Combination therapy with arsenic trioxide (ATO), all-trans retinoic acid (ATRA), and gemtuzumab ozogamycin (GO) in relapsed acute promyelocytic leukemia (APL)

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Background: Relapse occurs in 20 to 30% of patients with APL treated with ATRA. ATO is an effective agent for salvage of APL relapse, and GO has shown activity in APL due to the high expression of CD33. Methods: We investigated the efficacy of a combination regimen of ATO, ATRA and mylotarg in 8 patients with APL in 1st relapse. All patients had been previously treated with regimens that included ATRA and chemotherapy. Patients received ATO 0.15 mg/kg intravenously until marrow complete remission (CR). Once in marrow CR patient was observed until CR. Once CR was achieved or 60 days from the start of induction therapy, consolidation therapy was initiated with 1) ATO 0.15 mg/kg intravenously for 5 days per week for 4 weeks, repeated every 8 weeks for total of 5 courses, 2) ATRA 45mg/m2 orally twice daily 10 days per month for 10 months, and 3) GO 9 mg/m2 intravenously monthly for 10 months. Patients then received maintenance with 1) idarubicin 8mg/m2daily on day 1 and 2 every month for 3 months, 2) ATRA 45mg/m2orally daily 10 days per month for 14 months, 3) 6-MP 50 mg orally 3 times per day for 11 months and methotrexate 15mg/m2 orally once a week for 11 months. Results: The median age is 51years (range, 18–68 years), median WBC count 1.9 ×109/L (range 0.9–7.7 ×109/L), platelets 71 ×109/L (range, 6–164 ×109/L). The median duration of 1st CR was 7 months (range, 3 to 17 months). Seven patients achieved CR with median time to remission of 8 weeks (range 3–15 weeks). One patient achieved marrow CR after 3 weeks of therapy but is too early to evaluate for CR. All 7 are still in CR after a median follow up of 36+ months (range, 1+ to 51+ months). All seven patients achieved molecular remission. All patients had myelosuppression but there was no grade 3–4 extramedullary toxicity. Two patients died, one died secondary to complication related to metastatic lung adenocarcinoma, and the other patient died of sepsis. Conclusions: We concluded that the combination of ATO, ATRA and mylotarg is effective and may achieve durable remissions in many patients with APL in first relapse. It should be considered as an effective alternative to allogeneic or autologous transplant.

No significant financial relationships to disclose.

More cell death in refractory anemia with excess blasts in transformation than in acute myeloid leukemia

Refractory anemia with excess blasts in transformation (RAEB-T) is a subgroup of myelodysplastic syndrome (MDS) in which the bone marrow blast count ranges from 20% to 30%. The recently proposed World Health Organization Classification of Hematologic Malignancies eliminated this category from MDS by lowering the blast count cutoff for acute myeloid leukemia (AML) from 30% to 20%. However, MDS is distinguished from AML by a significant increase in apoptosis. To investigate the difference in apoptosis between RAEB-T, AML, and other categories of MDS, we prospectively analyzed fresh bone marrow samples using the Annexin V and mitochondrial potential assays. There was a significantly higher level of apoptosis in RAEB-T than in AML according to both assays, while no significant differences between RAEB-T and other categories of MDS were noted. The data suggest that RAEB-T is more likely to be an advanced stage of MDS and biologically different from AML.

Significance of angiogenin plasma concentrations in patients with acute myeloid leukaemia and advanced myelodysplastic syndrome

Human angiogenin is a potent inducer of angiogenesis. The association between angiogenin and cancer progression and poor outcome in solid tumours has been documented, but its significance in leukaemias has not been evaluated. We evaluated plasma angiogenin levels in 101 previously untreated patients with acute myeloid leukaemia (AML) (59 patients) and advanced myelodysplastic syndrome (MDS) (42 patients). Angiogenin levels were significantly higher in AML and advanced MDS patients than in healthy individuals (P < 0.00001). Angiogenin levels were also significantly higher in advanced MDS than in AML (P = 0.001). Higher levels of angiogenin correlated with prolonged survival periods in both AML and advanced MDS patients (P = 0.02 and 0.01 respectively). We found no correlation between angiogenin plasma level and various patient characteristics, including age, performance status, antecedent haematological disorder, haemoglobin, white blood cell and platelet counts, and poor prognosis cytogenetics. There was no significant correlation between angiogenin level and complete remission rate and duration in AML or advanced MDS patients. In multivariate analysis, angiogenin concentration retained its significance as a prognostic factor in AML (P = 0.03), together with age (P = 0.00007) and haemoglobin (P = 0.03).

Plasma hepatocyte growth factor is a prognostic factor in patients with acute myeloid leukemia but not in patients with myelodysplastic syndrome

Hepatocyte growth factor (HGF) is a potent angiogenic factor. The aim of our study was to evaluate plasma HGF levels and their prognostic significance in patients with newly diagnosed acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). The sandwich enzyme immunoassay technique was used to quantify HGF in stored samples obtained before treatment from patients with AML (59 patients) and MDS (42 patients) treated at The University of Texas MD Anderson Cancer Center. HGF levels were significantly higher in patients with AML or MDS than in healthy individuals (P < 0.0001). Higher HGF levels in both AML and MDS correlated significantly with white blood cell (P = 0.000001 for both groups) and monocyte counts (P = 0.0004 and 0.003, respectively), and with poor performance status (P = 0.03 and 0.001, respectively). Using Cox proportional hazard model and HGF levels as a continuous variable, plasma levels of HGF correlated with shorter survival of AML (P = 0.001), but not MDS (P = 0.34) patients. No significant correlation was observed between HGF levels and complete remission rate or duration. In the multivariate analysis HGF retained its significance as prognostic factor in AML (P = 0.02), along with age (P = 0.0005).

Treatment of newly-diagnosed acute promyelocytic leukemia with liposomal all-trans retinoic acid

It has been postulated that recurrence of disease in some patients with newly-diagnosed APL induced into CR, and subsequently maintained, with single agent oral ATRA results from the decline in ATRA levels that occurs with repeated dosing. Administration of liposomal ATRA (lipoATRA) circumvents, for perhaps several months, the decrease in ATRA levels and produces CRs in patients with relapsed APL. These findings led us to administer lipoATRA "monotherapy" to patients with newly-diagnosed APL. Patients received lipoATRA (90 mg/m2) for induction and continued to receive the drug, by itself, for 9 months unless 2 PCR tests done within 2-4 weeks of each other at a sensitivity level of 10(-4) were positive at 3 or 6 months from CR date, in which case idarubicin was added to lipoATRA. If the PCR test was negative 9 months from CR date, treatment stopped. 34 patients were enrolled, of whom 79% entered CR. The PCR test at time of CR was positive in 23/24 patients, but was negative in 24/26 (92%) 3 months later. Of most interest 11 of the 26 evaluable responding patients have remained PCR negative (tested Q 3 months) with a median follow-up of 18 months (range up to 34 months). It is generally believed that this type of result would be unlikely with oral ATRA monotherapy. Recurrence of morphologic APL has occurred in 4 patients, at 5, 6, 12, and 12 months, with a median follow-up time of 18 months in the patients remaining alive in CR. Comparison of this lipoATRA +/- idarubicin trial with oral ATRA + idarubicin induction and idarubicin + POMP maintenance, our previous trial, indicates similar survival, CR, and DFS in CR rates, with a suggestion that lipoATRA may produce lower CR rates and hence shorter survival in patients with high-risk disease (wbc count > 10,000/microliter. Nonetheless, the rates and duration of PCR negativity produced by lipoATRA monotherapy suggest that lipoATRA is a superior anti-APL agent than oral ATRA.

BCR rearrangement-negative chronic myelogenous leukemia revisited

PURPOSE

To document the characteristics of patients with major breakpoint cluster region (M-bcr) rearrangement-negative chronic myelogenous leukemia (CML).

PATIENTS AND METHODS

The hematopathologist, who was blinded to patients' molecular status, reviewed the referral bone marrows and peripheral-blood smears from 26 patients with Philadelphia (Ph) translocation-negative CML who lacked Bcr rearrangement (and other evidence of a Bcr-Abl anomaly) and 14 patients (controls) with chronic-phase Ph-positive CML. Clinical data was ascertained by chart review.

RESULTS

Among the 26 M-bcr rearrangement-negative CML patients, three pathologic subtypes emerged: (1) patients indistinguishable from classic CML (n = 9), (2) patients with atypical CML (n = 8), and (3) patients with chronic neutrophilic leukemia (n = 9). Among the 14 patients with Ph-positive CML who were included in the blinded review, 13 were classified as classic CML, and one was classified as atypical CML. The only statistically significant difference between M-bcr rearrangement-negative subgroups was in the proportion of patients having karyotypic abnormalities, an observation common only in patients with atypical CML (P = 0.008). However, the small number of patients in each subgroup limited our ability to differentiate between them. Interferon alfa induced complete hematologic remission in five of 14 patients; four of these remissions lasted more than 5 years. Only one of 26 patients developed blast crisis. The median survival of the 26 patients was 37 months.

CONCLUSION

Patients with M-bcr rearrangement-negative CML fall into three morphologic subgroups. Disease evolution does not generally involve blastic transformation. Instead, patients show progressive organomegaly, leukocytosis, anemia, and thrombocytosis. Some patients in each subgroup can respond to interferon alfa.

Angiogenesis in acute and chronic leukemias and myelodysplastic syndromes

Angiogenesis has been associated with the growth, dissemination, and metastasis of solid tumors. The aims of this study were to evaluate the vascularity and the levels of angiogenic factors in patients with acute and chronic leukemias and myelodysplastic syndromes (MDS). The numbers of blood vessels were measured in 145 bone marrow biopsies and the levels of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), tumor necrosis growth factor-alpha (TNF-alpha), tumor growth factor-alpha (TGF-alpha), and hepatocyte growth factor (HGF) were determined in 417 plasma samples. Except for chronic lymphocytic leukemia (CLL), vascularity was significantly higher in all leukemias and MDS compared with control bone marrows. The highest number of blood vessels and largest vascular area were found in chronic myeloid leukemia (CML). VEGF, bFGF, and HGF plasma levels were significantly increased in acute myeloid leukemia (AML), CML, CLL, chronic myelomonocytic leukemia (CMML), and MDS. HGF, TNF-alpha, and bFGF but not VEGF were significantly increased in acute lymphoblastic leukemia (ALL). TNF-alpha levels were significantly increased in all diseases except for AML and MDS. No significant increase was found in TGF-alpha in any leukemia or MDS. The highest plasma levels of VEGF were in CML, and the highest plasma levels of bFGF were in CLL. The levels of HGF were highest in CMML. These data suggest that vascularity and angiogenic factors are increased in leukemias and MDS and may play a role in the leukemogenic process.

Variations in the low levels of cyclin D1/BCL1 have prognostic value in chronic lymphocytic leukemia

Cyclin D1 (CyD1)/BCL1 (PRAD1) is expressed at high levels in almost all cases of mantle cell leukemia/lymphoma (MCL) and in rare cases of chronic lymphocytic leukemia (CLL). The CyD1/BCL1 protein plays an important role in the progression of cells through the G1 phase of cell cycle. Most of the CyD1/BCL1 protein expression studies are performed using immunohistochemistry. We used a sensitive solid-phase radioimmunoassay (RIA) to quantify CyD1 protein expression in 199 patients with CLL. Of these 137 patients were previously untreated with the rest having had standard chemotherapeutic regimens including alkylating agents and fludarabine before being referred to our center. Median white cell count in these patients was 49x10(3) /microl (range 3.0-438.5x10(3)/microl), hemoglobin level 13.1 g/dl (range 5.2-17.3 g/dl), platelet count 157x10(3) /microl (range 10-377x10(3) /microl), age 58 (range 26-89), and beta2-microglobulin 2.75 mg/dl (range 1.1-14.3). The median radioactivity (CPM) of mononuclear cells obtained from 56 normal individuals was assigned a value of 1. There was no significant variation in CyD1 levels among normal individuals (SD=0. 12). While most CyD1 levels in MCL varied from 6.5 to 15.6, the median CyD1/BCL1 in CLL was 1.4 with 75th percentile under 2.12. Rare CLL cases (3.5%) showed levels between 4 and 8.83. When divided into two groups at the median level, patients with higher CyD1/BCL1 expression had shorter survival (P = 0.03). This remained true when applied only to the previously untreated patients (P=0.05). Despite the relatively low expression, the CyD1/BCL1 levels in univariate analysis were as good or better predictors of survival than Binet (P = 0.03) or Rai (P = 0.05) staging. Furthermore, CyD1/BCL1 levels correlated with serum beta2-microglobulin (P = 0.001), white blood cell count (P = 0.004) and hemoglobin levels at the time of collection (P = 0.0003) but not with lymphocyte count, platelet count or age. The data demonstrate that CyD1/BCL1 is likely to play a significant role in the biology of CLL and can be used as a prognostic indicator. Further studies to clarify the role of CyD1 in the biology of CLL and its value as a prognostic indicator at the time of diagnosis are encouraged.

Deletions in the 13q14 locus in adult lymphoblastic leukemia: rate of incidence and relevance

BACKGROUND

A putative tumor suppressor gene involved in chronic lymphocytic leukemia (CLL) has been localized to the 13q14 locus. Microsatellite analysis was used to test whether this locus also is involved in acute lymphoblastic leukemia (ALL) and its prognostic relevance determined.

METHODS

The authors analyzed 49 patients with adult ALL for deletions at the 13q14 locus using a battery of 6 microsatellite markers corresponding to this region (D13S260, STR257, D13S263, D13S153, D13S319, and AFMa301wb5).

RESULTS

Five of the 49 adult ALL patients analyzed (10%) showed loss of heterozygosity (LOH) or deletions at 13q14. Similar to CLL, the significant minimal deletions appeared to be localized between D13S260 and AFMa301wb5 and did not involve the retinoblastoma or BRCA2 genes. Among newly diagnosed patients, LOH was associated with shorter survival (P = 0.007).

CONCLUSIONS

These data suggest that the 13q14 gene, commonly deleted in CLL patients, also is deleted in some patients with adult ALL. Although the number of the cases in the current study is small, 13q deletions in ALL patients may play a role in the clinical behavior of this disease.

ATM gene deletion in patients with adult acute lymphoblastic leukemia

BACKGROUND

Loss of heterozygosity (LOH) at the ATM gene (mutated in ataxia telangiectasia [AT] patients) and ATM protein deficiency occur in 14% and 34%, respectively, of patients with chronic lymphocytic leukemia (CLL). ATM protein deficiency also is associated with aggressive disease and worse patient survival. Considering the aberrations in the ATM gene in CLL and the high rate of incidence of lymphoid neoplasias in AT patients, the authors investigated its incidence rate and significance in patients with adult acute lymphoblastic leukemia (ALL).

METHODS

Samples from 36 adults with ALL were analyzed for LOH and homozygous deletion (HD) using a panel of three microsatellite markers located at the ATM gene (D11S2179), the MLL gene (D11S1356), and the BCL1 gene (D11S987) loci. These markers are located within the 11q13-q23 locus.

RESULTS

Of the 36 informative cases, 10 (28%) showed deletions (7 LOH and 3 HDs) at the D11S2179 marker. In two patients, the deletions were extended to the MLL gene locus. These deletions were submicroscopic because only 3% (1 of 36) of patients showed abnormalities involving 11q23 using cytogenetic studies. The authors also estimated the levels of ATM protein in 15 ALL patients and 12 healthy volunteers by radioimmunoassay. The ATM protein levels in cases with LOH at the ATM gene were between 15-50% of those from normal bone marrow. In contrast to CLL patients, patients with LOH or HD at the ATM gene locus showed better survival compared with patients without ATM gene deletions (P = 0.003).

CONCLUSIONS

LOH of the ATM gene and protein deficiency are common in adult ALL, are not demonstrated at the cytogenetic level, and are associated with a favorable prognosis. The authors speculate that ATM deficiency may increase the sensitivity of leukemic blasts to the chemotherapy used during induction and after disease remission in patients with adult ALL. The relatively high frequency of deletion of the D11S2179 marker compared with the D11S1356 marker suggests that ATM is the target gene of the deletion at the 11q23 locus, and that such deletions may play a role in the pathogenesis of ALL.

Terminal deoxynucleotidyl transferase-negative acute lymphoblastic leukemia

OBJECTIVE

Terminal deoxynucleotidyl transferase (TdT) is a useful marker in the diagnosis of acute lymphoblastic leukemia (ALL) (French-American-British [FAB] L1 and L2) and is most useful in distinguishing ALL from mature B-lymphoid neoplasms, such as Burkitt lymphoma (FAB L3) and other lymphoid malignancies. The frequency of TdT-negative ALL is not known. Here we report 3 TdT-negative ALL cases that met the criteria for T-cell ALL.

DESIGN

We reviewed approximately 200 cases of ALL retrieved from the database at our institution. All cases were evaluated using Wright-Giemsa, myeloperoxidase, butyrate, and TdT staining; immunophenotyped using flow cytometry; and studied using Southern blot analyses for T-cell receptors and immunoglobulin gene rearrangement.

RESULTS

All ALL cases (L1 and L2) were TdT-positive, except for 3 cases that were of early T-cell lineage. None of the 3 cases demonstrated positivity for TdT in immunofluorescence staining with polyclonal antibodies or flow cytometry with monoclonal antibodies. Flow cytometric analysis confirmed a pre-T-cell immunophenotype in all 3 cases. One of the cases showed rearrangement of a T-cell antigen receptor and immunoglobulin heavy chain (J(H)). A second case showed germline configuration of T-cell receptors, but also showed rearrangement of the J(H), despite the expression of T-cell markers only.

The prognostic significance of 13q14 deletions in chronic lymphocytic leukemia

Although chronic lymphocytic leukemia (CLL) is the most common leukemia in adults, little is known about the molecular abnormalities underlying it and their prognostic significance. Using a battery of six microsatellite markers from 13q12.3-14.3 between BRACA2 gene and the Rb gene, we assayed loss of heterozygosity (LOH) in 78 CLL patients. We found deletion in 13q14 in 29 patients (37%) between D13S153 and the AFMa 301wb5. Classical cytogenetics was less sensitive, as it detected the 13q14 deletion in only one out of 69 patients (1%) in whom adequate metaphases were obtained. We found no significant difference in survival between patients with and patients without 13q14 LOH. In subset of patients with low beta2-microglobulin levels, those with 13q14 LOH had significantly shorter survival than did patients with low beta2-microglobulin levels but no 13q14 LOH. Also patients in early Rai stages (0-II) with 13q14 LOH had shorter survival period (P = 0.05) than did patients without LOH. These data confirm the prevalence of 13q14 deletion in CLL and suggest that this deletion may help identify more aggressive disease in patients presenting with early stage disease.

Sequential homoharringtonine and interferon-alpha in the treatment of early chronic phase chronic myelogenous leukemia

Homoharringtonine (HHT) is a novel plant alkaloid that produced a complete hematologic remission (CHR) in 72% of patients with late chronic phase chronic myelogenous leukemia (CML). Cytogenetic (CG) remissions were noted in 31%. In this study, six courses of HHT were administered to 90 patients with early chronic phase CML (< 1 year from diagnosis). Patients then received interferon-alpha (IFN-alpha) with a target dose of 5 MU/m2 daily. Results were compared with those in a prior group of patients treated with IFN-alpha-based therapy between 1982 and 1990. Ninety-two percent of patients achieved CHR with HHT; CG responses were observed in 60% and were major in 27%. Both CHR and CG response rates were significantly higher than those seen in historical control patients after 6 months of IFN-alpha therapy. After receiving HHT, patients required lower doses of IFN-alpha to maintain a CHR. The median dose delivered was 2.4 MU/m2. This reduction in IFN-alpha dose was associated with a lower incidence of myalgia and gastrointestinal (GI) disturbances than that seen in patients treated at the 5 MU/m2 dose. Overall, CG responses were seen in 66% of the patients who received HHT and IFN-alpha compared with 61% of the historical control patients. HHT is a very effective treatment of early chronic phase CML, and ongoing trials are investigating the simultaneous administration of HHT and IFN-alpha, as well as that of HHT and low-dose cytosine arabinoside in patients failing IFN-alpha therapy.

Randomized phase II study of fludarabine + cytosine arabinoside + idarubicin +/- all-trans retinoic acid +/- granulocyte colony-stimulating factor in poor prognosis newly diagnosed acute myeloid leukemia and myelodysplastic syndrome

Preclinical data suggest that retinoids, eg, all-trans retinoic acid (ATRA), lower concentrations of antiapoptotic proteins such as bcl-2, possibly thereby improving the outcome of anti-acute myeloid leukemia (AML) chemotherapy. Granulocyte colony-stimulating factor (G-CSF) has been considered to be potentially synergistic with ATRA in this regard. Accordingly, we randomized 215 patients with newly diagnosed AML (153 patients) or high-risk myelodysplastic syndrome (MDS) (refractory anemia with excess blasts [RAEB] or RAEB-t, 62 patients) to receive fludarabine + ara-C + idarubicin (FAI) alone, FAI + ATRA, FAI + G-CSF, or FAI + ATRA + G-CSF. Eligibility required one of the following: age over 71 years, a history of abnormal blood counts before M.D. Anderson (MDA) presentation, secondary AML/MDS, failure to respond to one prior course of chemotherapy given outside MDA, or abnormal renal or hepatic function. For the two treatment arms containing ATRA, ATRA was given 2 days (day-2) before beginning and continued for 3 days after completion of FAI. For the two treatment arms including G-CSF, G-CSF began on day-1 and continued until neutrophil recovery. Patients with white blood cell (WBC) counts >50,000/microL began ATRA on day 1 and G-CSF on day 2. Events (death, failure to achieve complete remission [CR], or relapse from CR) have occurred in 77% of the 215 patients. Reflecting the poor prognosis of the patients entered, the CR rate was only 51%, median event-free survival (EFS) time once in CR was 36 weeks, and median survival time was 28 weeks. A Cox regression analysis indicated that, after accounting for patient prognostic variables, none of the three adjuvant treatment combinations (FAI + ATRA, FAI + G, FAI + ATRA + G) affected survival, EFS, or EFS once in CR compared with FAI. Similarly, there were no significant effects of either ATRA ignoring G-CSF, or of G-CSF ignoring ATRA. As previously found, a diagnosis of RAEB or RAEB-t rather than AML was insignificant. There were no indications that the effect of ATRA differed according to cytogenetic group, diagnosis (AML or MDS), or treatment schedule. Logistic regression analysis indicated that, after accounting for prognosis, addition of G-CSF +/- ATRA to FAI improved CR rate versus either FAI or FAI + ATRA, but G-CSF had no effect on the other outcomes. We conclude that addition of ATRA +/- G-CSF to FAI had no effect on CR rate, survival, EFS, or EFS in CR in poor prognosis, newly diagnosed AML or high-risk MDS.

Deficiency of the ATM protein expression defines an aggressive subgroup of B-cell chronic lymphocytic leukemia

The gene mutated in ataxia telangiectasia, ATM, on human chromosome 11q22-q23 is implicated in cell cycle control and DNA repair. Ataxia telangiectasia patients as well as ATM-deficient mice are immune deficient and develop lymphoproliferative disease. Abnormalities in 11q22.3-q23.1 have also been described in B-cell chronic lymphocytic leukemia (B-CLL). We analyzed B-CLL samples for loss of heterozygosity (LOH) using microsatellite markers located at the ATM (D11S2179), mixed-lineage leukemia (MLL; D11S1356), and BCL1 (D11S987) loci, all of which are located around 11q23. Five (14%) of 36 informative cases showed LOH at the ATM gene, and two of these five cases had LOH at the MLL gene. No LOH was detected at the BCL1 locus, and none of the cases showed LOH at the MLL gene without LOH at the ATM gene. Four of these five cases with LOH at the ATM gene were studied for ATM protein expression by Western blot analysis. All four cases lacked ATM protein. An additional 111 cases of B-CLL were studied for expression of ATM protein by Western blot analysis and RIA. Thirty-eight (34%) of these cases showed ATM levels <50% of that seen in normal lymphoid cells. No morphological or immunophenotypic difference was observed between ATM-deficient B-CLL cases and cases with normal ATM expression. However, patients with ATM deficiency had significantly shorter survival times (35.66 versus 97.3 months; P = 0.003) and more aggressive disease, suggesting that ATM is involved in the leukemogenesis of B-CLL. These data also suggest that the ATM gene may play a role in the reported 11q23 abnormality in B-CLL, which also characterizes an aggressive disease.

Implications of potential cure in acute myelogenous leukemia: development of subsequent cancer and return to work

Chemotherapy produces extended remissions, and potential cures, in a small minority of patients with acute myeloid leukemia (AML). We explored whether potentially cured patients were at increased risk of subsequent invasive cancer and were able to return to work. Potentially cured patients were defined as those in first or second complete remission (CR) for at least 3 years based on hazard rates for recurrence or death in CR, which declined sharply after this time. Patients who received allogeneic marrow transplant were excluded. We used questionnaires, phone contact, and chart review to obtain information about subsequent cancer and work status. The number of patients who developed invasive cancer was compared with the number expected based on age, gender, and years of follow-up using the Connecticut Tumor Registry. A total of 215 patients met our criteria for potential cure: 203 in first CR and 12 in second CR (of 1,663 treated between 1965 and December, 1992). At a median of 9.2 years from first or second CR, 163 (76%) remain alive in CR. Fifteen patients developed 18 invasive cancers (expected number of patients, 8.8; observed/expected, 1.70; 95% CI, 0.96 to 2.84; P = . 06). Patients initially treated between 1973 to 1979, patients above the potentially cured cohort's median age of 40 years, and those who presented with abnormalities of chromosomes 5 and/or 7 were more likely to develop subsequent cancer, whereas the observed/expected ratio for younger patients was 1.05 (95% CI, 0.13 to 3.80; P = .56). Seventy-four percent of the patients who were working full-time and who were under age 50 at time of treatment for AML have been working full-time in the last 6 months. Only 17 of 56 patients who are currently not working cited physical limitation as the reason. Patients with potentially cured AML are likely to be able to return to work, and at least if younger do not, on average, have an increased risk of invasive cancer.

Detection of minimal residual disease by polymerase chain reaction of bcr/abl transcripts in chronic myelogenous leukaemia following allogeneic bone marrow transplantation

The prognostic significance of detecting minimal residual disease by polymerase chain reaction (PCR) amplification of bcr/abl mRNA transcripts was investigated in 27 bone marrow samples from 20 patients with Philadelphia chromosome (Ph1) positive chronic myelogenous leukaemia (CML) in complete cytogenetic remission following allogeneic bone marrow transplantation. Sixteen were transplanted in first chronic phase, two were in second chronic phase, one was in accelerated phase and one was in blast crisis. All 20 achieved complete cytogenetic remission post transplant and 15 patients had detectable bcr/abl mRNA by PCR from 2 to 22 months following the procedure. One of these patients had graft failure and one died from graft-versus-host-disease at 7 months. Of the remaining 13 PCR-positive patients, only one (8%) relapsed after 23 months; the other 12 were alive and still in remission after a median follow-up of 16+ months (ranging 5+ to 29+ months). Five patients were PCR negative; all are alive in complete clinical and cytogenetic remission at 10+, 11+, 19+, 25+ and 25+ months post transplant. In this study, detection of subclinical Ph1-positive cells by PCR was not associated with imminent clinical or cytogenetic relapse. Since late recurrence may potentially occur, long-term follow-up is required to definitely determine the prognostic value of the PCR assay.

CI-973, a new platinum derivative with potential antileukemic activity

We examined the effects of CI-973 (supplied by Parke-Davis) on several human leukemia cell lines and a Chinese hamster ovary (CHO) line and their drug-resistant counterparts. The cell lines used were HL-60, HL-60/mAMSA, HL-60/DOX, KBM3, KBM3/mAMSA 6, KBM3/mAMSA 6(85), CHO, and CHO/AC-7. DOX, mAMSA, and AC-7 indicate resistance to doxorubicin, amsacrine, or 1-beta-D-arabinofuranosylcytosine, respectively. Cells were incubated with CI-973, and the effect was evaluated by two methods: growth inhibition assay and inhibition of colony formation. All cell lines examined were inhibited by CI-973; two of three amsacrine-resistant lines and the one cytarabine-resistant line demonstrated collateral sensitivity. At equivalent dosages, a 4-day exposure provided much greater cell kill than a 1-h exposure. Clonogenic assay showed exponential killing over 3 log units. Maximum CI-973 levels required to kill 50% of cells were 10-fold lower than the peak plasma levels achieved in a phase I solid tumor study. A continuous infusion phase I study in acute leukemia has been initiated.

Molecular heterogeneity in acute leukemia lineage switch

Six cases of acute leukemia that underwent lineage switch from acute lymphocytic leukemia to acute myelogenous leukemia are reported. The mean age of the patients was 24 years, time to conversion was 36 months, and survival after conversion was only 3 months. Of the three cases which showed abnormal metaphases at both diagnosis and conversion, two (cases 2, 5) showed related cytogenetic abnormalities, and the third showed (case 3) independent chromosomal changes. Molecular analysis for immunoglobulin heavy chain and T-cell receptor beta chain genes showed that five of the six cases had rearrangement of at least one of these lymphoid associated genes at conversion to acute myelogenous leukemia. The single case (case 3) in which there were no lymphoid gene rearrangements at conversion was also the only case in which independent karyotypic abnormalities at diagnosis and conversion were demonstrated. Our findings suggest that lineage switch can represent either relapse of the original clone with heterogeneity at the molecular level or the emergence of a second new leukemic clone without molecular heterogeneity.

Suppression of c-myc and c-myb expression in myeloid cell lines treated with recombinant tumor necrosis factor-alpha

Proto-oncogenes are thought to be involved in cellular differentiation and proliferation. Tumor necrosis factors (TNFs) are specific cytokines that have cytostatic and cytotoxic effects in vitro against a wide range of human tumor cells. We have previously demonstrated that recombinant TNFs (rTNFs) have an antiproliferative effect on certain human leukemic cell lines (HL-60, KBM3, KBM5) and no effect on others (K562). To study the possible role of the c-myc and c-myb oncogenes in this antiproliferative effect of TNF, we examined their expression in cell lines HL-60, KBM3, KBM5, and K562 before and after incubation with rTNF-alpha. Expression of c-myc and c-myb was elevated in all cell lines prior to incubation with rTNF-alpha. In the sensitive cell lines HL-60, KBM5, and KBM3 expression of c-myc and c-myb decreased rapidly 8-, 16-, and 4-fold, respectively, by 24 hr. K562 cells, insensitive to rTNF-alpha, exhibited no change in c-myc or c-myb expression over 24 hr. These studies demonstrated that down-regulation of c-myc and c-myb expression were associated with antiproliferative effects of rTNF-alpha on these cell lines.

Immunofluorescence studies on proteins B23 and C23 in nucleoli of human lymphocytes

Nucleoli of normal and leukemic lymphocytes were studied by cytochemical and immunofluorescence methods to provide more information on the nucleolar presence and distribution of proteins B23 and C23. Annular nucleoli of human lymphocytes represent a very convenient subject for such studies, since they consist of one centrally located large fibrillar center surrounded by RNP components. In such nucleoli, protein C23 was present mainly in the central nucleolar region and protein B23 was found mostly in the periphery. The nucleolar area immunostained for protein B23 was usually larger than that stained for protein C23. The distribution of protein C23 appeared to be similar to that of intensely stained nucleolar argyrophilic components. No substantial differences were found between the distribution of proteins B23 and C23 in nucleoli of normal and leukemic lymphocytes. In lymphocytes of patients treated with chemotherapy, the immunofluorescence was diminished for protein B23 and particularly so for protein C23.