Cell wall composition and virulence in Escherichia coli.

Uridine diphosphate galactose 4-epimerase and phosphomannose isomerase-deficient mutants of Escherichia coli O111:B4 were studied to test the hypothesis that in E. coli a specific relationship exists between O antigenicity, virulence, and capacity to resist phagocytosis. The first mutant, designated J-5, produces a cell wall lipopolysaccharide, the side chains of which do not contain galactose, glucose, N-acetylglucosamine, or colitose. The second mutant produces a cell wall lipopolysaccharide which lacks only colitose. The capacity of these various organisms to kill mice was strikingly different. E. coli O111 was 1000 times as virulent as J-5, and 100 times as virulent as L-2. The capacity of the organisms to kill mice was correlated with their ability to resist phagocytosis and to persist in the peritoneal cavity. The parent strain of O111 resisted phagocytosis by macrophages in vivo and polymorphonuclear leukocytes in vitro. The mutants did not, and the organism most deficient in the saccharide component of its LPS was most susceptible to phagocytosis and least virulent. These results were corroborated by growing the mutants in appropriately supplemented media which permitted the synthesis of complete LPS, reversed the susceptibility to phagocytosis, and restored virulence. Finally, serological reactivity was consistent with previous observations which had demonstrated that the O antigenicity of E. coli is determined by the saccharide composition of its cell wall lipopolysaccharide. Despite the difference in the capacity of the various log-phase organisms to kill mice when injected intraperitoneally, purified lipopolysaccharides extracted from them did not differ significantly in their capacity to kill or produce fever. Thus virulence was shown to be independent of endotoxin activity which in turn seemed to be unrelated to the saccharide composition of the cell wall LPS. Collectively, these data provide at least a partial molecular definition of virulence in E. coli by demonstrating that the presence or absence of specific sugars in its cell wall lipopolysaccharide is a determinant of its antiphagocytic capacity and its virulence.

Myeloablative therapy with autologous stem cell rescue for patients with Ewing sarcoma.

The aim of this study was to identify risk factors associated with PFS in patients with Ewing sarcoma undergoing ASCT; 116 patients underwent ASCT in 1989-2000 and reported to the Center for International Blood and Marrow Transplant Research. Eighty patients (69%) received ASCT as first-line therapy and 36 (31%), for recurrent disease. Risk factors affecting ASCT were analyzed with use of the Cox regression method. Metastatic disease at diagnosis, recurrence prior to ASCT and performance score <90 were associated with higher rates of disease recurrence/progression. Five-year probabilities of PFS in patients with localized and metastatic disease at diagnosis who received ASCT as first-line therapy were 49% (95% CI 30-69) and 34% (95% CI 22-47) respectively. The 5-year probability of PFS in patients with localized disease at diagnosis, and received ASCT after recurrence was 14% (95% CI 3-30). PFS rates after ASCT are comparable to published rates in patients with similar disease characteristics treated with conventional chemotherapy, surgery and irradiation suggesting a limited role for ASCT in these patients. Therefore, ASCT if considered should be for high-risk patients in the setting of carefully controlled clinical trials.

Alternative donor bone marrow transplant for children with Philadelphia chromosome ALL.

Children with Philadelphia chromosome positive (Ph+) acute lymphocytic leukemia (ALL) have only a 20% event-free survival when treated with chemotherapy alone. Bone marrow transplant (BMT) for patients with matched siblings has been associated with significantly better long-term survival. We asked whether children who lack a matched sibling donor would do as well if an alternative donor was utilized. Between 1987 and 2002, we transplanted 29 children and adolescents using either an unrelated donor (23) or a mismatched family member (six). The conditioning regimen included cytosine-arabinoside, cyclophosphamide and total body irradiation. Graft-versus-host disease (GVHD) prophylaxis consisted of T-cell depletion (antibody T10B9 or OKT3 and complement) with post transplant cyclosporine (CSA). All patients engrafted. Four developed grades III-IV acute GVHD. Three of 24 evaluable patients developed extensive chronic GVHD. Two patients died of relapse (7%). Two long-term survivors (>6 years) died of malignant glioblastoma multiforme. Event-free survival at 3, 5, and 10 years is 56, 51, and 46%, respectively. Five of six patients in >CR2 or relapse at the time of transplant died. Our data should encourage the use of alternative donor transplants early in the course of disease for children with Ph+ ALL.

Bone marrow transplants from mismatched related and unrelated donors for severe aplastic anemia.

For patients with acquired severe aplastic anemia without a matched sibling donor and not responding to immunosuppressive treatment, bone marrow transplantation from a suitable alternative donor is often attempted. We examined risks of graft failure, graft-versus-host disease and overall survival after 318 alternative donor transplants between 1988 and 1998. Sixty-six patients received allografts from 1-antigen and 20 from >1-antigen mismatched related donors; 181 from matched and 51 from mismatched unrelated donors. Most patients were young, had had multiple red blood cell transfusions and poor performance score at transplantation. We did not observe differences in risks of graft failure and overall mortality by donor type. The probabilities of graft failure at 100 days after 1-antigen mismatched related donor, >1-antigen mismatched related donor, matched unrelated donor and mismatched unrelated donor transplants were 21, 25, 15 and 18%, respectively. Corresponding probabilities of overall survival at 5 years were 49, 30, 39 and 36%, respectively. Although alternative donor transplantation results in long-term survival, mortality rates are high. Poor performance score and older age adversely affect outcomes after transplantation. Therefore, early referral for transplantation should be encouraged for patients who fail immunosuppressive therapy and have a suitable alternative donor.

High concordance from independent studies by the Children's Cancer Group (CCG) and Pediatric Oncology Group (POG) associating favorable prognosis with combined trisomies 4, 10, and 17 in children with NCI Standard-Risk B-precursor Acute Lymphoblastic Leukemia: a Children's Oncology Group (COG) initiative.

Chromosome aberrations have a major role in pediatric acute lymphoblastic leukemia (ALL) risk assignment. The Children's Cancer Group (CCG) and the Pediatric Oncology Group (POG) independently assessed the significance of trisomy for chromosomes 4, 10, and 17 in National Cancer Institute (NCI) Standard- and High-Risk ALL. Data from 1582 (CCG) and 3902 (POG) patients were analyzed. Eight-year event-free survivals (EFS) of 91% (CCG) and 89% (POG) (P < 0.001) were achieved in patients assigned to NCI Standard Risk whose leukemic cells had simultaneous trisomies 4, 10, and 17. Both groups showed the degree of favorable prognostic importance increased with the actual number of favorable trisomies. POG analyses also demonstrated hyperdiploidy (> or =53 chromosomes) was less of an independently significant prognostic factor in the absence of these key trisomies. This finding supported conclusions from previous CCG and POG studies that specific trisomies are more important than chromosome number in predicting outcome in pediatric B-precursor ALL. In NCI Higher Risk patients, the number of favorable trisomies was not prognostically significant, but showed the same trend. Moreover, specific trisomies 4, 10, and 17 remain associated with favorable prognosis in Standard-Risk B-precursor ALL, even in the context of very different treatment approaches between the groups.

Increased whole-body protein turnover in sick children with newly diagnosed leukemia or lymphoma.

Using a single dose, [15N]glycine turnover technique, whole body rates of proteins synthesis and breakdown were assessed in six healthy children and in eight children with newly diagnosed leukemia (DeWys, W. D. Cancer Res., 42: 721s-726s, 1982) or lymphoma (Baracos, V., Rodemann, H. P., Dinarello, C. A., and Goldberg, A. L. N. Engl. J. Med., 308: 553-558, 1983). Based on excretion of 15N as urinary ammonia, synthesis (g protein per kg body weight per day) was significantly (p less than 0.025) higher in the cancer patients [5.4 +/- 1.5 (S.D.)] compared to the controls (3.6 +/- 0.9); breakdown was also higher (p less than 0.02) in the patients (5.5 +/- 1.8) compared to the controls (3.1 +/- 1.1). When only the seven patients with leukemia were considered, there also were significant increases in synthesis (5.4 +/- 1.6, p less than 0.05) and breakdown (5.4 +/- 1.9, p less than 0.025) compared to controls. Increases in both synthesis and breakdown were also observed in the patients when the protein turnover data were expressed as a function of the rate of creatinine excretion or the calculated lean body mass. We conclude that whole body protein turnover is increased in sick children at the time of diagnosis with some forms of newly diagnosed cancer.

Thioredoxin expression in primary T-cell acute lymphoblastic leukemia and its therapeutic implication.

Increased expression of intracellular thioredoxin has been implicated in the inhibition of apoptosis and in a decrease in the sensitivity of the malignancies to drug-induced apoptosis. In the present studies, we analyzed expression of thioredoxin in samples from 28 children with T-cell acute lymphoblastic leukemia and analyzed their sensitivity toward inhibition of thioredoxin expression. Thioredoxin was expressed in variable amounts. Higher expression was associated with higher WBC counts. Exogenously added thioredoxin stimulated proliferation of clonogenic cells among the T-cell acute lymphoblastic leukemia samples expressing relatively lower levels of intracellular thioredoxin, whereas there was no effect on the clonogenic cells expressing high levels of thioredoxin. In addition, there was differential sensitivity of the leukemia clonogenic cells toward 1-methylpropyl 2-imidazolyl disulfide, an inhibitor of thioredoxin expression, as compared with normal hematopoietic progenitors. This suggests the possibility of using this approach for treatment. Because overexpression of thioredoxin is associated with resistance to many anticancer drugs, the inhibition of thioredoxin expression may overcome this drug resistance and probably sensitize leukemia cells to other chemotherapeutic agents.

Partially matched bone marrow transplantation in patients with myelodysplastic syndromes.

Six patients with a myelodysplastic syndrome (MDS) were treated with bone marrow transplantation (BMT) using partially-matched related (3) or unrelated (3) donors. Patients' ages ranged from 7 to 31 years (median, 10 years). Bone marrow karyotype abnormalities were present in five patients included four with monosomy 7 and one with trisomy 8. One patient was in complete remission before transplant; the remaining five had excess of blasts or were undergoing leukemic transformation. Donor, and recipient were mismatched at the DR locus (2), A locus (2), B locus (1), or A and B loci (1). Conditioning included busulfan, cytarabine, cyclophosphamide, methylprednisolone, and total body irradiation. Cyclosporine was started on day -1. Marrows were T-cell depleted using a monoclonal antibody (MoAb) (CD3) and normal rabbit serum. Four patients engrafted routinely. One patient died of aspergillosis before engraftment (day 12) and one patient failed to engraft on first attempt, but engrafted following additional preparation. Median time to neutrophils greater than 500/microL and platelets greater than 25,000/microL were 16 and 19 days, respectively. Acute graft-v-host disease (GVHD) was less than or equal to grade II in all patients. One patient died with recurrent disease (day 257). One patient died at day 515 of pancreatitis and respiratory failure. Three patients are alive and disease-free at 240, 395, and 560 days post-BMT including two patients with unrelated donors. Partially matched T-depleted bone marrow from related or unrelated donors may be effective, and possibly curative therapy for patients with MDS who lack a histocompatibility locus antigen (HLA)-identical sibling donor.

Prognostic factors in childhood acute myelogenous leukemia.

The prognostic significance of initial clinical and laboratory parameters was evaluated in 125 children with acute myelogenous leukemia (AML) treated on two consecutive protocols (VAPA and 80-035). Both protocols used an anthracycline with cytosine arabinoside (ara-C) for induction therapy followed by 12 to 14 months of intensive sequential postremission chemotherapy. Results are similar for the two treatment regimens. Seventy-two percent of patients achieved a complete remission, with 42% projected 5-year disease-free survival for the complete responders. Monocytic or myelomonocytic leukemic subtype (French-American-British [FAB] types M4 and M5), WBC count less than 100,000/microL, and age less than 2 years at diagnosis all predicted increased risk of relapse and decreased overall survival in univariate analyses. FAB subtype and high white count continued to predict for an increased risk of relapse in multivariate analyses and only M5 leukemic subtype independently predicted for poor survival. Patients with M4 or M5 leukemic subtype had a higher incidence of initial relapses in the CNS. The addition of intrathecal cytosine arabinoside in the second protocol, 80-035, decreased the percentage of patients with initial failure in the CNS, but did not improve overall survival. Improved CNS prophylaxis, better systemic therapy, and/or different treatment strategies are needed to improve therapy in these high-risk patients.

Treatment of meningeal relapse in childhood acute lymphoblastic leukemia. I. Results of craniospinal irradiation.

Fourteen children were treated for isolated meningeal relapse occurring seven to 44 months (median, 14 months) after prophylactic cranial irradiation (2,400 rad/12 fractions) and intrathecal methotrexate (IT MTX, 12 mg/m2 for four doses during cranial irradiation). Eight had "high-risk" acute lymphocytic leukemia with age less than 2 years, white blood cell counts greater than 20,000, or T cell markers. Treatment for central nervous system leukemia included IT MTX (12 mg/m2 twice weekly until clearance of spinal fluid cytology) followed by craniospinal irradiation (CSI, 3,000 rad/20 fractions to the cranium and 1,800 rad/12 fractions to the spine). No maintenance IT MTX was given. Systemic chemotherapy was continued or reinstituted for a minimum of one year after CSI. No instance of second meningeal relapse has occurred. Five patients remain in secondary complete remission 66+, 54+, 36+, 26+, and 24+ months after meningeal relapse. Disease-free survival was limited by marrow relapse in eight patients (2-20 months after CSI) and testicular relapse in one. No acute toxicities were noted with CSI. Myelosuppression occurred in seven patients. Infections within two months of CSI were noted in five. No neurologic sequelae are apparent. Serial neuropsychometric studies in 10 patients revealed a significant decline in mean values on Global IQ scales. Long-term survival with acceptable toxicity is possible following aggressive, prompt treatment of meningeal relapse occurring after prophylactic cranial irradiation. Hematologic relapse remains the major obstacle to long-term disease-free survival.

Racial differences in the survival of childhood B-precursor acute lymphoblastic leukemia: a Pediatric Oncology Group Study.

PURPOSE: We conducted a historic cohort study to test the hypothesis that, after adjustment for biologic factors, African-American (AA) children and Spanish surname (SS) children with newly diagnosed B-precursor acute lymphoblastic leukemia had lower survival than did comparable white children. PATIENTS AND METHODS: From 1981 to 1994, 4,061 white, 518 AA, and 507 SS children aged 1 to 20 years were treated on three successive Pediatric Oncology Group multicenter randomized clinical trials. RESULTS: AA and SS patients were more likely to have adverse prognostic features at diagnosis and lower survival than were white patients. The 5-year cumulative survival rates were (probability +/- SE) 81.9% +/- 0.6%, 68.6% +/- 2.1%, and 74.9% +/- 2.0% for white, AA, and SS children, respectively. Adjusting for age, leukocyte count, sex, era of treatment, and leukemia blast cell ploidy, we found that AA children had a 42% excess mortality rate compared with white children (proportional hazards ratio [PHR] = 1.42; 95% confidence interval [CI], 1.12 to 1. 80), and SS children had a 33% excess mortality rate compared with white children (PHR = 1.33; 95% CI, 1.19 to 1.49). CONCLUSION: Clinical presentation, tumor biology, and deviations from prescribed therapy did not explain the differences in survival and event-free survival that we observed, although differences seem to be diminishing over time with improvements in therapy. The disparity in outcome for AA and SS children is most likely related to variations in chemotherapeutic response to therapy and not to compliance. Further improvements in outcome may require individualized dosing based on specific pharmacogenetic profiles, especially for AA and SS children.

Childhood acute lymphoblastic leukemia with the MLL-ENL fusion and t(11;19)(q23;p13.3) translocation.

PURPOSE: To determine the molecular characteristics, clinical features, and treatment outcomes of children with acute lymphoblastic leukemia (ALL) and the t(11;19)(q23,p13.3) translocation. PATIENTS AND METHODS: A retrospective analysis of leukemic cell karyotypes obtained from patients with new diagnoses of ALL who were treated at St. Jude Children's Research Hospital or by the Pediatric Oncology Group was performed to identify cases with the t(11;19)(q23;p13.3) translocation. Molecular analyses were performed on these cases to determine the status of the MLL gene and the presence of the MLL-ENL fusion transcript. RESULTS: Among 3,578 patients with ALL and successful cytogenetic analysis, we identified 35 patients with the t(11;19)(q23;p13.3) translocation: 13 infants and 11 older children had B-precursor leukemia, whereas 11 patients had a T-cell phenotype. Although all of the cases examined had MLL rearrangements and MLL-ENL fusion transcripts, outcome varied according to age and immunophenotype. Among B-precursor cases, only two of the 13 infants remain in complete remission, compared with six of the 11 older children. Most strikingly, no relapses have occurred among B-precursor patients 1 to 9 years of age or among T-cell patients. CONCLUSION: Although MLL gene rearrangements are generally associated with a dismal outcome in ALL, two distinct subsets with MLL-ENL fusions have an excellent prognosis. Our results suggest that patients with this genetic abnormality who have T-cell ALL or are 1 to 9 years of age should not be considered candidates for hematopoietic stem-cell transplantation during their first remission.

Comparison of preparative regimens in transplants for children with acute lymphoblastic leukemia.

PURPOSE: Preparative regimens involving total-body irradiation (TBI) produce significant late toxicities in some children who receive bone marrow transplants, including impaired growth and intellectual development. Busulfan is often used as an alternative to TBI, but there are few data regarding its relative efficacy. PATIENTS AND METHODS: We compared outcomes of HLA-identical sibling transplants for acute lymphoblastic leukemia (ALL) in children (< 20 years of age) who received cyclophosphamide plus TBI (CY/TBI) (n = 451) versus those who received busulfan plus cyclophosphamide (Bu/CY) (n = 176) for pretransplant conditioning. Patients received transplants between 1988 and 1995 and their results were reported to the International Bone Marrow Transplant Registry by 144 participating institutions. The CY/TBI and Bu/CY groups did not differ in gender, immune phenotype, leukocyte count at the time of diagnosis, chromosome abnormalities, remission status, or length of initial remission. T-cell depletion was used more frequently in the CY/TBI group; the Bu/CY group included a higher proportion of children who were less than 5 years of age. The median follow-up period was 37 months. RESULTS: The 3-year probabilities of survival were 55% (95% confidence interval [CI], 50% to 60%) with TBI/CY and 40% (95% CI, 32% to 48%) with Bu/CY (univariate P =.003). The 3-year probabilities of leukemia-free survival were 50% (95% CI, 45% to 55%) and 35% (95% CI, 28% to 43%), respectively (univariate P =.005). In a multivariate analysis, the risks of relapse were similar in the two groups (relative risk [RR], 1.30 for Bu/CY v CY/TBI; P =.1). Treatment-related mortality was higher in the Bu/CY group (RR, 1.68; P =.012). Death and treatment failure (relapse or death, inverse of leukemia-free survival) were more frequent in the Bu/CY group (RR, 1. 39; P =.017 for death; RR, 1.42; P =.006 for treatment failure). CONCLUSION: These data indicate superior survival with CY/TBI conditioning, compared with Bu/CY conditioning, for HLA-identical sibling bone marrow transplants in children with ALL.

Bone marrow stroma-supported culture of T-lineage acute lymphoblastic leukemic cells predicts treatment outcome in children: a Pediatric Oncology Group study.

Significant predictors of treatment outcome are poorly defined for patients with T-lineage acute lymphoblastic leukemia (T-ALL). A high WBC at diagnosis, which has traditionally been a predictor of poor response in T-ALL, has considerably weakened prognostic significance in the face of modern, more intensive chemotherapy. To test the hypothesis that bone marrow stroma-supported leukemic cell recovery might identify children at high risk for relapse, we measured the ex vivo recovery of T-ALL lymphoblasts from 29 newly diagnosed patients using a stromal cell co-culture assay. In all cases the T-ALL lymphoblasts showed an increase in recovery of T-ALL cells (RTC), ranging from 4 to 343%, in comparison to samples maintained without stroma. Since we were blinded to patient outcome in this case-control study, we then correlated patient outcome with RTC. The RTC for 18 patients in complete continuous remission (CCR) for greater than 4 years was stochastically larger than for the 11 patients who eventually relapsed (P = 0.011, by the two-sided Wilcoxon test). Furthermore, 100% of patients with an RTC of more than 26% had a CCR greater than 4 years while 78% of the patients with an RTC of less than 25% relapsed within 4 years. This is the first report to show that higher lymphoblast recovery may predict a more favorable outcome for children with T-ALL. A prospective study is needed to test whether stroma-supported leukemic cell recovery might serve as a basis for assigning risk-adjusted therapy.

Slow disappearance of peripheral blood blasts is an adverse prognostic factor in childhood T cell acute lymphoblastic leukemia: a Pediatric Oncology Group study.

The rapidity of response to induction therapy is emerging as an important prognostic factor in children and adolescents with acute lymphoblastic leukemia (ALL). We studied the relationship between rapidity of reduction in peripheral blood blast count and treatment outcome in children with T cell ALL (T-ALL). Initial systemic chemotherapy included prednisone, vincristine, doxorubicin and cyclophosphamide. A Cox analysis evaluated the correlation between the length of time that the peripheral blood absolute blast count (ABC) remained above 1000/mm3 following the start of treatment and event-free survival (EFS). Data were available for 281 patients. Patients for whom the ABC remained >1000/mm3 for 3 or more days following administration of intensive therapy had an estimated 5-year EFS of 34.2% (s.e. = 7.2) vs 58.3% (3.5) for those whose ABC was <1000/mm3 within 0-2 days, with a hazard ratio (HR) of failure of 2.03 (95% CI = 1.35-3.06, P < 0.001) for the slower responding patients. Pre-treatment of some type (usually with prednisone) occurred in 128 patients (average duration 1.7 days). When this was accounted for, patients with an ABC >1000/mm3 for 5 or more days following the start of treatment of any kind had a HR for failure of 2.27 (95% CI = 1.38-3.72, P < 0.001) compared to those responding within 0-4 days. Inclusion of other clinical and biological factors in a multivariate analysis did not alter the prognostic importance of slower blast clearance. Pediatric patients with T-ALL who have a circulating blast count >1000/mm3 at diagnosis and a relatively slower response to initial treatment are at increased risk of treatment failure. Rapidity of response may therefore be a clinically useful prognostic factor for patients with T-ALL.

Acute lymphoblastic leukemia with an unusual t(8;14)(q11.2;q32): a Pediatric Oncology Group Study.

We present the clinicopathologic findings and survival data on 10 patients with acute lymphoblastic leukemia (ALL) and a rare t(8;14)(q11.2;q32). There were five male and five female patients, nine Caucasians and one Black, aged 4-17 (median 10.9) years. Three had Down syndrome. Eight (80%) patients had a white blood cell (WBC) count <50 x 109/l at presentation. No patient had central nervous system involvement or a mediastinal mass. Two patients had concurrent splenomegaly and hepatomegaly. Adenopathy was absent in four, minimal in three, moderate in one and prominent in two patients. All eight cases where immunophenotyping was performed by flow cytometry showed a B-precursor phenotype with expression of CD10 (CALLA). Only one case exhibited t(8;14)(q11.2;q32) as the sole karyotypic abnormality. Three patients were classified as standard-risk and seven high-risk by NCI (National Cancer Institute) consensus risk group categories. All patients achieved complete remission and seven patients were in complete continuous remission (CCR) after chemotherapy designed for B-precursor ALL. Three patients relapsed after 23.5, 31.3 and 32.1 months of EFS; the first patient also had t(9;22)(q34;q11), the second had a WBC count of 126 x 109/l at presentation while the third patient had no high risk features except for age 10 years. Thus, from our data, the t(8;14)(q11.2;q32) does not appear to confer an increased risk of relapse. Further observations are needed to confirm this conclusion.

A comparison of early intensive methotrexate/mercaptopurine with early intensive alternating combination chemotherapy for high-risk B-precursor acute lymphoblastic leukemia: a Pediatric Oncology Group phase III randomized trial.

A prospective, randomized multicenter study was performed to evaluate the relative efficacy of two different concepts for early intensive therapy in a randomized trial of children with B-precursor acute lymphoblastic leukemia (ALL) at high risk (HR) for relapse. Four hundred and ninety eligible children with HR-ALL were randomized on the Pediatric Oncology Group (POG) 9006 phase III trial between 7 January 1991 and 12 January 1994. After prednisone (PDN), vincristine (VCR), asparaginase (ASP) and daunorubicin (DNR) induction, 470 patients received either 12 intensive parenteral treatments of intermediate dose (1 g/m2 each) methotrexate (MTX) and mercaptopurine (MP) over 24 weeks (regimen A) or 12 intensive course of alternating myelosuppressive drug combinations given over 30 weeks (regimen B). These drug combinations included MTX/MP, teniposide (VM-26)/cytosine arabinoside (AC) and VCR/PDN/DNR/AC/ASP. Central nervous system (CNS) prophylaxis was age-adjusted triple intrathecal chemotherapy. Patients with CNS disease at diagnosis were treated with craniospinal irradiation after the intensive phase. Continuation was standard doses of MTX and MP for 2 years. This trial was closed early because of an apparent early difference favoring regimen B. Results show that 470 patients achieved remission (97%). Two hundred and thirty two were randomized to regimen A and 238 to regimen B. The estimated 4-year event-free survival (EFS) for patients treated with regimen A is 61.6 % (s.e. = 3.3%) and with regimen B is 69.4% (s.e. = 3.1%), P = 0.091. Toxicities were more frequent on regimen B. In conclusion, for children with B-precursor ALL at high risk to relapse, early intensification with myelosuppressive combination chemotherapy was more toxic but produced no significant difference in EFS when compared to those treated with parenteral methotrexate and mercaptopurine.

Effects of cranial radiation in children with high risk T cell acute lymphoblastic leukemia: a Pediatric Oncology Group report.

Contemporary chemotherapy has significantly improved event-free survival among patients with T cell-lineage acute lymphoblastic leukemia (T-ALL). Unlike B-precursor ALL, most investigators are still using cranial radiation (CRT) and are hesitant to rely solely on intrathecal therapy for T-ALL. In this study we assessed the effects of CRT upon event-free survival and central nervous system (CNS) relapses in a cohort of children with high risk features of T cell leukemia. In a series of six consecutive studies (1987-1995) patients were non-randomly assigned their CNS prophylaxis per individual protocol. These protocols were based on POG 8704 which relied on rotating drug combinations (cytarabine/cyclophosphamide, teniposide/Ara-C, and vincristine/doxorubicin/6-MP/prednisone) postinduction. Modifications such as high-dose cytarabine, intermediate-dose methotrexate, and the addition of G-CSF, were designed to give higher CNS drug levels (decreasing the need for CRT), to eliminate epidophyllotoxin (decreasing the risk of secondary leukemia), and to reduce therapy-related neutropenia (pilot studies POG 9086, 9295, 9296, 9297, 9398). All patients included in this analysis qualified for POG high risk criteria, WBC >50000/mm3 and/or CNS leukemia. Patients without CNS involvement received 16 doses of age-adjusted triple intra-thecal therapy (TIT = hydrocortisone, MTX, and cytarabine) whereas patients with CNS disease received three more doses of TIT during induction and consolidation. Patients who received CRT were treated with 2400 cGy (POG 8704) or 1800 cGy (POG 9086 and 9295). CNS therapy included CRT in 144 patients while the remaining 78 patients received no radiation by original protocol design. There were 155 males and 57 females with a median age of 8.2 years. The median WBC for the CRT+ and CRT- patients were 186000/mm3 and 200000/mm3, respectively. CNS involvement at diagnosis was seen in 16% of the CRT+ and 23% of the CRT- groups. The complete continuous remission rate (CCR) was not significantly different for the irradiated vs. non-irradiated groups (P = 0.46). The 3-year event-free survival was 65% (s.e. 6%) and 63% (s.e. 4%) for the non-irradiated vs. the radiated group. However, the 3-year CNS relapse rate was significantly higher amongst patients who did not receive CRT; 18% (s.e. 5%) vs. 7% (s.e. 3%) in the irradiated group (P = 0.012). Our analysis in a non-randomized setting, suggests that CRT did not significantly correlate with event-free survival but omitting it had an adverse effect on the CNS involvement at the time of relapse.

In vitro drug-resistance profile in infant acute lymphoblastic leukemia in relation to age, MLL rearrangements and immunophenotype.

Acute lymphoblastic leukemia (ALL) in infants under 1 year is strongly associated with translocations involving 11q23 (MLL gene), CD10-negative B-lineage (proB) immunophenotype, and poor outcome. The present study analyses the relationship between age, MLL rearrangements, proB-lineage, and in vitro drug resistance determined using the MTT assay. Compared to 425 children aged over 1 year with common/preB (c/preB) ALL, the 44 infants were highly resistant to steroids (for prednisolone (PRED) more than 580-fold, P=0.001) and L-asparaginase (L-ASP) (12-fold, P=0.001), but more sensitive to cytarabine (AraC) (1.9-fold, P=0.001) and 2-chlorodeoxyadenosine (2-CdA) (1.7-fold, P<0.001). No differences were found for vincristine, anthracyclines, thiopurines, epipodophyllotoxines, or 4-hydroperoxy (HOO)-ifosfamide. ProB ALL of all ages had a profile similar to infant ALL when compared with the group of c/preB ALL: relatively more resistant to L-ASP and PRED (and in addition thiopurines), and more sensitive to AraC and 2-CdA. Age was not related to cellular drug resistance within the proB ALL group (<1 year, n=32, vs >/=1 year, n=19), nor within the MLL-rearranged ALL (<1 year, n=34, vs >/=1 year, n=8). The translocation t(4;11)(q21;q23)-positive ALL cases were more resistant to PRED (>7.4-fold, P=0.033) and 4-HOO-ifosfamide (4.4-fold, P=0.006) than those with other 11q23 abnormalities. The expression of P-glycoprotein, multidrug-resistance protein, and lung-resistance protein (LRP) was not higher in infants compared to older c/preB ALL patients, but LRP was higher in proB ALL and MLL-rearranged ALL of all ages. In conclusion, infants with ALL appear to have a distinct in vitro resistance profile with the proB immunophenotype being of importance. The role of MLL cannot be excluded, with the t(4;11) being of special significance, while age appears to play a smaller role.

Secondary cytogenetic aberrations in childhood Philadelphia chromosome positive acute lymphoblastic leukemia are nonrandom and may be associated with outcome.

Additional chromosomal aberrations occur frequently in Philadelphia chromosome positive (Ph+) acute lymphoblastic leukemia (ALL) of childhood. The treatment outcome of these patients is heterogeneous. This study assessed whether such clinical heterogeneity could be partially explained by the presence and characteristics of additional chromosomal abnormalities. Cytogenetic descriptions were available for 249 of 326 children with Ph+ ALL, diagnosed and treated by 10 different study groups/large single institutions from 1986 to 1996. Secondary aberrations were present in 61% of the cases. Chromosomes 9, 22, 7, 14, and 8 were most frequently abnormal. Most (93%) karyotypes were unbalanced. Three main cytogenetic subgroups were identified: no secondary aberrations, gain of a second Ph and/or >50 chromosomes, or loss of chromosome 7, 7p, and/or 9p, while other secondary aberrations were grouped as combinations of gain and loss or others. Of the three main cytogenetic subgroups, the loss group had the worst event-free survival (P=0.124) and disease-free survival (P=0.013). However, statistical significance was not maintained when adjusted for other prognostic factors and treatment. Karyotypic analysis is valuable in subsets of patients identified by molecular screening, to assess the role of additional chromosomal abnormalities and their correlation with clinical heterogeneity, with possible therapeutic implications.