaluate the efficacy of the oral combination of thalidomide, cyclophosphamide and dexamethasone (ThaCyDex) in 71 refractory/relapsed multiple myeloma patients, including a prognostic analysis to predict both response and survival. Patients received thalidomide at escalating doses (200–800 mg/day), daily cyclophosphamide (50 mg/day) and pulsed dexamethasone (40 mg/day, 4 days every 3 weeks). On an intention-to-treat basis and using the EBMT response criteria, 2% patients reached complete response (CR), 55% partial response (PR) and 26% minor response (MR) yielding a total response (CR+PR+MR) rate of 83% after 3 months of therapy. After 6 months of therapy, responses were maintained including a 10% CR. The 2-year progression free and overall survival were 57 and 66%, respectively. A favorable response was associated with β2 microglobulin ⩽4 mg/dl, platelets >80 × 109/l and nonrefractory disease. Regarding survival, low β2 microglobulin (⩽4 mg/dl), age (⩽65 years) and absence of extramedullary myelomatous lesion were associated with a longer survival. Major adverse effects included constipation (24%), somnolence (18%), fatigue (17%) and infection (13%). Only 7% of patients developed a thrombo-embolic event. ThaCyDex is an oral regimen that induces a high response rate and long remissions, particularly in relapsing patients with β2 microglobulin ⩽4 mg/dl and ⩽65 years.

Prognostic and biological implications of genetic abnormalities in multiple myeloma undergoing autologous stem cell transplantation: t(4;14) is the most relevant adverse prognostic factor, whereas RB deletion as a unique abnormality is not associated with adverse prognosis.

Fluorescence in situ hybridization (FISH) has become a powerful technique for prognostic assessment in multiple myeloma (MM). However, the existence of associations between cytogenetic abnormalities compels us to re-assess the value of each abnormality. A total of 260 patients with MM at the time of diagnosis, enrolled in the GEM-2000 Spanish transplant protocol, have been analyzed by FISH in order to ascertain the independent influence on myeloma prognosis of IGH translocations, as well as RB and P53 deletions. Survival analyses showed that patients with t(4;14), RB or P53 deletions had a significantly shorter survival than patients without these abnormalities. However, patients with RB deletions without other abnormalities in FISH analysis, displayed a similar outcome to those patients without genetic changes by FISH (46 vs 54 months, P=0.3). In the multivariate analysis the presence of t(4;14), RB deletion associated with other abnormalities, age >60 years, high proportion of S-phase cells and advanced stage of the disease according to the International Staging System retained their independent prognostic influence. In summary, RB deletion as a sole abnormality does not lead to a shortening in the survival of MM patients, whereas t(4;14) confers the worst prognosis in MM patients treated with high-dose chemotherapy.