Deregulation of a homeobox gene, HOX11, by the t(10;14) in T cell leukemia.

Molecular cloning of the t(10;14)(q24;q11) recurrent breakpoint of T cell acute lymphoblastic leukemia has demonstrated a transcript for the candidate gene TCL3. Characterization of this gene from chromosome segment 10q24 revealed it to be a new homeobox, HOX11. The HOX11 homeodomain is most similar to that of the murine gene Hlx and possesses a markedly glycine-rich variable region and an acidic carboxyl terminus. HOX11, while expressed in liver, was not detected in normal thymus or T cells. This lineage-restricted homeobox gene is deregulated upon translocation into the T cell receptor locus where it may act as an oncogene.

Unique forms of the abl tyrosine kinase distinguish Ph1-positive CML from Ph1-positive ALL.

In the Philadelphia chromosome (Ph1) of chronic myelogenous leukemia (CML), the c-abl gene on chromosome 9 is translocated to bcr on chromosome 22. This results in the expression of a chimeric bcr-abl message that encodes the P210bcr-abl tyrosine kinase. The cells of 10% of acute lymphocytic leukemia patients (ALL) carry a cytogenetically similar Ph1 translocation. We report that Ph1-positive ALL cells express unique abl-derived tyrosine kinases of 185 and 180 kilodaltons that are distinct from the bcr-abl-derived P210 protein of CML. The appearance of the 185/180-kilodalton proteins correlates with the expression of a novel 6.5-kilobase messenger RNA. Thus, similar genetic translocations in two different leukemias result in the expression of distinct c-abl-derived products.

Expression of a distinctive BCR-ABL oncogene in Ph1-positive acute lymphocytic leukemia (ALL).

The Philadelphia chromosome (Ph1) is a translocation between chromosomes 9 and 22 that is found in chronic myelogenous leukemia (CML) and a subset of acute lymphocytic leukemia patients (ALL). In CML, this results in the expression of a chimeric 8.5-kilobase BCR-ABL transcript that encodes the P210BCR-ABL tyrosine kinase. The Ph1 chromosome in ALL expresses a distinct ABL-derived 7-kilobase messenger RNA that encodes the P185ALL-ABL protein. Since the expression of different oncogene products may play a role in the distinctive presentation of Ph1-positive ALL versus CML, it is necessary to understand the molecular basis for the expression of P185ALL-ABL. Both P210BCR-ABL and P185ALL-ABL are recognized by an antiserum directed to BCR determinants in the amino-terminal region of both proteins. Antisera to BCR determinants proximal to the BCR-ABL junction in CML immunoprecipitated P210BCR-ABL but not P185ALL-ABL. Nucleotide sequence analysis of complementary DNA clones made from RNA from the Ph1-positive ALL SUP-B15 cell line, and S1 nuclease protection analysis confirmed the presence of BCR-ABL chimeric transcripts in Ph1-positive ALL cells. In Ph1-positive ALL, ABL sequences were joined to BCR sequences approximately 1.5 kilobases 5' of the CML junction. P185ALL-ABL represents the product of a BCR-ABL fusion gene in Ph1-positive ALL that is distinct from the BCR-ABL fusion gene of CML.

Blast cell methotrexate-polyglutamate accumulation in vivo differs by lineage, ploidy, and methotrexate dose in acute lymphoblastic leukemia.

High-dose methotrexate (HDMTX) is a component of most treatment protocols for childhood acute lymphoblastic leukemia (ALL), yet recent studies of receptor-mediated transport and saturable polyglutamylation have questioned its rationale. To investigate this in vivo, methotrexate and its active polyglutamated metabolites (MTX-PG) were measured in bone marrow blasts obtained from 101 children randomized to single-agent therapy with either HDMTX (1 g/m2 per 24 h i.v., n = 47) or low-dose MTX (LDMTX, 30 mg/m2 by mouth every 6 h x 6, n = 54), before remission induction therapy. Blast concentrations of total MTX-PGs (median 460 vs 1380 pmol/10(9) cells) and of long-chain MTX-glu4-6 were both significantly higher after HDMTX (P < 0.001). With either treatment, MTX-PGs were significantly higher in B-lineage blasts than in T-lineage blasts (LDMTX P = 0.001, HDMTX P = 0.03). In a multiple regression analysis of B-lineage ALL, blast MTX-PG was significantly related to MTX dose (or plasma MTX concentration), lymphoblast ploidy (hyperdiploid > nonhyperdiploid), and percentage S-phase. This is the first evidence that HDMTX achieves higher MTX-PG concentrations in ALL blasts in vivo, establishing a rationale for HDMTX in the treatment of childhood ALL, especially T-lineage or nonhyperdiploid B-lineage ALL, disease characteristics associated with a poor prognosis on conventional therapy.

Stroma-supported culture in childhood B-lineage acute lymphoblastic leukemia cells predicts treatment outcome.

We developed a stroma cell culture system that suppresses apoptosis of malignant cells from cases of B-lineage acute lymphoblastic leukemia. By multiparameter flow cytometric measurements of cell recovery after culture on stromal layers, we assessed the growth potential of 70 cases of newly diagnosed B-lineage acute lymphoblastic leukemia and related the findings of treatment outcome in a single program of chemotherapy. The numbers of leukemic cells recovered after 7 d of culture ranged from < 1 to 292% (median, 91%). The basis of poor cell recoveries from stromal layers appeared to be a propensity of the lymphoblasts to undergo apoptosis. The probability of event-free survival at 4 yr of follow-up was 50 +/- 9% (SE) among patients with higher cell recoveries ( > 91%), and 94 +/- 6% among those with reduced cell recoveries (+/- 91%; P = 0.0003). The prognostic value of leukemic cell recovery after culture exceeded estimates for all other recognized high-risk features and remained the most significant after adjustment with all competing covariates. Thus, the survival ability of leukemic cells on bone marrow-derived stromal layers reflects aggressiveness of the disease and is a powerful, independent predictor of treatment outcome in children with B-lineage acute lymphoblastic leukemia.

Clonal analysis of childhood acute lymphoblastic leukemia with "cytogenetically independent" cell populations.

Acute lymphoblastic leukemia (ALL) is generally regarded as a clonal disease in which a single abnormal progenitor cell gives rise to neoplastic progeny. Five of 463 cases of childhood ALL with adequately banded leukemic cells were found to have two cytogenetically independent cell populations. In addition, two of the four cases tested had more than two rearranged immunoglobulin genes and (or) T cell receptor genes. To investigate the clonality of these unusual leukemias, we examined the neoplastic cells for X-linked markers extrinsic to the disease. Leukemic cells from each of the three patients heterozygous for an X-linked, restriction fragment length polymorphism showed a single active parental allele, suggesting that both apparently independent cell populations developed from a common progenitor. These cases provide evidence that leukemogenesis involves a multistep process of mutation and suggest that karyotypic abnormalities may be a late event of malignant transformation.

Distribution fitting and parameterization of individual operator work routine times for small dairy parlors.

A time and motion study was conducted at 13 small dairy farms with average herd sizes less than 100 cows. Parlors were configured with 3 to 6 stalls per side. A data acquisition methodology was developed using a video camera to gather work routine time data in the parlors. A computer-based data logger was used to extract individual event durations during video playback. Each parlor's video record was reviewed in the laboratory so that work routine times across all parlors and operators could be pooled to estimate typical operator performance. There were 34 operator work routine times associated with various procedures in milking parlors that were evaluated in this study. Individual times were compiled for each work routine and a data-fitting program called UNIFIT was used to fit the data to 1 of 4 data models: gamma, lognormal, Weibull, and Pearson #5. Each of 34 work routine variables was fitted, tested, and plotted to determine how well each of those models fit the actual data. Distributions for Pearson #5, lognormal, gamma, and Weibull models were best fitted to 12, 10, 8, and 4 work routine times, respectively. More common tasks such as attaching the milker, grabbing a towel, and drying the udder were more consistently executed and had smaller variances than routines in which the operator would leave the pit to go to the milk room or disassembled the milk collector after milking. One of the better fitting models was the lognormal distribution for the time to "attach milker," which had a low relative discrepancy to the P-P plot (model probability vs. data probability) of 0.019 and a moderate chi(2) test value of 0.358, thus demonstrating a good fit of the model to the data. Simulation tests were compared with observed data to validate models for work routine times and demonstrated that the models accurately predict parlor throughput in small- to medium-sized parlors.

Expression of a multidrug resistance gene in human cancers.

Many cancers have been cured by chemotherapeutic agents. However, other cancers are intrinsically drug resistant, and some acquire resistance following chemotherapy. Cloning of the cDNA for the human MDR1 gene (also known as PGY1), which encodes the multidrug efflux protein P-glycoprotein, has made it possible to measure levels of MDR1 RNA in human cancers. We report the levels of MDR1 RNA in greater than 400 human cancers. MDR1 RNA levels were usually elevated in untreated, intrinsically drug-resistant tumors, including those derived from the colon, kidney, adrenal gland, liver, and pancreas, as well as in carcinoid tumors, chronic myelogenous leukemia in blast crisis, and cell lines of non-small cell carcinoma of the lung (NSCLC) with neuroendocrine properties. MDR1 RNA levels were occasionally elevated in other untreated cancers, including neuroblastoma, acute lymphocytic leukemia (ALL) in adults, acute nonlymphocytic leukemia (ANLL) in adults, and indolent non-Hodgkin's lymphoma. MDR1 RNA levels were also increased in some cancers at relapse after chemotherapy, including ALL, ANLL, breast cancer, neuroblastoma, pheochromocytoma, and nodular, poorly differentiated lymphoma. Many types of drug-sensitive and drug-resistant tumors, including NSCLC and melanoma, contained undetectable or low levels of MDR1 RNA. The consistent association of MDR1 expression with several intrinsically resistant cancers and the increased expression of the MDR1 gene in certain cancers with acquired drug resistance indicate that the MDR1 gene contributes to multidrug resistance in many human cancers. Thus, evaluation of MDR1 gene expression may prove to be a valuable tool in the identification of individuals whose cancers are resistant to specific agents. The information may be useful in designing or altering chemotherapeutic protocols in these patients.

Down-regulated c-myb expression inhibits DNA synthesis of T-leukemia cells in most patients.

We have investigated the functional relevance of c-myb expression for DNA synthesis in patients' T-leukemia cells. [3H]Thymidine incorporation assays of 32 patients' leukemia cells exposed in vitro to c-myb sense or antisense oligodeoxynucleotides served to define two groups of patients: a responder group whose leukemia cells showed 2- to 16-fold lower levels of [3H]thymidine incorporation in c-myb antisense-treated cultures than in c-myb sense-treated cultures (20 patients) and a nonresponder group whose cells showed comparable [3H]thymidine incorporation levels in either c-myb sense- or antisense-treated cultures (12 patients). Down-regulation of c-myb mRNA levels in cells exposed to c-myb antisense oligodeoxynucleotides was comparable in both groups of patients, indicating that differential sensitivity to c-myb antisense oligodeoxynucleotides was not due to differential uptake of these oligodeoxynucleotides. DNA polymerase alpha mRNA levels were down-regulated in cells from the responders but were unaffected in the nonresponder group. These results suggest that c-myb is required for DNA synthesis in cells of many but not all T-leukemia patients and that leukemia cells in which DNA synthesis is not inhibited despite down-regulation of c-myb expression may have undergone some genetic change(s) that obviate(s) the requirement for myb protein.

Cloning of ALL-1, the locus involved in leukemias with the t(4;11)(q21;q23), t(9;11)(p22;q23), and t(11;19)(q23;p13) chromosome translocations.

Chromosomal region 11q23 participates in a number of reciprocal translocations with specific regions of chromosomes 4, 9, 19, and others. These translocations are associated with acute lymphocytic leukemia and acute myelomonocytic, monocytic, and myelogenous leukemia. From a yeast artificial chromosome containing human DNA derived from 11q23 we cloned a DNA fragment which can be used as a probe to detect rearrangements in leukemic cells from the majority of patients with the t(4;11), t(9;11), and t(11;19) translocations. The breakpoints cluster in a small DNA region of less than 5.8 kilobases.

Glucocorticoid receptors in immunological subtypes of childhood acute lymphocytic leukemia cells: a Pediatric Oncology Group Study.

Glucocorticoid receptors were quantitated by a whole cell method in cells from 593 children with acute leukemia at the time of diagnosis. Leukemia cells were also immunologically typed and divided into early pre-B- (not reactive with antibodies to T-lymphocyte antigens, surface immunoglobulin-negative, cytoplasmic immunoglobulin-negative), pre-B- (not reactive with antibodies to T-lymphocyte antigens, surface immunoglobulin-negative, cytoplasmic immunoglobulin-positive), B- (not reactive with antibodies to T-lymphocyte antigens, surface immunoglobulin-positive), and T- (reactive with antibodies to T-lymphocyte antigens) subtypes. There was a median of 9.7 X 10(3) sites per cell in the 359 with early pre-B-acute lymphocytic leukemia, a median of 8.1 X 10(3) sites per cell from 103 patients with pre-B-cell leukemia, and a median of 4.0 X 10(3) sites per cell from 116 patients with T-cell leukemia. The distributions per cell were significantly different among these 3 groups (P less than 0.0001). The 15 patients with B-cell disease had a median of 3.2 X 10(3) sites per cell. At the time of analysis, remission induction data are available for most of these patients. Within the early pre-B- group 291 patients with a median receptor number of 9.9 X 10(3) achieved remission, while 13 with a median receptor number of 4.8 X 10(3) did not. These distributions were significantly different (P = 0.034). Within the pre-B- and T-cell groups the distributions of receptor numbers for responders and non-responders were not significantly different. We conclude that each immunological subtype has characteristic receptor distribution. High receptor number within the null group is associated with the ability of the patient to achieve remission; however, the range of values within each patient group is too broad to use this assay as a predictor of response for any individual patient.

An altered 11-kilobase transcript in leukemic cell lines with the t(4;11)(q21;q23) chromosome translocation.

The 11q23 chromosome band is frequently associated with chromosomal aberrations in human leukemias. We have previously cloned a DNA fragment derived from chromosome 11 which could be used as a probe to detect rearrangements in DNAs from the leukemic cells of patients with the t(4;11), t(9;11), and t(11;19) translocations. In this study we now show that the same probe detects DNA rearrangements in malignant cells from patients with the t(1;11), t(6;11), t(10;11), and del (11q23) chromosomal abnormalities. A second probe obtained from a region located centrometric to the breakpoint cluster detects major and minor transcripts of 12.5 and 11.5 kilobases, respectively, in all cell lines examined. The same probe identifies an altered 11-kilobase RNA in all three independent cell lines with the t(4;11)(q21;q23) chromosome translocation.

Biology and therapy of pediatric rhabdomyosarcoma.

PURPOSE: To review key developments in biology and therapy of rhabdomyosarcoma (RMS) since the early 1970s. PATIENTS AND METHODS: The literature regarding biology, therapy, and late effects of therapy through March 1995 was reviewed. RESULTS: The two major histiotypes, embryonal and alveolar, are characterized by specific genetic abnormalities that provide clues to mechanisms of tumor induction. Alveolar tumors, for example, often possess a chromosomal translocation [t(2;13)(q35;q14)] that fuses the PAX3 gene in band 2q35 with the FKHR gene in band 13q14, creating a novel chimeric protein that could inappropriately activate normal targets of the PAX3 gene product, thereby contributing to tumorigenesis. Recognition of prognostically important patient groups primarily identified by tumor extent, site, and histology, and development of effective risk-based multimodal therapy in randomized trials, have increased long-term survival in RMS from 25% in 1970 to more than 70% in current studies. The most significant recent gain in therapeutic results was realized in patients with gross residual tumor after biopsy. CONCLUSION: Contemporary risk-based therapy cures more than two thirds of children with RMS while minimizing acute and late effects. Increased dose-intensity of known effective agents with hematopoietic growth factor support, new agents, and hyperfractionated irradiation are being evaluated in hopes of further improving therapy. Recent discovery of novel genetic features in this tumor should lead to better methods of diagnosis and risk assessment, and ultimately to identification of molecular targets for specific treatment.

Up-front window trial of topotecan in previously untreated children and adolescents with metastatic rhabdomyosarcoma: an intergroup rhabdomyosarcoma study.

PURPOSE: To investigate the antitumor activity and toxicity of topotecan, used alone and in combination with conventional therapy, in patients with metastatic rhabdomyosarcoma (RMS). PATIENTS AND METHODS: Forty-eight patients younger than 21 years of age with newly diagnosed metastatic RMS received 2.0 to 2.4 mg/m(2) of topotecan intravenously daily for 5 days every 21 days before standard therapy. Two courses were given in the absence of progressive disease or excessive toxicity and response was assessed. Patients with at least a partial response (PR) to topotecan proceeded to therapy with alternating courses of vincristine 1.5 mg/m(2), dactinomycin 1.5 mg/m(2), and cyclophosphamide 2.2 g/m(2) (VAC) and vincristine 1.5 mg/m(2), topotecan 0.75 mg/m(2) daily x 5, and cyclophosphamide 250 mg/m(2) daily x 5. Patients who did not respond to topotecan received continuation therapy with VAC alone. RESULTS: The overall response rate to topotecan was 46% (complete response, 4%; partial response 42%). Unexpectedly, patients with alveolar RMS had a higher rate of response (65%) than those with embryonal RMS (28%; P: = .08). The most common grade 3 or 4 toxicities were neutropenia (67%), anemia (33%), thrombocytopenia (25%), and infection (21%). Two-year failure-free survival and survival estimates were 24% and 46%, respectively. Response to window therapy did not correlate with survival. CONCLUSION: The high response rate and acceptable toxicity profile of topotecan in children with advanced RMS support further evaluation of this agent in phase III trials. The superior responses in alveolar RMS are of interest.

Results of intensive therapy in children with localized alveolar extremity rhabdomyosarcoma: a report from the Intergroup Rhabdomyosarcoma Study.

Preliminary analyses of treatment results and prognostic factors from the first Intergroup Rhabdomyosarcoma Study (IRS I) suggested that alveolar histology and extremity site were among factors associated with an adverse outcome in clinical group I patients whose tumors had been completely resected. A high incidence of alveolar histology among the extremity tumors compounded the problem. These findings prompted an amendment to IRS II shortly after the study opened. Therapy for patients with alveolar extremity tumors in groups I and II was changed to more intensive repetitive pulse vincristine, dactinomycin, and cyclophosphamide (VAC) for 2 years. The outcome of 44 patients who received intensive therapy on IRS II is compared with a control series of 30 patients who were treated on IRS I. The control patients received standard VAC therapy for 2 years or VA for 1 year. Half of group I control patients received local radiotherapy, whereas none was given to group I intensive therapy patients. In both studies group II patients received radiotherapy to the primary tumor site and to identified positive regional lymph nodes. Compared with the control group, patients given more intensive therapy had a longer disease-free survival (DFS) (69% v 43% at 3 years), but this was of marginal significance (P = .06). The overall survival difference (77% v 57% at 3 years) was not significant (P = .23). Despite the limited statistical evidence, there is some indication that intensive therapy improved the prognosis of children with localized alveolar rhabdomyosarcoma (RMS).

Tumor-cell DNA content predicts outcome in children and adolescents with clinical group III embryonal rhabdomyosarcoma. The Intergroup Rhabdomyosarcoma Study Committee of the Children's Cancer Group and the Pediatric Oncology Group.

PURPOSE: The prognostic value of tumor-cell DNA content (ploidy) was evaluated in children with unresectable, nonmetastic rhabdomyosarcoma of embryonal histology. PATIENTS AND METHODS: Flow-cytometric techniques were used to estimate the ploidy of tumor specimens from 34 patients with embryonal rhabdomyosarcoma who were enrolled in the intergroup rhabdomyosarcoma study III (IRS III) from 1985 to 1991. Tumors were classified as diploid or hyperdiploid (DNA content, 1.1 to 1.8 times that of normal diploid cells). The influence of ploidy on clinical outcome was assessed by the Kaplan-Meier technique and Cox regression analysis with stepwise selection. RESULTS: Twelve of the tumor specimens were diploid and 22 were hyperdiploid. The patient groups defined by diploid or hyperdiploid tumors had similar presenting characteristics (eg, age, tumor size, and anatomic site). Significantly more children with hyperdiploid tumors achieved a complete response than did children with diploid tumors (85% v 42%; P = .01). The probability of progression-free survival at 5 years (+/- SE) was 91% +/- 6% for the hyperdiploid group, compared with 17% +/- 11% for the diploid group (P < .001). Hyperdiploidy was also associated with a significantly higher overall survival rate at 5 years: 96% +/- 4% versus 50% +/- 14% (P = .004). Ploidy retained its prognostic significance after adjustment for tumor site in the Cox regression model. CONCLUSION: Tumor-cell ploidy strongly correlates with outcome in children with nonmetastic, unresectable embryonal rhabdomyosarcoma. The two biologically distinct groups identified by this measure would benefit from further refinements in risk-directed therapy.

Clinical features and results of therapy for children with paraspinal soft tissue sarcoma: a report of the Intergroup Rhabdomyosarcoma Study.

Soft tissue sarcomas of the paraspinal region comprised 3.3% (56 of 1,688) of the patients entered and eligible on Intergroup Rhabdomyosarcoma Studies I (IRS-I) and II (IRS-II) (1972 to 1984). These lesions tended to be greater than 5 cm in diameter at diagnosis, invaded the spinal extradural space, and were of the extraosseous Ewing's sarcoma or undifferentiated sarcoma subtype in 55% (30 of 56) of the cases. Patients with tumors in clinical groups II, III, and IV were treated with radiotherapy (XRT) and vincristine-dactinomycin (VA) or VA plus cyclophosphamide (VAC) +/- doxorubicin. Clinical group I patients treated on IRS-II did not receive XRT, while those on IRS-I were randomized to receive VAC +/- XRT. Forty-four of the paraspinal patients (79%) achieved a complete response (CR) compared with 77% (1,260 of 1,632) for patients with disease in other sites. Twenty-seven patients (55%) subsequently relapsed (five local, three regional, four local and distant, and 14 distant). The proportion of patients surviving 5 years by clinical group (stage) from I to IV were 50%, 50%, 62%, and 27%, respectively. Paraspinal patients had somewhat poorer survival than patients with disease in other sites, both in IRS-I and IRS-II; the percentage of paraspinal patients surviving 5 years was 50% and 52% for IRS-I and IRS-II, respectively, whereas these percentages were 55% and 63% for patients with disease in other sites. Histology did not influence the CR rate, but unexpectedly, patients who had embryonal rhabdomyosarcoma (RMS) had the poorest overall survival rate. We concluded that patients with paraspinal lesions may require extended-field radiation therapy to reduce the high local failure rate and more intensive chemotherapy to achieve better local and systemic tumor control.

Benefit of intensified therapy for patients with local or regional embryonal rhabdomyosarcoma: results from the Intergroup Rhabdomyosarcoma Study IV.

PURPOSE: To compare failure-free survival (FFS) and survival for patients with local or regional embryonal rhabdomyosarcoma treated on the Intergroup Rhabdomyosarcoma Study (IRS)-IV with that of comparable patients treated on IRS-III. PATIENTS AND METHODS: Patients were retrospectively classified as low- or intermediate-risk. Low-risk patients were defined as those with primary tumors at favorable sites, completely resected or microscopic residual, or orbit/eyelid primaries with gross residual disease and tumors less than 5 cm at unfavorable sites but completely resected. Intermediate-risk patients were all other patients with local or regional tumors. RESULTS: Three-year FFS improved from 72% on IRS-III to 78% on IRS-IV for patients with intermediate-risk embryonal rhabdomyosarcoma (P =.02). Subset analysis revealed two groups that benefited most from IRS-IV therapy. FFS at 3 years for patients with resectable node-positive or unresectable (group III) embryonal rhabdomyosarcoma arising at certain favorable sites (head and neck [not orbit/eyelid or parameningeal] and genitourinary [not bladder or prostate]) improved from 72% on IRS-III to 92% on IRS-IV (P =.01). Similarly, 3-year FFS for patients with completely resected tumor or with only microscopic disease remaining (group I or II) at unfavorable sites improved from 71% on IRS-III to 86% on IRS-IV (P =.04). Only patients with unresectable embryonal rhabdomyosarcoma (group III) at unfavorable sites had no improvement in outcome on IRS-IV (3-year FFS for IRS-III and IRS-IV, 72% and 75%, respectively; P =.31). CONCLUSION: IRS-IV therapy benefited certain subgroups of patients with intermediate-risk embryonal rhabdomyosarcoma. A doubling of the intensity of cyclophosphamide (or ifosfamide equivalent) dosing per cycle between IRS-III and IRS-IV is thought to be a key contributing factor for this improvement.

The Third Intergroup Rhabdomyosarcoma Study.

PURPOSE: The ultimate goal of the Third Intergroup Rhabdomyosarcoma Study (IRS-III, 1984 to 1991) was to improve treatment outcome in children with rhabdomyosarcoma through clinical trials comparing risk-based protocols of surgery and multiagent chemotherapy, with or without irradiation. PATIENTS AND METHODS: One thousand sixty-two previously untreated, eligible patients who were entered onto the study after surgery were randomized or assigned to treatment by clinical group (I through IV), histology (unfavorable or favorable), and site of the primary tumor. Initial responses, progression-free survival (PFS), and survival (S) were the end points used in comparisons between randomized groups and between patients treated in IRS-III and IRS-II (1978 to 1984). RESULTS: The overall outcome of therapy in IRS-III was significantly better than in IRS-II (5-year PFS, 65% +/- 2% v 55% +/- 2%; P < .001 by stratified testing). Patients with group I favorable-histology tumors fared as well on a 1-year regimen of vincristine and dactinomycin (VA), as did a comparable group treated with VA plus cyclophosphamide (C) (5-year PFS, 83% +/- 3% v 76% +/- 4%; P = .18). Results for patients with group II favorable-histology tumors, excluding orbit, head, and paratesticular sites, were inconclusive regarding the benefit from addition of doxorubicin (ADR) to VA. Patients with group III tumors, excluding those in special pelvic, orbit, and other selected nonparameningeal head sites, fared much better on the more intensive regimens of IRS-III than on pulsed VAC or VAC-VADRC in IRS-II (5-year PFS estimates, 62% +/- 3% v 52% +/- 3%; P < .01); however, there were no significant differences in outcome among the groups treated in IRS-III. Patients with metastatic disease at diagnosis (clinical group IV) did not benefit significantly from the more complex therapies evaluated in IRS-III. CONCLUSION: Intensification of therapy for most patients in IRS-III, using a risk-based study design, significantly improved treatment outcome overall. The largest gain from this strategy was realized in patients with gross residual tumor after biopsy (clinical group III). It was also possible to decrease therapy for selected patient subsets without compromising survival.

Immunologic, cytogenetic, and clinical characterization of childhood acute lymphoblastic leukemia with the t(1;19) (q23; p13) or its derivative.

PURPOSE: To evaluate the immunophenotypes, karyotypes, and clinical features, including treatment responses, of patients with childhood acute lymphoblastic leukemia (ALL) and either a t(1;19)(q23;p13) or a der(19)t(1;19)(q23;p13) translocation. PATIENTS AND METHODS: The lymphoblasts of 45 patients with a balanced translocation, t(1;19) or its derivative form, der(19)t(1;19), were analyzed by cytogenetic and immunologic methods for differences that might suggest distinct subtypes of ALL. This cohort was treated in four consecutive clinical trials with a median overall follow-up duration of 7 years. RESULTS: A pre-B immunophenotype was found in 10 cases with the balanced t(1;19) and 31 with the unbalanced der(19)t(1;19). The four remaining cases, each with a derivative t(1;19), were classified as early pre-B ALL. The characteristic surface antigen profile of the 41 pre-B cases was CD19+/CD10+/CD22+/CD34-/CD20+/-, whether the translocation was balanced or derivative. In contrast to the four early pre-B cases, which had hyperdiploid karyotypes (> 50 chromosomes), the pre-B cases were primarily pseudodiploid. Comparison of presenting clinical and laboratory features, as well as event-free survival, failed to disclose any differences that would warrant separation of pre-B cases with a balanced or derivative translocation. However, neither subgroup responded to therapy as well as patients with early pre-B ALL, each of whom remains in complete remission for > or = 3 years. CONCLUSION: The t(1;19) and the der(19)t(1;19) identify a relatively homogeneous group of patients with pre-B ALL, who can be expected to respond similarly to intensive chemotherapy. The exceptional cases have an early pre-B phenotype with hyperdiploid karyotypes and appear to have favorable prognosis.