International prognostic scoring system for mastocytosis (IPSM): a retrospective cohort study

BACKGROUND

The WHO classification separates mastocytosis into distinct variants, but prognostication remains a clinical challenge. The aim of this study was to improve prognostication for patients with mastocytosis.

METHODS

We analysed data of the registry of the European Competence Network on Mastocytosis including 1639 patients (age 17-90 years) diagnosed with mastocytosis according to WHO criteria between Jan 12, 1978, and March 16, 2017. Univariate and multivariate analyses with Cox regression were applied to identify prognostic variables predicting survival outcomes and to establish a prognostic score. We validated this International Prognostic Scoring System in Mastocytosis (IPSM) with data of 462 patients (age 17-79 years) from the Spanish network Red Española de Mastocitosis diagnosed between Jan 22, 1998, and Nov 2, 2017.

FINDINGS

The prognostic value of the WHO classification was confirmed in our study (p<0·0001). For patients with non-advanced mastocytosis (n=1380), we identified age 60 years or older (HR 10·75, 95% CI 5·68-20·32) and a concentration of alkaline phosphatase 100 U/L or higher (2·91, 1·60-5·30) as additional independent prognostic variables for overall survival. The resulting scoring system divided patients with non-advanced mastocytosis into three groups: low (no risk factors), intermediate 1 (one risk factor), and intermediate 2 (two risk factors). Overall survival and progression-free survival differed significantly among these groups (p<0·0001). In patients with advanced mastocytosis (n=259), age 60 years or older (HR 2·14, 95% CI 1·42-3·22), a concentration of tryptase 125 ng/mL or higher (1·81, 1·20-2·75), a leukocyte count of 16 × 10⁹ per L or higher (1·88, 1·27-2·79), haemoglobin of 11 g/dL or lower (1·71, 1·13-2·57), a platelet count of 100 × 10⁹ per L or lower (1·63, 1·13-2·34), and skin involvement (0·46, 0·30-0·69) were prognostic variables. Based on these variables, a separate score for advanced mastocytosis with four risk categories was established, with significantly different outcomes for overall survival and progression-free survival (p<0·0001). The prognostic value of both scores was confirmed in 413 patients with non-advanced disease and 49 with advanced mastocytosis from the validation cohort.

INTERPRETATION

The IPSM scores for patients with non-advanced and advanced mastocytosis can be used to predict survival outcomes and guide treatment decisions. However, the predictive value of the IPSM needs to be confirmed in forthcoming trials.

FUNDING

Austrian Science Fund, Deutsche Forschungsgemeinschaft, Koeln Fortune Program, Charles and Ann Johnson Foundation, Instituto de Salud Carlos III, Fondos FEDER, Research-Foundation Flanders/Fonds Wetenschappelijk Onderzoek, Clinical Research-Fund of the University Hospitals Leuven, and Research-Foundation Flanders/Fonds Wetenschappelijk Onderzoek.

The Data Registry of the European Competence Network on Mastocytosis (ECNM): Set Up, Projects, and Perspectives

Mastocytosis is a unique hematologic neoplasm with complex biology and pathology and a variable clinical course. The disease can essentially be divided into cutaneous mastocytosis (CM) and systemic mastocytosis (SM). In adults, SM is diagnosed in most cases and manifests as either indolent or advanced disease. Patients with advanced SM have an unfavorable prognosis with reduced survival. However, so far, little is known about the prevalence of various categories of SM and about prognostic factors. In an attempt to learn more about the behavior and evolution of various forms of CM and SM, the European Competence Network on Mastocytosis (ECNM) initiated a mastocytosis registry in 2012. In this article, the set up and start phase of this registry are described. Until 2018, more than 3000 patients from 12 countries and 25 centers have been enrolled. In a majority of all patients, robust follow-up data and relevant clinical end points are available. Using this data set, a series of registry projects have been launched, with the aim to validate previously identified diagnostic and prognostic variables and to identify new disease-related and patient-related parameters in various forms of mastocytosis. Moreover, the core data set of the registry will be useful to establish multiparametric scoring systems through which prognostication and individualized management of patients with mastocytosis should improve in the foreseeable future.

The Italian Mastocytosis Registry: 6-year experience from a hospital-based registry

Aim: We collected ‘real-life’ data on the management of patients with mastocytosis in the Italian Mastocytosis Registry. Methods: Six hundred patients diagnosed with mastocytosis between 1974 and 2014 were included from 19 centers. Results: Among adults (n = 401); 156 (38.9%) patients were diagnosed with systemic mastocytosis. In 212 adults, no bone marrow studies were performed resulting in a provisional diagnosis of mastocytosis of the skin. This diagnosis was most frequently established in nonhematologic centers. In total, 182/184 pediatric patients had cutaneous mastocytosis. We confirmed that in the most patients with systemic mastocytosis, serum tryptase levels were >20 ng/ml and KIT D816V was detectable. Conclusion: The Italian Mastocytosis Registry revealed some center-specific approaches for diagnosis and therapy. Epidemiological evidence on this condition is provided.

SETD2 and histone H3 lysine 36 methylation deficiency in advanced systemic mastocytosis

The molecular basis of advanced systemic mastocytosis (SM) is not fully understood and despite novel therapies the prognosis remains dismal. Exome sequencing of an index-patient with mast cell leukemia (MCL) uncovered biallelic loss-of-function mutations in the SETD2 histone methyltransferase gene. Copy-neutral loss-of-heterozygosity at 3p21.3 (where SETD2 maps) was subsequently found in SM patients and prompted us to undertake an in-depth analysis of SETD2 copy number, mutation status, transcript expression and methylation levels, as well as functional studies in the HMC-1 cell line and in a validation cohort of 57 additional cases with SM, including MCL, aggressive SM and indolent SM. Reduced or no SETD2 protein expression—and consequently, H3K36 trimethylation—was found in all cases and inversely correlated with disease aggressiveness. Proteasome inhibition rescued SETD2 expression and H3K36 trimethylation and resulted in marked accumulation of ubiquitinated SETD2 in SETD2-deficient patients but not in patients with near-normal SETD2 expression. Bortezomib and, to a lesser extent, AZD1775 alone or in combination with midostaurin induced apoptosis and reduced clonogenic growth of HMC-1 cells and of neoplastic mast cells from advanced SM patients. Our findings may have implications for prognostication of SM patients and for the development of improved treatment approaches in advanced SM.

Narrow-band UVB phototherapy and psoralen-ultraviolet A photochemotherapy in the treatment of cutaneous mastocytosis: a study in 20 patients

BACKGROUND

In mastocytosis, the skin is almost invariably involved, and cutaneous symptoms deeply affect patients' quality of life.

METHODS

A retrospective observational analysis of patients affected by cutaneous mastocytosis (CM) and indolent systemic mastocytosis (ISM) treated with phototherapy/photochemotherapy (PUVA or NB-UVB) has been conducted. For each patient, total numbers of PUVA or NB-UVB exposures, the cumulative UV dose (J/cm² ), serum tryptase profile, and pruritus, before and after treatment, according to the visual analogue scale (VAS) were considered. Skin lesions of each patient were assessed, before and after treatment, according to a cutaneous scale score.

RESULTS

Twenty patients affected by CM and ISM were studied; in particular, 10 patients received NB-UVB therapy, and other 10 patients received PUVA. A statistically significant mean reduction of pruritus in both groups (P < 0.01) was observed. The number of treatments necessary to obtain symptom relief was significantly lower in the PUVA group, but the mean exposure dose was significantly higher, if compared to the NB-UVB group. Serum tryptase levels showed a downward trend. The cutaneous score improved in both groups.

LIMITATIONS

This study was a retrospective study with a small sample size and without a control group.

CONCLUSION

This work provides evidence that both NB-UVB and PUVA represent a safe and useful second-line therapy of the cutaneous symptoms in mastocytosis.

Clinical presentation and management practice of systemic mastocytosis. A survey on 460 Italian patients

Systemic mastocytosis is a rare heterogeneous myeloproliferative neoplasm characterized by abnormal proliferation and activation of mast cells. We describe a large multicentre series of 460 adult patients with systemic mastocytosis, with a diagnosis based on WHO 2008 criteria, in a "real-life" setting of ten Italian centers with dedicated multidisciplinary programs. We included indolent forms with (n = 255) and without (n = 165) skin lesions, smouldering (n = 20), aggressive (n = 28), associated with other hematological diseases mastocytosis (n = 21) and mast cell leukemia (n = 1). This series was uniquely characterized by a substantial proportion of patients with low burden of neoplastic mast cells; notably, 38% of cases were diagnosed using only minor diagnostic criteria according to WHO 2008 classification, underlying the feasibility of early diagnosis where all diagnostic approaches are made available. This has particular clinical relevance for prevention of anaphylaxis manifestations, that were typically associated with indolent forms. In multivariate analysis, the most important features associated with shortened overall survival were disease subtype and age at diagnosis >60 years. Disease progression was correlated with mastocytosis subtype and thrombocytopenia. As many as 32% of patients with aggressive mastocytosis suffered from early evolution into acute leukemia. Overall, this study provides novel information about diagnostic approaches and current presentation of patients with SM and underlines the importance of networks and specialized centers to facilitate early diagnosis and prevent disease-associated manifestations. Am. J. Hematol. 91:692-699, 2016. © 2016 Wiley Periodicals, Inc.

'Real-life' study of imatinib therapy in chronic phase-chronic myeloid leukemia: A novel retrospective observational longitudinal analysis

OBJECTIVES

Imatinib is a cornerstone of treatment of chronic myeloid leukemia. It remains unclear whether transient treatment discontinuation or dose changes affect outcome and this approach has not yet been approved for use outside clinical trials.

METHODS

We conducted a retrospective single-institution observational study to evaluate factors affecting response in 'real-life' clinical practice in 138 chronic myeloid leukemia patients in chronic phase treated with imatinib. We used a novel longitudinal data analytical model, with a generalized estimating equation model, to study BCR-ABL variation according to continuous standard dose, change in dose or discontinuation; BCR-ABL transcript levels were recorded. Treatment history was subdivided into time periods for which treatment was given at constant dosage (total 483 time periods). Molecular and cytogenetic complete response was observed after 154 (32%) and 358 (74%) time periods, respectively.

RESULTS

After adjusting for length of time period, no association between dose and cytogenetic complete response rate was observed. There was a significantly lower molecular complete response rate after time periods at a high imatinib dosage.

DISCUSSION

This statistical approach can identify individual patient variation in longitudinal data collected over time and suggests that changes in dose or discontinuation of therapy could be considered in patients with appropriate biological characteristics.

Reduced DNA methylation and hydroxymethylation in patients with systemic mastocytosis

OBJECTIVE

As disruption of epigenetic control is a frequent event in solid tumors and leukemia, we investigated changes in DNA methylation (5mC) and hydroxymethylation (5hmC) in patients with systemic mastocytosis (SM), a rare myeloproliferative disease with a wide spectrum of severity, characterized by the accumulation of mast cells in various organs.

METHODS

We measured overall genomic levels of 5hmC and 5mC in patients with SM by dot blot, as well as by quantitative immunofluorescence in samples of cutaneous mastocytosis.

RESULTS

Overall 5hmC levels were reduced in all patients with SM, but to a greater extent in the presence of higher D816V mutational load in the KIT oncogene, which affects prognosis and therapeutic options in these patients. Loss of 5hmC was likely due to systemic effects of SM as it did not correlate with overall mast cell burden in these patients, nor it was due to inactivating mutations of TET2 or reduced TET2 expression.

CONCLUSIONS

The correlation between SM diagnosis and significantly low 5hmC levels suggests that reduction of 5hmC represents a systemic effect of SM that may be useful for patient stratification and that measurements of 5hmC levels may serve as a better prognostic marker than TET2 mutations.

Long term outcome of Ph+ CML patients achieving complete cytogenetic remission with interferon based therapy moving from interferon to imatinib era

Interferon α (IFNα) prolongs survival of CML patients achieving CCyR and potentially synergizes with TKIs. We report on the molecular status and long term outcome of 121 patients who were treated in Italy between 1986 and 2000 with IFNα based therapy and who obtained CCyR. After a median follow up of 16.5 years, 74 (61%) patients were switched to standard imatinib: 48 (65%) lost the CCyR on IFNα, and 36 (75%) are alive and in CCyR; 26 (35%) were switched to imatinib when they were still in CCyR on IFNα, and all 26 are alive and in CCyR. Forty-seven patients (39%) were never switched to imatinib: 24 (51%) continued and 23 (49%) discontinued IFNα, respectively, and 39/47 (83%) are alive and in CCyR. At last follow-up, the BCR-ABL transcripts level was available in 96/101 living patients (95%) The BCR-ABL:ABL ratio was between 0.1 and 0.01% (MR(3.0) ) in 17%, and less than 0.01% (MR(4.0) ) in 81% of patients. No patient was completely molecular negative (MR(4.5) or MR(5.0) ). The OS at 10 and 20 years is 92 and 84%, respectively. This study confirms that CCyR achieved with IFNα and maintained with or without imatinib or any other therapy significantly correlates with long term survival in CML patients who mostly have MR(4.0) . Complete molecular response (MR(4.5) or MR(5.0) ) seems to be unnecessary for such a long survival. This study further supports development of studies testing the clinical effect of the combinations of TKIs with IFNα.

The development of peripheral T-cell lymphoma after successful treatment for diffuse large B-cell lymphoma in a patient with suspected adult onset immunodeficiency: more questions than answers?

We present the case of a 60-year-old woman who developed peripheral T-cell lymphoma following successful treatment for high-grade B-cell non-Hodgkin's lymphoma. We consider the possible aetiology of this unusual occurrence. We hypothesise that this case represents one of the undiagnosed adult-onset immunodeficiency, in which the pathogenesis of the patient's T-cell lymphoma may have been in part iatrogenic, namely related to previous immunotherapy with rituximab. We feel this case highlights the importance of rebiopsy in patients with recurrent lymphadenopathy and a history of haematological malignancy and hence acts as an important aide memoir in the investigation of such cases.

The role of miRNAs in mast cells and other innate immune cells

MicroRNAs (miRNAs) are a large class of small regulatory molecules able to control translation of target mRNAs and consequently to regulate various biological processes at a posttranscriptional level. Their importance is highlighted by the fact that altered miRNA expression is linked to a variety of human diseases, particularly cancer. Accordingly, miRNA biogenesis itself must be carefully regulated, both transcriptionally and posttranscriptionally. Here, we focus on the role of miRNAs in three lineages of myeloid cells important in both innate and acquired immunity: mast cells, macrophages, and dendritic cells. These three cell types are strategically located throughout the body tissues, where they can respond to foreign material, danger, and inflammatory signals. We discuss the role of miRNAs in these cell types, with a special focus on three of the most extensively studied miRNAs, namely miR-221, miR-146a, and miR-155. We also discuss the role of cell-to-cell transfer of miRNAs in dendritic cells, mast cells, and macrophages, and we speculate about possible future directions in the field.

BCR-ABL kinase domain mutations and resistance in Ph+ acute lymphoblastic leukemia from the imatinib to the second-generation TKI era

6531

Background: Advent of 2nd-generation TKIs has brought additional treatment options for Philadelphia-positive (Ph+) acute lymphoblastic leukemia (ALL) patients (pts). To analyze the changes they have determined in mutation frequency and type, we have reviewed the database recording the results of BCR-ABL mutation analyses done in our laboratory from 2004 through 2011. Methods: 781 tests on 258 pts were performed by direct sequencing. Results: 143 pts were analyzed because of imatinib resistance; 101 (71%) had one or more mutations (a single mutation in 91 pts; two mutations in 10 pts). Three mutation types were by far the most frequent: T315I (38 pts, 37%), E255K (19 pts, 18%) and Y253H (19 pts, 18%). Of 84 pts who had developed resistance to 2nd- or 3rd-line therapy with dasatinib, nilotinib or bosutinib after imatinib failure, 65 (77%) were positive for Bcr-Abl mutations; 30 (46%) carried multiple mutations (up to four) and in 19 of them (63%) this was consequence of multiple lines of therapy. The most frequent newly acquired mutation in this setting was the T315I, detected in 35/57 (61%) cases acquiring mutations on dasatinib. Mutation analysis was also performed in 15 resistant pts enrolled in a study of dasatinib as 1st-line treatment of Ph+ ALL; 12 pts were positive, 11 of them had a T315I. Taking advantage of a next-generation sequencer (Roche 454), allowing a high sensitive and quantitative mutation scanning of Bcr-Abl, serially collected samples from 24 selected cases who developed mutations and resistance to one or more TKIs were retrospectively analyzed to study the kinetics of expansion of mutant clones. Results will be presented. Conclusions: Although 2nd generation TKIs are more potent and have much fewer insensitive mutations, long-term disease control remains a problem and the T315I becomes an even tougher enemy. The high genetic instability fosters mutational events anytime during TKI treatment and some mutation types (T315I, Y253H) have been observed to emerge and take over very quickly (from <0.01% to 90% in one-two months). Supported by PRIN, AIL, AIRC, Fondazione CARISBO.

Indolent systemic mastocytosis treated with narrow-band UVB phototherapy: study of five cases

BACKGROUND

Mastocytoses represent a heterogeneous group of stem cell disorders marked by an abnormal hyperplasia and accumulation of mast cells in one or more tissues, including bone marrow, gastrointestinal tract, liver, spleen, lymph nodes and skin. Indolent systemic mastocytosis (ISM) is characterized by red-brownish and pruriginous maculopapular lesions, a bone marrow infiltration without functional impairment and an indolent clinical course with a good prognosis. In particular, the most common cutaneous symptoms are urticarial rash and mild-to-high pruritus.

OBJECTIVES

This study analyses the clinical outcome of patients affected by ISM with prevalent pruriginous cutaneous symptoms and a scarce response to anti-histamines treated using narrowband ultraviolet B (NB-UVB) phototherapy.

METHODS

Narrowband ultraviolet B phototherapy was administered in a UV-irradiation cabin equipped with fluorescent UVB lamps with a peak emission at 311-313 nm. The perception of pruritus severity was assessed using the Visual Analogue Scale (VAS) before starting the treatment and at each control.

RESULTS

A complete remission of the cutaneous lesions and pruritus was documented in all patients after a median of 40.3 UV treatments and a median cumulative dose of 51.4 J/cm(2), with a lasting remission over a 6-month follow-up. The median VAS score at the beginning of the treatment was 86.6 (SD=6.64), whereas it decreased to 6.66 (SD=3.75) after 3 months of therapy.

CONCLUSIONS

Our work provides evidence that NB-UVB phototherapy is useful for the treatment of the cutaneous symptoms and pruritus in ISM.

The long-term durability of cytogenetic responses in patients with accelerated phase chronic myeloid leukemia treated with imatinib 600 mg: the GIMEMA CML Working Party experience after a 7-year follow-up

BACKGROUND

Imatinib mesylate is the first line treatment for chronic myeloid leukemia. The advent of imatinib increased survival significantly in patients in an advanced phase of the disease. However, few long-term data on the outcome of these patients based on large, prospective and controlled trials are available.

DESIGN AND METHODS

A phase 2 multicenter trial of the use of imatinib 600 mg/daily in patients with accelerated phase chronic myeloid leukemia was sponsored and promoted by the Italian Cooperative Study Group on Chronic Myeloid Leukemia in 2001.

RESULTS

One hundred and eleven patients were enrolled; the median follow-up of the 41 living patients is 82 months (range, 73-87). One hundred and seven patients (96%) returned to chronic phase and 79 patients (71%) achieved a complete hematologic response. Cumulative best rates of major cytogenetic response and complete cytogenetic response were 30% and 21%, respectively. All responses were maintained for a minimum of 4 weeks. At last follow-up, four patients were alive in complete remission after allogeneic transplant, 16 patients (14%) had switched to a second generation tyrosine kinase inhibitor and 21 patients (19%) were alive on imatinib therapy. No late toxicities were observed. Progression-free survival and event-free survival rates were 36.5% and 15%, respectively, at 7 years. The median survival time was 37 months, and was significantly associated with the achievement of a complete hematologic response or a complete cytogenetic response.

CONCLUSIONS

Imatinib may induce durable responses, associated with prolonged survival, in patients with accelerated phase chronic myeloid leukemia.

The efficacy of imatinib mesylate in patients with FIP1L1-PDGFR -positive hypereosinophilic syndrome. Results of a multicenter prospective study

BACKGROUND AND OBJECTIVES

The hypereosinophilic syndrome (HES) may be associated with the fusion of the platelet derived growth factor receptor a (PDGFRalpha) gene with the FIP1L1 gene in chromosome 4 coding for a constitutively activated PDGFRalpha tyrosine kinase. These cases with FIP1L1-PDGFRalpha rearrangement have been reported to be very sensitive to the tyrosine kinase inhibitor imatinib mesylate.

DESIGN AND METHODS

A prospective multicenter study of idiopathic or primary HES was established in 2001 (Study Protocol Registration no. NCT 0027 6929). One hundred and ninety-six patients were screened, of whom 72 where identified as having idiopathic or primary HES and 63 were treated with imatinib 100 to 400 mg daily.

RESULTS

Twenty-seven male patients carried the FIP1L1-PDGFRalpha rearrangement. All 27 achieved a complete hematologic remission (CHR) and became negative for the fusion transcripts according to reverse transcriptase polymerase chain reaction (RT-PCR) analysis. With a median follow-up of 25 months (15-60 months) all 27 patients remain in CHR and RT-PCR negative, and continue treatment at a dose of 100 to 400 mg daily. In three patients imatinib treatment was discontinued for few months, the fusion transcript became rapidly detectable, and then again undetectable upon treatment reassumption. Thirty-six patients did not carry the rearrangement; of these, five (14%) achieved a CHR, which was lost in all cases after 1 to 15 months.

INTERPRETATION AND CONCLUSIONS

All patients meeting the criteria for idiopathic or primary HES should be screened for the FIP1L1-PDGFRalpha rearrangement. For all patients with this rearrangement, chronic imatinib treatment at doses as low as 100 mg daily ensures complete and durable responses.

A novel denaturing high-performance liquid chromatography (D-HPLC) based method for kit mutation screening of patients (pts) with systemic mastocytosis (SM)

7085

Background: SM is characterized by activating mutations of Kit tyrosine kinase. While the enzimatic site (ES) type mutation D816V renders Kit resistant to imatinib, regulatory type mutations are sensitive to inhibition. Kit mutations screening with sensitive methods is important for an appropriate therapeutic management of SM. Methods: Our aims were: to set up and optimize a D-HPLC-based screening method for mutations in critical regions of Kit; to assess the sensitivity and reliability of our D-HPLC assay as compared to RFLP analysis; to characterize additional mutations. The analysis was performed on 51 SM pts. Results: For each sample, a RT-PCR product spanning the catalytic and activation loops (ES) was screened in parallel by D-HPLC, followed by sequencing of D-HPLC-positive cases, and by RFLP according to an reported method for the D816V detection. By RFLP analysis, 34/51 pts were positive for the D816V. By D- HPLC analysis, an abnormal eluition profile was seen in 36/51 pts - all the 34 RFLP-positive cases as well as two additional pts. Direct sequencing confirmed the presence of the D816V in all the 34 RFLP-positive cases and showed that in two of these cases a I798I polymorphism was also present. The two pts scored positive by D-HPLC but negative by RFLP were found to have the I798I polymorphism. The 15 pts who did not harbour ES type mutations were further investigated by D-HPLC analysis of a RT-PCR product spanning the transmembrane (TM) and juxtamembrane (JM) domains. D-HPLC showed an abnormal elution profile in 5 pts. By direct sequencing one patient showed the K546K mutation and 4 pts showed the M541L polymorphism. Conclusions: Our D-HPLC-based assay proved a straightforward, reliable and sensitive method for Kit mutation analysis and highlighted the importance of screening for mutations other than the D816V.

No significant financial relationships to disclose.

WT1 transcript amount discriminates secondary or reactive eosinophilia from idiopathic hypereosinophilic syndrome or chronic eosinophilic leukemia

Idiopathic hypereosinophilic syndromes (HES) comprise a spectrum of indolent to aggressive diseases characterized by persistent hypereosinophilia. Hypereosinophilia can result from the presence of a defect in the hematopoietic stem cell giving rise to eosinophilia, it can be present in many myeloproliferative disorders or alternatively it may be a reactive form, secondary to many clinical conditions. The hybrid gene FIP1L1-PDGRFalpha was identified in a subset of patients presenting with HES or chronic eosinophilic leukemia (CEL). In spite of this, the majority of HES patients do not present detectable molecular lesions and for many of them the diagnosis is based on exclusion criteria and sometimes it remains doubt. In this study we explored the possibility to distinguish between HES/CEL and reactive hypereosinophilia based on WT1 transcript amount. For this purpose, 312 patients with hypereosinophilia were characterized at the molecular and cytogenetic level and analyzed for WT1 expression at diagnosis and during follow-up. This study clearly demonstrates that WT1 quantitative assessment allows to discriminate between HES/CEL and reactive eosinophilia and represents a useful tool for disease monitoring especially in the patients lacking a marker of clonality.

Achieving a Major Molecular Response at the Time of a Complete Cytogenetic Response (CCgR) Predicts a Better Duration of CCgR in Imatinib-Treated Chronic Myeloid Leukemia Patients

PURPOSE

Most patients with chronic-phase chronic myeloid leukemia (CML) who receive imatinib achieve a complete cytogenetic remission (CCgR) and low levels of BCR-ABL transcripts. CCgR is durable in the majority of patients but relapse occurs in a subset.

EXPERIMENTAL DESIGN

To determine the potential of quantitative reverse transcription-PCR of BCR-ABL to predict cytogenetic relapse, we serially monitored residual disease in 97 CML patients with an imatinib-induced CCgR. Patients with late chronic phase CML after IFN-alpha failure were treated with imatinib (400 mg daily).

RESULTS

During the imatinib median follow-up time of 36 months (range, 12-54 months), disease monitoring occurred by cytogenetics and quantitative PCR. Twenty percent of patients experienced cytogenetic relapse at a median of 18 months after CCgR and a median of 24 months after starting imatinib. None of the possible prognostic factors studied in univariate and multivariate analyses seemed to predict for loss of cytogenetic response but the reduction of BCR-ABL transcript levels at the time of CCgR is an important prognostic factor.

CONCLUSIONS

In our study, we showed not only that achieving a major molecular remission at 12 months is predictive of a durable cytogenetic remission but also that patients who achieved a major molecular remission (expressed both as the BCR-ABL/beta2 microglobulin ratio % <0.0005 and as a 3-log reduction from median baseline value) already at the time of first achieving a CCgR have significantly longer cytogenetic remission durations than those without this magnitude of molecular response (P < 0.05).

Prediction of response to imatinib by prospective quantitation of BCR-ABL transcript in late chronic phase chronic myeloid leukemia patients

Imatinib mesylate (STI571), a specific Bcr-Abl inhibitor, has shown a potent antileukemic activity in clinical studies of chronic myeloid leukemia (CML) patients. Early prediction of response to imatinib cannot be anticipated. We used a standardized quantitative reverse-transcriptase polymerase chain reaction (QRT-PCR) for BCR-ABL transcripts on 191 out of 200 late-chronic phase CML patients enrolled in a phase II clinical trial with imatinib 400 mg/day. Bone marrow samples were collected before treatment, after 12, 20 and at the end of study treatment (52 weeks) while peripheral blood samples were obtained after 2, 3, 6, 10, 14, 20 and 52 weeks of therapy. The amount of BCR-ABL transcript was expressed as the ratio of BCR-ABL to beta2-microglobulin (beta2M). We show that, following initiation of imatinib, the early BCR-ABL level trends in both bone marrow and peripheral blood samples made it possible to predict the subsequent cytogenetic outcome and response. We propose this method as the method of choice for monitoring patients on imatinib therapy. QRT-PCR studies may be able to identify degrees of molecular response that predict both complete cytogenetic response and long term stability, as well as patterns of response that provide an early indication of relapse and imatinib resistance.

Outcome of four patients with chronic myeloid leukemia after imatinib mesylate discontinuation

Imatinib mesylate (IM) therapy is effective in patients with chronic myeloid leukemia (CML). However, whether it should be discontinued in patients who achieve sustained molecular response is debated. We describe 4 patients with undetectable levels of BCR-ABL transcripts in whom IM therapy was discontinued. Two patients relapsed after 7 and 10 months and promptly responded after restarting therapy; 2 patients are off therapy at the last follow-up visit after 14 and 15 months and are still in complete molecular remission.

TP53 codon 72 polymorphism in patients with chronic myeloid leukemia

A single nucleotide polymorphism at TP53 codon 72 means that two alleles exist: A1 (proline residue, Pro72) and A2 (arginine residue, Arg72). The Pro72 variant of p53 has a lower apoptotic potential. We found that allele A1 was more frequent in patients with chronic myeloid leukemia (CML) than in controls, and among CML patients who had no cytogenetic response than among responders.

Hypereosinophilic syndrome and cyclic oscillations in blood cell counts. A clonal disorder of hematopoiesis originating in a pluripotent stem cell

We studied a patient with hypereosinophilic syndrome (HES) who had myeloproliferative features, was unresponsive to imatinib mesylate, and showed cyclic oscillations in blood cell counts. No rearrangement in PDGFRA, PDGFRB and ETV6 genes was detected. Clonal analysis of hematopoiesis consistently showed skewed X-chromosome inactivation patterns in both granulocytes and T-lymphocytes, indicating a clonal myeloproliferative disorder originating in a pluripotent stem cell.

Muco-cutaneous changes during long-term therapy with hydroxyurea in chronic myeloid leukaemia

Hydroxyurea is an antimetabolite agent used in the treatment of myeloproliferative disorders and sickle cell anaemia. Although hydroxyurea is relatively well tolerated, adverse effects often involve skin and mucous membrane during long-term therapy. A group of 510 patients affected by chronic myeloid leukaemia from 1977 to 1998 has been considered. Only 158 patients were treated with hydroxyurea and fulfilled inclusion/exclusion criteria of this study. A spectrum of severe cutaneous and mucosal changes (inflammatory and neoplastic) was seen in about 13% of patients (21 patients out of 158) and was studied in detail. Cutaneous and mucosal atrophy were observed in all 21 patients. Skin atrophy was often characterized by numerous telangiectases, especially on legs and on sun-exposed sites (16/21). Cutaneous, mucosal and nail hyperpigmentation was evident, albeit with variable extent, in 10 of the 21 patients. Severe stomatitis and glossitis with flattening of papillae were another common finding. Five patients, who received a particularly long treatment with hydroxyurea, developed squamous-cell neoplasms on sun-exposed sites (both squamous-cell carcinomas and keratoacanthomas). Acral changes were characteristic and constant, including acral erythema (21/21), dermatomyositis-like changes on the dorsa of hands (7/21), ulcers localized on acral areas of legs, on genitalia and oral mucosae (20/21). The frequency and the variety of these muco-cutaneous changes are reported and the mechanisms by which hydroxyurea may induce this muco-cutaneous syndrome-like group of changes, are proposed.

Efficacy of pipobroman in the treatment of polycythemia vera: long-term results in 163 patients

BACKGROUND AND OBJECTIVES

Polycythemia vera (PV) is a myeloproliferative disorder, characterized by the expansion of the red cell mass. Our purpose was to evaluate the efficacy of pipobroman (PB) in the long-term control of PV and to assess early and late events.

DESIGN AND METHODS

From June 1975 to December 1997, 163 untreated patients with PV (median age 57 years, range 30-82) were treated with PB in a single Institute for a median follow-up of 120 months. The diagnosis was made according to the Polycythemia Vera Study Group criteria. PB was given at the dose of 1 mg/kg/day until hematologic response (hematocrit < 45% and platelets < 400x109/L) and of 0.3-0.6 mg/kg/day as maintenance therapy.

RESULTS

Hematologic remission was achieved in 94% of patients in a median time of 13 weeks (range 6-48). Median overall survival was 215 months, with a standardized mortality ratio of 1.7. The cumulative risk of death was 11%, 22%, and 26% at 7, 10, and 12 years, respectively. The incidence of thrombotic events was 18.4x105 person-year and the cumulative risk was 6%, 11%, 16%, and 20% at 3, 7, 10, and 12 years respectively. Acute leukemia occurred in 11 patients, myelofibrosis in 7, and solid tumors in 11. The 10-year cumulative risk of leukemia, myelofibrosis, and solid tumors was 5%, 4%, and 8%, respectively. In the logistic analysis age over 65 (p = 0.0001) and thrombotic events at diagnosis (p = 0.001) were significantly correlated with a higher risk of death. Female gender (p = 0.02) and age over 65 (p = 0.01) significantly influenced the occurrence of thrombotic complications. Age was the only significant risk factor for leukemia (p = 0.04) and for solid tumors (p = 0.03), while the duration of PB treatment did not influence these risks. No significant risk factor was demonstrated for myelofibrosis.

INTERPRETATION AND CONCLUSIONS

This study demonstrates in a large series of patients, observed for a long period, that pipobroman is effective in the long-term control of PV. The risk of early thrombotic complications at 3 years is 6% and the 10-year risk of acute leukemia, late myelofibrosis, and solid tumors is 5%, 4%, and 8%, respectively. The duration of pipobroman treatment did not correlate with these events.

Clinical and cytologic characteristics of blastic phase in Ph-positive chronic myeloid leukemia treated with alpha-interferon

We report 72 blastic crises (BC), occurring in 238 Ph+ chronic myeloid leukemia (CML) patients treated in chronic phase (CP) with alpha-interferon (IFN) for a median time of 51 months (range 7-96). The 238 patients were grouped by Sokal's risk at diagnosis in low- (LR), intermediate- (IR) and high-risk (HR), and by CP treatment. Group 1: 160 patients (57% LR, 31% IR, 12% HR) given IFN alone in early CP. Group 2: 31 patients (65% LR, 32% IR, 3% HR) given IFN alone in late CP. Group 3: 23 patients (78% LR, 22% IR) given IFN before and after autologous stem cell transplantation (ASCT). Group 4: 24 patients (83% LR, 17% IR) given IFN after ASCT. Of the 72 BC, 52 (72%) were myeloid (My), and 20 (28%) lymphoid (Ly). Overall BC incidence was similar in all CP treatment groups, although with a prevalence of Ly BC in groups 3 + 4 vs groups 1 + 2, (p = NS); the incidence of BC was higher in HR patients (P = NS), but on the whole it was lower than expected on the basis of historical controls. Lymphoid BC was more frequent in LR than in IR + HR patients (P < 0.05), and was more frequent in responders to IFN, than in non-responders (P < 0.05). In conclusion, a subset of patients with low risk at diagnosis, better response to IFN and proneness to evolve into Ly BC can be identified. The role played by IFN in this context remains to be defined.

Chronic myelogenous leukemia and exposure to ionizing radiation--a retrospective study of 443 patients

Exposure to ionizing radiations (Rx) has been implicated as a causative factor of chronic myelogenous leukemia (CML). We performed a retrospective study of 443 consecutive CML patients, looking for a history of significant exposure to Rx, and evaluated the clinical and hematological characteristics in order to find any difference between radiation-related CML patients and those with de novo CML. We identified 406 patients without known exposure to mutagens (group I) and 37 patients with prior significant exposure to Rx (group II). In comparison to patients of group I, those of group II showed particular clinical and hematological features: significantly lower incidence of bulky splenomegaly (p < 0.05) and hyperleukocytosis (WBC > 100 x 10(9)/l; p < 0.05); significantly higher incidence of anemia (Hb < 10 g/dl; p < 0.01). Patients with radiation-related CML had a significantly better survival than those with de novo CML (median survival 61 months vs 42 months; p < 0.05). In conclusion, this study of a large cohort of CML patients indicates that the subgroup of patients with a history of significant exposure to ionizing radiation has particular clinical and hematological features at onset (lower tumor burden, higher frequency of anemia) and a better survival.

Evolving modalities of treatment with interferon alfa-2b for Ph1-positive chronic myelogenous leukaemia

We have administered interferon alfa-2b, alone or in combination with chemotherapy, to 126 Ph1-positive chronic myelogenous leukaemia patients. Of 71 early chronic phase (CP) patients (less than 12 months from diagnosis), 41 (58%) obtained a complete haematological response (CHR). Daily interferon was more effective than intermittent administration. In previously untreated patients, the response was significantly influenced by risk status at diagnosis. Thirty-four out of 71 (48%) patients improved cytogenetically, the median of Ph1+ mitoses declining from 100% to 66% with complete Ph1-suppression in one case. Of 46 late CP patients (greater than 12 months from diagnosis), 32 (70%) achieved CHR with interferon alone or combined with chemotherapy. All 10 patients with disease well controlled by chemotherapy obtained stable CHR with interferon alone. Of 36 partial responders to conventional chemotherapy, 22 (61%) obtained CHR on interferon plus low-dose hydroxyurea. Ph1 mosaicism was reached by 16 (35%) late CP patients (median Ph1+ cells 75%). Of nine accelerated phase patients on interferon plus chemotherapy, one attained CHR, and two responded partially. At a median follow up of 36 months, of 41 CHR patients in early CP, 15 are controlled on interferon, 12 have had autologous bone marrow transplantation (BMT), and two allogeneic BMT. Blastic transformation (BT) has occurred in eight of 41 CHR patients (19%) versus 17 of 30 (57%) non-responders and partial responders to interferon. At a median follow up of 22 months, of 32 late CP patients obtaining CHR, 26 remain on interferon, one had allogeneic BMT, one had autologous BMT, and one developed BT (versus five out of 14 with less than CHR). These studies confirm the haematological and cytogenetic efficacy of interferon in CML and indicate that the disease status at the start of treatment is critical in determining the success of therapy.

Treatment of terminal-phase chronic myelogenous leukemia with intermediate-dose cytarabine and hydroxyurea

We used intermediate doses of Ara-C (IDAra-C) in the treatment of 15 patients with chronic myelogenous leukemia (CML) in blast crisis and, combined with hydroxyurea, in 20 CML patients in accelerated phase. Patients with blastic CML received intensive 5-day courses of IDAra-C 600 mg/m2 every 12 h as a 2-h infusion. Of 15 patients, three achieved complete response (CR) and three partial response (PR), for an overall response rate of 40 per cent. All patients developed severe leukopenia and thrombocytopenia, and two died in hypoplasia. Except nausea and vomiting requiring medication, other nonhematologic toxicities were uncommon. Median response duration was 4 months (range 1 to 7 months). Survival was 5 months for responders and 1.5 months for nonresponders. Patients with CML in accelerated phase were treated with two-day courses of IDAra-C 600 mg/m2 every 12 h by 2-h infusion, every two-three weeks. Daily hydroxyurea 1-1.5 g/day was administered between courses. Of 20 patients, 15 (75 per cent) achieved a good PR with rapid improvement of the symptoms of disease acceleration. The median duration of response was 11 months (range 3 to 38 months); duration was over 24 months in five patients. The median survival from the start of IDAra-C was 13 months for responders and 3.5 months for nonresponders. We conclude that IDAra-C is an effective approach for CML in terminal phase. Its use in 5-day induction courses for blast crisis CML has a response rate comparable to that achieved with high-dose Ara-C. In patients in accelerated phase, the combination of short courses of IDAra-C with hydroxyurea is a well-tolerated treatment able to improve substantially the clinical and hematologic symptoms of disease progression.

Extramedullary disease in Ph'-positive chronic myelogenous leukemia: frequency, clinical features and prognostic significance

Of 349 consecutive patients with Philadelphia-positive chronic myelogenous leukemia (Ph' + CML), 14 (4%) developed extramedullary disease (EMD) during their illness. The sites of EMD were: bone (57%), lymph nodes (29%), skin and soft tissues (21%), central nervous system (14%). The median time from diagnosis of CML to the occurrence of EMD was 48 months. At the time of diagnosis of EMD, 7 patients were hematologically in chronic phase, while 7 showed features of accelerated or blastic CML. For patients lacking medullary blastic transformation criteria, the median time from diagnosis of EMD to blast crisis was 4 months. The overall median survival from development of EMD was 5 months. In conclusion, EMD may occur during the course of CML either in the context of a frank blastic transformation, or as an isolated tumoral infiltrate which heralds an impending blast crisis. Its recognition requires a prompt change to acute-phase chemotherapy.

Mitoxantrone and etoposide: an effective regimen for refractory or relapsed acute myelogenous leukemia

23 adult patients with refractory or relapsed acute myelogenous leukemia (AML) received salvage chemotherapy with mitoxantrone and etoposide. The regimen consisted of mitoxantrone, 10 mg/m2/d by 30-min infusion, and etoposide 100 mg/m2/d by 30-min infusion, given 12 h apart for 5 consecutive d. Of 23 patients treated, 13 met the criteria for highly refractory disease (6 primary resistant; 4 with early relapse during maintenance; 3 relapsed and refractory to reinduction). 10 patients had relapsed off-therapy more than 6 months after achieving first CR. Overall, 14 patients (61%) achieved a complete remission (CR): 6/13 (46%) with refractory AML, and 8/10 (80%) with relapsed AML. 2 patients had a partial remission, 2 died in aplasia, and 5 were nonresponders. In responding patients, the median time for recovery of granulocyte count was 27 d. The most important nonhematologic side effect was oral mucositis, which was severe in 35% of cases. No signs of cardiac toxicity were observed. The median CR duration was 5 months (range, 2 to 12+ months). The combination of mitoxantrone and etoposide appears a highly effective and relatively well tolerated salvage regimen for refractory and relapsed AML. Its incorporation into first-line induction and consolidation programs for newly diagnosed AML patients should be considered.

Bone marrow and blood involvement by non-Hodgkin's lymphoma: a study of clinicopathologic correlations and prognostic significance in relationship to the Working Formulation

In a series of 172 patients with non-Hodgkin's lymphoma (NHL) classified according to the Working Formulation (WF) the overall incidence of bone marrow infiltration (BM+) at diagnosis was 39%: 59% for low-grade (LGML), 30% for intermediate-grade (IGML), and 25% for high-grade malignant lymphomas (HGML). The features most significantly correlated with the presence of BM+ were a low grade of histological malignancy, the degree of splenomegaly and high values of LDH, while those correlated with the extent of BM+ were a non-focal pattern of BM disease, the presence of blood involvement at diagnosis, and the degree of BM fibrosis. Blood involvement was detected at diagnosis in 13% of patients, and a further 16% developed a leukemic phase during the course of the disease. Blood involvement correlated significantly with splenomegaly, bulky disease, advanced clinical stage, and extent of BM+. The presence of BM infiltration 'per se' at diagnosis did not significantly affect prognosis. However, the extent of BM disease was correlated with a poorer outcome in IGML and HGML patients. Regarding peripheral blood involvement, in LGML patients only late leukemic conversions were significantly associated with a worse prognosis. In patients with IGML and HGML, either initial or subsequent blood involvement was correlated with significantly poorer outcome.

Combination chemotherapy with alternating MOPP-ABVD in advanced Hodgkin's disease

Fifty untreated adult patients with advanced Hodgkin's disease (HD) were given alternating MOPP-ABVD chemotherapy in a prospective eight-cycle program. This series included 33 patients with stage II-III disease and bulky lymphoma and/or B symptoms, and 17 patients with stage IV disease. Nodular sclerosis amounted to 52%, and systemic symptoms were present in 70% of patients. The median follow-up was 50 months from the initiation of therapy (range: 36-78 months). The complete remission rate was 80%, with no differences according to the main patient characteristics before therapy, except for bulky (65%) versus non bulky (88%) disease (p = 0.05). The actuarial 4-year overall (OS) and relapse-free survival were 78% and 71%, respectively. No clear-cut pretreatment characteristics showed an influence on survival, although there was a trend favoring non bulky versus bulky disease (p = 0.08). The actuarial 4-year OS of complete responders was 92%; all 13 patients who died had evidence of HD; the cause of death was disease progression and organ failure in 11 cases, acute myelomonocytic and opportunistic infections with AIDS in the other two cases, respectively. No severe pancytopenia episodes or life-threatening complications occurred during therapy; gastrointestinal and neurological toxicity were mild and no patient refused to complete the treatment. Menstruating women were given estrogen-progesterone combinations, and all continued to have regular menses throughout chemotherapy and afterwards; a young woman had a normal pregnancy resulting in a normal live birth. Only one case of stable amenorrhea was observed. Oligospermia after chemotherapy was seen in seven of 10 tested males, and azoospermia in one case.(ABSTRACT TRUNCATED AT 250 WORDS)

Hydroxyurea and 6-mercaptopurine in the treatment of chronic granulocytic leukemia

From 1975 to 1981, 92 patients with newly diagnosed Ph'-positive chronic granulocytic leukemia entered two consecutive studies. The initial trial (Study I, 1975-1978) tested the efficacy of hydroxyurea (HU) as single agent in 45 consecutive patients. In an effort to improve results obtained with HU alone, from 1978 to 1981, 47 new patients entered a second trial (Study II), which consisted of a continuous treatment with a combination of HU and 6-mercaptopurine (6-MP), at doses adjusted so as to maintain the leukocyte counts between 4 and 12 X 10(9)/L. The aim of this second study was to prolong the duration of chronic phase (CP) by the addition of 6-MP to HU and by a stricter continuous control of the size of the total granulocytic mass (TGM). Both regimens were well tolerated. Median duration of CP was 43 months in Study I and 41 months in Study II. Median survival was 51.5 months and 45 months respectively. These data indicate that neither the addition of 6-MP to HU alone, nor the effort to keep a smaller TGM, play a substantial role in postponement of blastic transformation in CGL.

Efficacy trial of pipobroman in essential thrombocythemia: a study of 24 patients

Pipobroman (PB) was tested in a prospective efficacy trial in 24 previously untreated patients with essential thrombocythemia and followed up for a median of 47 months (range, 12-120). Plateletpheresis was not done. Hematologic complete response (platelet count less than 450 X 10(9)/L for 3 consecutive months) was achieved in 92% of the cases, in a median time of 12 weeks (range, 2-22). However, continuous low-dose maintenance therapy with PB was necessary to avoid recurrences of the disease. Major thrombocythemia-related complications were observed in 20% of the cases; the 5-year overall and complication-free survival rates were 92% and 75%, respectively. No acute or chronic toxicity was observed; no drug-induced amenorrhea and subsequent acute leukemia occurred. PB does appear to be efficacious in essential thrombocythemia; however, the evaluation of its leukemogenic risk will await further experience.