Autologous bone marrow transplantation for children with AML in first remission.

In Children's cancer group (CCG) 2891, newly diagnosed patients with AML were randomized between standard and intensive timing induction therapies. Patients in first remission who lacked an HLA matched family donor were randomized between an autologous bone marrow transplantation (ABMT) where marrow was purged with 4 hydroperoxycyclophosphamide and consolidation chemotherapy. One hundred and thirty seven patients received an ABMT. Myeloid and platelet engraftment occurred at a median of 44 and 42 days, respectively. Disease-free survival (DFS), relapse-free survival and overall survival at 8 years post induction were 47% (95% confidence interval (CI): 38-55), 50% (CI: 42-59) and 55% (CI: 46-63), respectively. Multivariate analysis of DFS showed WBC <50 000/microl and having received intensively timed induction therapy were associated with improved DFS. Recipients who received intensive timed induction therapy and whose WBC was less than 50 000/microl had a DFS at 8 years of 62% (CI: 49-73). Conversely, recipients who received intensive timed induction therapy patients whose WBC was > or =50 000/microl had a DFS of 33% (CI: 17-50), P=0.003. The results confirm previous studies that ABMT is effective post remission therapy for pediatric patients with AML in first remission.

Severe Evans's syndrome secondary to interleukin-2 therapy: treatment with chimeric monoclonal anti-CD20 antibody.

Interleukin-2 (IL-2) acts by increasing the efficiency of the immune system to exert a tumoricidal effect. Although it is well known that immune stimulation with IL-2 plays a role in unmasking autoimmune phenomena such as autoimmune thyroiditis, hematological effects such as anemia and thrombocytopenia are more frequently due to toxic non-immune mechanisms. We describe a patient who developed severe Evans's syndrome [autoimmune hemolytic anemia (AHA) and immune thrombocytopenic purpura (ITP)] secondary to IL-2 therapy. ITP was refractory to multiple treatment modalities including steroids and splenectomy. ITP and AHA were initially managed with intravenous gamma globulin therapy and frequent blood transfusions, respectively. Ultimately, immunosuppressive therapy with cyclophosphamide and chimeric monoclonal anti-CD20 antibody (rituximab) were successful in inducing complete remission of Evans's syndrome.

Outcomes of treatment of children and adolescents with recurrent non-Hodgkin's lymphoma and Hodgkin's disease with dexamethasone, etoposide, cisplatin, cytarabine, and l-asparaginase, maintenance chemotherapy, and transplantation: Children's Cancer Group Study CCG-5912.

PURPOSE: To determine the toxicity and response rate in children treated with dexamethasone, etoposide, cisplatin, high-dose cytarabine, and L-asparaginase (DECAL) for recurrent non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD). PATIENTS AND METHODS: Ninety-seven children with recurrent NHL (n = 68) or HD (n = 29) were enrolled. Treatment consisted of two cycles of DECAL, then bone marrow transplantation or up to four cycles of ifosfamide, mesna, and etoposide alternating with DECAL maintenance therapy. RESULTS: After two cycles of DECAL induction therapy, complete response (CR) or partial response (PR) was reported in 19 (65.5%; 10 CRs and nine PRs) of 29 patients with HD and 29 (41.6%; 23 CRs and six PRs) of 68 patients with NHL. When only 24 patients with HD and 58 patients with NHL who were assessable for response were considered, the response rates were 79.2% (19 of 24 patients) and 50.0% (29 of 58 patients), respectively. Five-year event-free survival was 26% +/- 9% and 23% +/- 5% in patients with HD and NHL, respectively. Five-year survival was 31% +/- 14% and 30% +/- 6%, respectively. Although median time to treatment failure was significantly longer in patients with HD (EFS, P =.002; survival, P =.011), this difference did not translate into a higher long-term survival. Grade 3 or 4 toxic effects were observed during induction in 70 (72%) of 97 patients and during maintenance in 45 (70%) of 64 courses of DECAL therapy. Pancytopenia and systemic infections in particular were frequently observed. Other toxic effects were uncommon. Although not a formal part of the therapy or the study design, 42 patients who responded to therapy who underwent bone marrow transplant did not show any benefit from this approach. CONCLUSION: DECAL is an effective and tolerable salvage regimen for treating patients with recurrent NHL and HD.

A comparison of allogeneic bone marrow transplantation, autologous bone marrow transplantation, and aggressive chemotherapy in children with acute myeloid leukemia in remission.

Intensive, myelosuppressive therapy is necessary to maximize outcomes for patients with acute myeloid leukemia (AML). A comparison was made of 3 aggressive postremission approaches for children and adolescents with AML in a randomized trial, CCG-2891. A total of 652 children and adolescents with AML who achieved remission on 2 induction regimens using identical drugs and doses (standard and intensive timing) were eligible for allocation to allogeneic bone marrow transplantation (BMT) based on matched related donor status (n = 181) or randomization to autologous BMT (n = 177) or to aggressive high-dose cytarabine-based chemotherapy (n = 179). Only 115 patients (18%) refused to participate in the postremission phase of this study. Overall compliance with the 3 allocated regimens was 90%. At 8 years actuarial, 54% +/- 4% (95% confidence interval) of all remission patients remain alive. Survival by assigned regimen ("intent to treat") is as follows: allogeneic BMT, 60% +/- 9%; autologous BMT, 48% +/- 8%; and chemotherapy, 53% +/- 8%. Survival in the allogeneic BMT group is significantly superior to autologous BMT (P =.002) and chemotherapy (P =.05); differences between chemotherapy and autologous BMT are not significant (P =.21). No potential confounding factors affected results. Patients receiving intensive-timing induction therapy had superior long-term survival irrespective of postremission regimen received (allogeneic BMT, 70% +/- 9%; autologous BMT, 54% +/- 9%; chemotherapy, 57% +/- 10%). Allogeneic BMT remains the treatment of choice for children and adolescents with AML in remission, when a matched related donor is available. For all others, there is no advantage to autologous BMT; hence, aggressive nonablative chemotherapy should be used.

Granulocyte-macrophage colony-stimulating factor treatment before doxorubicin and cyclophosphamide chemotherapy priming in women with early-stage breast cancer.

PURPOSE: To determine if inhibition of stem-cell activity induced by granulocyte-macrophage colony-stimulating factor ([GM-CSF]; Sargramostim; Immunex Corporation, Seattle, WA) withdrawal or priming protects hematopoietic stem cells from the cytotoxic effects of adjuvant chemotherapy for early-stage breast cancer. PATIENTS AND METHODS: Serial blood counts were performed in 20 women with early-stage breast cancer receiving four courses of cyclophosphamide and doxorubicin chemotherapy. By a double-blind, placebo-controlled, balanced randomization, subjects received GM-CSF priming on days 5 to 1 for courses 1 and 3 or courses 2 and 4. RESULTS: Compared with before priming, after priming the times to neutrophil nadir (12.8 +/- 2.5 days v 14.8 +/- 1.5 days, respectively; P =.0001) and platelet nadir (mean +/- SD, 10.1 +/- 1.9 days v 11.1 +/- 2.2 days, P <.05) were shorter, indicating a shift of cytotoxicity to later progenitors. The neutrophil nadir was similar with and without priming (mean +/- SD, 490 +/- 310/microL v 550 +/- 350/microL, respectively; P =.2); however, on day 16 the mean neutrophil count was higher (mean +/- SD, 1030 +/- 580/microL v 690 +/- 370/microL, P =.004), and the proportion of patients with a neutrophil count less than 500/microL was lower after priming than before (six of 35 or 17. 1% v 12 of 34 or 35.3%, respectively; P =.04). The platelet nadir was higher (mean +/- SD, 166,000 +/- 51,000/microL after priming v 151,000 +/- 45,000/microL before priming, P =.007), and the duration of thrombocytopenia, ie, a platelet count less than 150,000/microL, was shorter (1.5 +/- 2.1 days v 2.8 +/- 2.9 days, P =.0025) after priming. Episodes of fever and neutropenia were not observed. CONCLUSIONS: GM-CSF priming from days 5 to 1 before doxorubicin and cyclophosphamide chemotherapy was associated with an earlier neutrophil and platelet nadir. On day 16, a higher mean neutrophil count and a lower proportion of patients with severe (< 500/microL) neutropenia were observed. Beneficial effects on the severity and duration of thrombocytopenia were also noted. These observations support the hypothesis that GM-CSF priming protects hematopoietic progenitors from the cytotoxic effects of chemotherapy.

Etoposide with or without mannitol for the treatment of recurrent or primarily unresponsive brain tumors: a Children's Cancer Group Study, CCG-9881.

PURPOSE: This study was undertaken to evaluate the response of recurrent brain tumors to intravenous etoposide and to evaluate the efficacy of mannitol in augmenting etoposide's tumoricidal effect. PATIENTS AND METHODS: Ninety-nine children between one and 21 years of age with recurrent brain tumors were randomly assigned to treatment with intravenous etoposide 150 mg/M2, with or without mannitol 15 gm/M2, daily for five days every three weeks for one year or until disease progression or death. Computerized tomographic (CT) or magnetic resonance image (MRI) scans, obtained after three cycles of therapy, were compared with pre-therapy scans. Scans were centrally reviewed. RESULTS: Of 87 evaluable patients, 12 (13.8%) were determined to have had an objective response by the institutional radiologist. On central review, 7/66 (10.6%) responses were documented. Responses in centrally reviewed patients were observed in 2/12 (16.7%) low grade astrocytomas, 4/26 (15.4%) medulloblastoma or primitive neuroectodermal tumors (PNET), 1/13 (7.7%) high grade astrocytomas and 0/15 (0%) brain stem gliomas. Survival at one year was 53% (SE 12%) for low grade astrocytomas, 38% (SE 7%) for medulloblastoma or PNET, 28% (SE 10%) for high grade astrocytomas and 9% (SE 5%) for brain stem gliomas. An effect of mannitol was not observed. CONCLUSION: Intravenous etoposide has a low level of activity in the treatment of recurrent low grade astrocytomas and medulloblastoma or PNET. The efficacy of this agent was not enhanced by the coincident intravenous administration of mannitol.

Distinctive demography, biology, and outcome of acute myeloid leukemia and myelodysplastic syndrome in children with Down syndrome: Children's Cancer Group Studies 2861 and 2891.

In recent pediatric trials of acute myeloid leukemia (AML), children with Down syndrome (DS) have had significantly more megakaryoblastic leukemia and have experienced better outcome than other children. To further characterize AML in DS, Children's Cancer Group Studies 2861 and 2891 prospectively studied demography, biology, and response in AML and myelodysplastic syndrome (MDS) of children with and without DS. These studies evaluated timing of induction therapy and compared postremission chemotherapy with marrow transplantation in 1,206 children. One-hundred eighteen (9.8%) had DS, a fourfold increase in 20 years. DS patients were younger, had lower white blood cell and platelet counts, more antecedent MDS, acute megakaryoblastic leukemia or undifferentiated AML, and an under-representation of chromosomal translocations (P < .001 for each variable). Four-year event-free survival in DS was 69% versus 35% in others (P < .001). Intensively timed induction conferred significantly higher mortality in DS patients; bone marrow transplantation offered no advantage. Conventional induction followed by chemotherapy achieved an 88%, 4-year, disease-free survival in DS patients versus 42% in others (P < .001). Megakaryoblastic leukemia was unfavorable in others but prognostically neutral in DS. AML in DS is demographically and biologically distinct from AML in other children. It is singularly responsive to conventional chemotherapy and may warrant even less therapy. The increasing proportion of DS patients with AML most likely reflects changes in attitudes about entering DS patients on AML trials and possibly increasing ability to distinguish megakaryoblastic leukemia from lymphoid leukemia.

Timed-sequential induction therapy improves postremission outcome in acute myeloid leukemia: a report from the Children's Cancer Group.

Timed sequencing of cycles of induction chemotherapy in acute myeloid leukemia (AML) has been proposed as a way to achieve maximal leukemic cell kill through recruitment and synchronization of residual neoplastic cells. Furthermore, whether intensive induction therapy should be continued in the presence of profound myelosuppression is an important question. The Children's Cancer Group (CCG) conducted a prospective randomized trial in which 589 patients with AML were randomized at diagnosis to one of two induction approaches involving a 4-day cycle of five active chemotherapeutic agents, with the second cycle administered either 10 days after the first cycle, despite low or dropping blood counts (intensive timing), or 14 days or later from the beginning of the first cycle, depending on bone marrow status (standard timing). All patients achieving remission received a total of four cycles of induction therapy. They were then allocated to allogeneic bone marrow transplantation (BMT) if a compatible family donor was present or randomized to aggressive nonmyeloablative therapy or to myeloablative therapy with purged autologous BMT rescue. The three postremission arms remain coded. Induction success and median days to complete induction were similar for the 295 patients randomized to the intensive timing arm (75%, 99 days) compared with the 294 patients randomized to the standard timing arm (70%, 105 days; P = .18 for remission). However, a marked improvement in outcome was demonstrated in patients randomized to the intensive timing arm, with an actuarial event-free survival at 3 years of 42% +/- 7% (95% confidence interval [CI]) versus 27% +/- 6% for patients on the standard timing arm (P = .0005). Disease-free survival results at 3 years from the end of induction were superior for patients receiving intensively timed induction therapy (N = 211), 55% +/- 9% versus 37% +/- 9% for standard timing patients (N = 195, P = .0002), with a median follow-up from achieving remission of 28 months. Superior results were documented for patients receiving intensive timing irrespective of the postremission therapy to which they were allocated. Intensively timed induction therapy for patients with AML markedly improves event-free survival, even for patients undergoing myeloablative therapy with BMT rescue. Without controlling for the type of induction therapy received, results of various BMT studies in AML comparing different preparative regimens will be difficult to interpret.

Morphologic, immunologic, and cytogenetic classification of acute myeloid leukemia and myelodysplastic syndrome in childhood: a report from the Childrens Cancer Group.

The purposes of this report are to reaffirm concordance difficulties with the acute myeloid leukemia (AML) French-American-British (FAB) classification, to present the frequency of previously delineated AML syndromes in pediatric patients and to describe additional characteristic AML profiles utilizing composite morphologic, cytogenetic and immunophenotypic data. Profiles of 124 children with acute myeloid leukemia (AML) and 13 children with myelodysplastic syndrome entered on the Childrens Cancer Group (CCG) pilot study CCG-2861 were examined. Concordance between institutions and reviewers for FAB designation was 65%. Discordance was found principally between M1 and M2, M2 and M4, and M4 and M5. In 49% of marrow specimens, leukemic blasts expressed at least one T lineage-related antigen; 24% expressed the B lineage-related antigen CD19. CDw14 correlated with FAB M4 or M5 morphology and was the only surface antigen associated with a specific FAB subtype. Normal karyotypes were found for 15% of the 75 children with satisfactory karyotype preparations. Recurring aberrations, found in 76% of children, included t(15;17)(q22;q11), t(8;21)(q22;q22), inv(16)(p13q22), rearrangements of band 11q23, t(6;9) (p23;q34), trisomy 8 and monosomy 7. Results from this pilot study and from the current CCG randomized trial correlating morphology, immunophenotyping and cytogenetics, will help to classify AML into unique subgroups with differing clinical consequences or therapy requirements.

Treatment of advanced malignancies with high-dose acetaminophen and N-acetylcysteine rescue.

High-dose acetaminophen (HDAC) produces hepatocellular necrosis and cytotoxic changes in other tissues that express mixed-function-oxidase (MFO) activity. N-acetylcysteine (NAC), administered within 8 hr of HDAC exposure, replenishes reduced glutathione and prevents these effects. Numerous cell culture and animal studies have demonstrated that NAC may differentially protect normal cells compared with malignant cells from the toxic effects of chemotherapeutic agents and radiation. It was therefore proposed that HDAC with NAC rescue may be effective in malignancies that express MFO activity. To test this hypothesis, a phase I trial of HDAC with NAC rescue was conducted on 19 patients with advanced cancer. HDAC was escalated from 6 to 20 g/m2 PO using a standard IV NAC rescue regimen. A total of 78 treatments were administered. Moderate fatigue, anorexia, and weight loss were the main toxicities observed. Transient grade 3 liver toxicity was noted following 1 treatment. Alopecia and renal and hematological toxicities were not observed. Responses after 4 courses administered weekly were as follows: response in at least 1 site-8 (partial 3, improved 3, mixed 2); stable disease-3; progressive disease-3; inevaluable-5. In conclusion, HDAC was tolerated with moderate fatigue, anorexia, and weight loss but few other effects using a standard IV NAC rescue regimen. A maximum tolerated dose was not reached at 20 g/m2. A 3/19 (15.8%) partial response rate was observed.

Does iron deficiency raise the seizure threshold?

To determine the effect of iron status on the seizure threshold, measures of iron sufficiency were prospectively evaluated in 51 children presenting to a pediatric emergency department with a febrile illness with (26) or without (25) an associated febrile seizure. A higher proportion of children from the febrile seizure group had a family history of mental retardation (5/26 versus 0/25, P = .02) or of previous febrile seizures (10/26 versus 2/23, P = .01). The two groups were otherwise comparable for age, sex, race, family history of afebrile seizures, temperature at presentation, white blood cell count, differential, and vitamin and antibiotic use. Patients with febrile seizures were less frequently iron deficient as defined by a free erythrocyte protoporphyrin level above 0.80 ng/L (2/23 versus 10/25, P < .01), hemoglobin concentration less than 110 g/L (1/26 versus 6/25, P < .03), hematocrit less than 0.30 L/L (0/22 versus 4/25, P < .02), mean corpuscular hemoglobin less than 20 pg (0/25 versus 3/24, P < .04), mean corpuscular volume less than 65 fL (0/26 versus 4/24, P < .02), and platelet count higher than 550 x 10(9)/L (0/26 versus 3/25, P < .04). This association was even stronger when adjusted for differences in family history. None of the patients in the febrile seizure group was being treated for iron deficiency at presentation, whereas three of 25 controls used an iron supplement (P < .04). Iron deficiency may protect against the development of febrile seizures.

Prevention of insulin-dependent diabetes mellitus by 2'-deoxycoformycin in the BB Wistar rat.

The effect of the adenosine deaminase (ADA) inhibitor 2'-deoxycoformycin (dCF) on the development of insulin-dependent diabetes mellitus (IDDM) was assessed in the BB Wistar rat. Sixty-one male rats were treated from days 30 to 120 with 0, 0.5, 1.0 or 1.5 mg dCF/kg/week. The incidence of IDDM was 78% in the controls and was significantly (P < 0.01) decreased in rats receiving 1.5 mg dCF/kg/week (32%), but not in rats receiving lower doses of the drug. However, for those rats that became diabetic the mean time to the development of IDDM was unchanged in animals receiving dCF compared with control. dCF treatment did not produce significant weight loss in the animals or gross changes in the thymus, spleen or kidneys. Although the protective effect of dCF against IDDM was likely produced by immunosuppression, the different dCF dosages had similar effects on ADA suppression in spleen or thymus and on dATP accumulation in these organs.

Evaluation of families wherein a single male manifests a phenotype of X-linked lymphoproliferative disease (XLP).

The Epstein-Barr virus (EBV)-induced diseases of males with X-linked lymphoproliferative disease (XLP) include fatal infectious mononucleosis (IM), non-Hodgkin lymphoma (ML), agammaglobulinemia, and aplastic anemia. These phenotypes also occur as sporadic cases in families, and EBV seronegative males in these families must be considered at risk for XLP until they seroconvert normally to EBV. Given that 50% of males inheriting the defective XLP gene die following primary EBV infection, it is vital that they be identified pre-EBV infection. Here we report results using molecular genetic techniques to provide information as to the relative risks of EBV negative males and potential carrier females in ten families wherein a single male had died of IM.

Intensively timed induction therapy followed by autologous or allogeneic bone marrow transplantation for children with acute myeloid leukemia or myelodysplastic syndrome: a Childrens Cancer Group pilot study.

PURPOSE: Childrens Cancer Group (CCG) protocol 2861 was designed to test the feasibility of aggressively timed induction therapy followed by autologous or allogeneic bone marrow transplantation (BMT) as the sole postremission therapy for newly diagnosed children with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). PATIENTS AND METHODS: Between April 1988 and October 1989, 142 patients were eligible for study. All patients entered received a timing-intensive five-drug induction of dexamethasone, cytarabine (Ara-C), thioguanine, etoposide, and daunorubicin (DCTER) over 4 days with a second cycle administered after 6 days of rest, irrespective of hematologic status at that time. Most patients subsequently received a second two-cycle induction course. Those who achieved remission were eligible for bone marrow ablative therapy with busulfan and cyclophosphamide, followed by 4-hydroperoxy-cyclophosphamide (4-HC)-purged autologous or allogeneic BMT rescue. RESULTS: One hundred eight (76%) patients achieved remission: 19 (13%) died of complications of the leukemia and/or chemotherapy, and 15 (11%) failed to achieve remission. Seventy-four patients subsequently underwent BMT with either autologous (n = 58) or allogeneic (n = 16) rescue. For patients who received autologous rescue with 4-HC-purged grafts, the actuarial disease-free survival (DFS) rate at 3 years from the day of transplant is 51%, compared with 55% for patients who received allogeneic grafts (P = .92). At 3 years, the overall actuarial survival rate for all 142 patients entered on this study is 45%, with an event-free survival (EFS) rate of 37%. Adverse prognostic factors for outcome included an elevated WBC count or the presence of CNS leukemia at the time of AML diagnosis. CONCLUSION: Results suggest that aggressively timed induction therapy followed by marrow ablation and BMT rescue with either autologous or allogeneic grafts for children with newly diagnosed AML or MDS is both feasible and effective.

A role for prostacyclin in bruising symptomatology.

The relationship between bleeding and bruising and the production of prostacyclin and thromboxane was assessed in children who were to have a tonsillectomy and/or an adenoidectomy. Eicosanoids in the blood oozing from the bleeding time incision were measured and correlated with the reported frequency of bruising and epistaxis. A striking association (P = .0003) between prostacyclin production and the frequency of bruising was found; children reporting bleeding at least biweekly had the highest prostacyclin synthesis. Successively lower levels of the prostacyclin metabolite, 6-keto-prostaglandin F1 alpha, were found in children reporting less frequent bruising. Prostacyclin production in bleeding time blood was also correlated inversely with systolic blood pressure and hemoglobin level, although neither of these variables could explain the association between prostacyclin production and bruising. There was no correlation between thromboxane formation, systolic blood pressure, hemoglobin level, age, or bleeding time and the frequency of bruising. The ratio of thromboxane B2 to 6-keto-prostaglandin F1 alpha was correlated inversely with the length of the bleeding time (P = .016). It is concluded that vascular prostacyclin production may have a role in bruising symptomatology. It is suggested that prostacyclin formed at the injured vessel surface collects within the first few seconds after injury inside the tissue space at the site of the bruise and, by influencing the formation of the platelet/fibrin plug and/or the leakage of blood from the vessels, plays a significant role in modifying the development of bruising.

Malignant rhabdoid tumor of the central nervous system with subarachnoid dissemination.

A case of primary central nervous system malignant rhabdoid tumor is presented. Clinical, radiological, and histopathological findings are described in detail. Because of a relatively long clinical course after presentation, it was possible to assess the clinical and radiological response to different treatment modalities: surgery, chemotherapy, and radiotherapy. Despite the complete clinical and radiological response that was achieved after subtotal excision, two cycles of chemotherapy, and high-dose radiotherapy, the tumor recurred within 4 months of completion of the treatment, with wide subarachnoid dissemination. Radiotherapy treatment of whole cranial axis is recommended.

The unstable Hb Hammersmith or alpha 2 beta 2(42)(CD1)Phe----Ser observed in an Indian child; identification by HPLC and by sequence analysis of amplified DNA.

We have identified the unstable hemoglobin variant present in a Chipewayan Indian patient with severe hemolytic anemia as Hb Hammersmith or alpha 2 beta 2(42)(CD1)Phe----Ser. Her parents were normal. Identification was greatly facilitated by the use of reversed phase high performance liquid chromatography for the isolation of the beta X chain and its tryptic fragments, and of sequence analysis of amplified DNA which readily identified a TTT(Phe)----TCT(Ser) mutation at codon 42.

Excretion of mutagens following chemotherapy.

The mutagenic activity of urine was evaluated in children receiving single and multiple agent chemotherapy to determine the duration of carcinogenic risk to health care personnel and family contacts. Urine samples from 21 children were evaluated before and daily for 5 days after chemotherapy administration. Mutagenic activity, a sensitive though not specific indicator of carcinogenic risk, was assayed using mutant strains of Salmonella typhimurium (the "Ames test"). Validity of the assay was confirmed by demonstrating mutagenic activity in urine samples from 17 adult cigarette smokers but not from 21 adult nonsmokers (24/24 versus 0/37, p less than 0.001). None of the 21 children tested demonstrated mutagenic activity before chemotherapy administration. Following single agent dactinomycin, cyclophosphamide, daunorubicin, doxorubicin, methotrexate, or vincristine, mutagenic activity was demonstrated for 2 days (5/5 at 1 and 2 days and 0/5 at 3 days). Following multiple agent chemotherapy using two or three of the latter drugs on a single day, mutagenic activity was demonstrated for 4 or 5 days (16/16 at 1, 2, 3, and 4 days, and 4/16 at 5 days). Based on these observations with urine, and presumably other body fluids, precautions are recommended for 2 days following single agent and at least 5 days following multiple agent chemotherapy.