Search PubMed⌕ Search

Biomedical subjects

J Ritter

Publications and source records attributed to J Ritter.

At least 343 records · Page 19Linked to original sources
PubMedDate not supplied

[Acute lymphoblastic leukemia in infancy: results of 5 multicenter ALL-BFM therapy studies 1970-1986].

Acute lymphoblastic leukemia (ALL) of infancy has in contrast to all other age groups a less favorable prognosis. In order to determine the possible causes and biological principles for impaired outcome of infant patients in five consecutive clinical trials ALL-BFM 1970-1986, both clinical characteristics and biological features for one hundred and ninety-six patients aged two years and less have been evaluated retrospectively (forty-two infants under one year of age). The observations illustrate, that less favorable subtypes of childhood ALL are more frequent in these children, preferably in infants aged six months and less, explaining decisively the impaired prognosis. These subtypes are characterized by large tumor burden (p = less than 0.001), initial central nervous system (CNS) involvement (p = less than 0.001), and a high CNS relapse rate (p = 0.03). Phenotypically the undifferentiated leukemic blast cells show negative reactions for cALLa and often for Tdt (0-ALL and AUL; p = less than 0.001). The switch to prognostically more favorable ALL subtypes occurs about the end of the first year of life. Nevertheless, early failures by non-response or late-response seem not to influence the poorer outcome. However, compared to the preceding trials, results of studies ALL-BFM 81 and ALL-BFM 83 were significantly improved in respect to the probability of continuous complete remission for infant patients (pCCR less than 1 y: 0.44 vs. 0.28), confirming that treatment by itself is one of the major prognostic determinants.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

[Therapy realization and complications in the BFM-83 therapy study of acute myelogenous leukemia].

Data on the realization of therapy are available for 159 out of 173 (92%) protocol patients included in the study AML-BFM-83. The induction therapy could be carried out according to protocol in almost 80% of patients, with a dose compliance (= actual dose/prescribed dose) of greater than or equal to 80% for all substances. During the second therapy phase (consolidation) considerable deviations from the recommended therapy occurred in all nonresponders and in 34% of the patients who had achieved remission. The maintenance therapy had to be reduced in one third of the patients, mainly due to thrombopenias. Lethal complications caused by therapy-induced toxicity, occurred in 7 out of 173 cases (4%), and followed severe infections (mycoses), or other complications such as cardiotoxicity. The proportion of severe complications decreased from the induction through the first to the second consolidation phase. They were rare during maintenance therapy, but markedly more frequent in nonresponders and in children with early relapse (within 12 months). In view of the small differences in dose compliance, it is difficult to determine the prognostic significance of the realization to therapy. With the application of the COX regression and special life table analyses the dose compliance decreases in significance after including the known initial prognostic factors.(ABSTRACT TRUNCATED AT 250 WORDS)

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

[The German Society of Pediatric Oncology Cooperative Ewing Sarcoma Studies CESS 81/86: report after 6 1/2 years].

The GPO Cooperative Ewing's Sarcoma Study (CESS 81 with 10 months four-drug combination chemotherapy (vincristine, actinomycin D, cyclophosphamide, and adriamycin = VACA) and local control with surgery and/or radiation, following week 18, resulted in a Kaplan-Meier estimated disease-free survival of 51% after 6 1/2 years (51/93 patients disease-free). Tumor volume and histological response to primary chemotherapy were identified as most significant prognostic factors. As a consequence, the CESS 86 regimen was stratified according to risk of relapse. Standard risk patients (extremity tumors less than 100 ml tumor volume) were continued on VACA chemotherapy. In high risk patients (extremity tumors greater than 100 ml tumor volume, central tumors), cyclophosphamide in conventional dose (1200 mg/m2/course) was replaced by high doses of ifosfamide (6 g/m2/course) with mesna uroprotection (VAIA). Local control was obtained following week 9. Patients with radiation were randomised for conventional fractionation or accelerated split-course hyperfractionation. The study was piloted from February to December 1985: 27/37 patients were disease-free on October 1, 1987. The ongoing trial was started on January 1, 1986. On October 1, 1987. 63/66 patients were disease-free. In patients with large primaries, according to Kaplan-Meier life-table analysis, the disease-free survival was significantly better in patients receiving VAIA chemotherapy, compared to the previous VACA regimen. The toxicity of both combination chemotherapy regimens was comparable.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

[Cooperative osteosarcoma study COSS-77: results after 4 years].

71 patients with resectable osterosarcoma received chemotherapy for one year including high-dose methotrexate (18 x 200 mg/kg), adriamycin (5 x [2 x 45] mg/m2) and cyclophosphamide (6 x 1200 mg/m2). During the initial 15 weeks adriamycin was used preferentially and cytostatic agents were applied in a higher frequency than later on. 41/71 patients are continuously free of disease with a median follow up of 39 (24-54) months. The latest appearance of pulmonary metastases was observed at 28 months so far. 18/27 (67%) patients with extension of tumor lesion beyond 1/3 long bones length by x-ray examination relapsed in contrast to 12/43 (28%) patients with smaller lesions. 1 patient died from adriamycin induced cardiomyopathy. Generally therapy was well tolerated. An average of 70-80% of planned drug dosages could be realized without measurable influence of individual differences on outcome.

Adolescent↗
PubMedDate not supplied

[Adult form of chronic myelogenous leukemia in childhood--a retrospective analysis of 20 patients].

The initial findings and the course of 20 children and adolescents with adult CML from 10 children hospitals were analyzed retrospectively. The Philadelphia chromosome was found in 18 patients. Initial findings, the course and the prognosis were similar to those published from adult patients. 7 of the 11 children who received chemotherapy alone are still alive with a median survival time of 26 months (range: 14 to 68 months). One patient survived the third blast crisis. For 9 children with a bone marrow transplantation during the chronic phase (median time before transplantation 30 months) the follow-up of 7 months is still too short. 4 of these patients died following graft versus host reaction, 5 show no signs of a renewed occurrence of CML so far. Since CML is rare in children, there is little large scale experience. Hence, there is an urgent need for the prospective and cooperative study of these patients.

Adolescent↗
PubMedDate not supplied

[DNA aneuploidy in children with acute leukemia: I. Incidence and clinical significance within the scope of the BFM studies].

Analyses of the cellular DNA content were carried out in 226 patients with acute lymphoblastic leukemia (ALL) and in 61 children with acute myeloid leukemia (AML) to assess the incidence and clinical significance of DNA aneuploidies. All children were treated within the BFM studies ALL 79/81 and 81/83 as well as AML 78 und 83. DNA aneuploidies were identified in ALL in 39,8% and in AML in 36,1% of cases. Within the ALL group a significantly higher rate of aneuploid DNA stemlines was observed for non-T/non-B ALL with 44,1% as compared to T-ALL with 14,3% (p less than 0,01). In AML the morphologic subgroups M 1/2 revealed a lower frequency of 21,7% DNA aneuploidies than M 4/5 leukemias with 44,4%. The rates of complete remissions were not different between patients with and without DNA aneuploidy neither in ALL nor in AML. In the study ALL 79/81, however, a tendency towards longer remissions for patients with DNA aneuploidy was found (p = 0.053) which could not be confirmed at present by the study ALL 81/83. In both ALL trials patients with the lowest pretherapeutic risk-score revealed the highest rate of aneuploid DNA stemlines.

Aneuploidy↗
PubMedDate not supplied

[DNA aneuploidy in children with acute leukemia: II. Correlation with the phenotype of blasts, clinical picture and course of disease].

Analysis of the cellular DNA content was carried out in 162 children with ALL and 34 children with AML admitted to the university children's hospital Münster between 1979 and 1984. DNA aneuploidies were identified at a similar frequency in ALL (40%) and AML (44%). However, the degree of DNA aneuploidies (DNA-index) was significantly lower in aneuploid AML (median 1.09) than in aneuploid ALL (median 1.19). We found a significantly lower incidence of DNA-aneuploidies in T-ALL (3/21; 14%) as compared to non-T/non-B-ALL (60/137; 44%). No differences were found between children with and without DNA aneuploidy in PAS score and TdT activity. In non-T/non-B-ALL DNA aneuploidy is highly correlated with a long pretherapeutic history, with a low WBC and blast count and with a low serum LDH. Under the conditions of the ALL protocols BFM-79/81 and 81/83 no difference in the remission rate was found between the two patient groups. However, more relapses occurred so far within the group of children without DNS aneuploidy.

Acid Phosphatase↗
PubMedDate not supplied

[The Cooperative Ewing Sarcoma Study CESS 81 of the German Pediatric Oncology Society--analysis after 4 years].

In 1981 the cooperative Ewing's sarcoma study CESS 81 was initiated with initial 18-weeks-chemotherapy consisting of vincristine, actinomycin D, cyclophosphamide and adriamycin (VACA) followed by local therapy consisting of either radical surgery with complete resection of the involved bone or incomplete resection followed by radiation with 36 gy or radiotherapy only. Patients with radiation only for local therapy and extremity tumor sites are randomised for 46 gy vs 60 gy tumor dose. Following local therapy chemotherapy is continued for an additional 18 weeks. The actuarial results of 83 consecutive patients entered from 51 participating institutions from January 1, 1981, until November 15, 1984 are presented. 68/83 patients were off therapy and under observation for longer than one year following diagnosis. The longest follow-up was 41 months. On November 15, 1984, 39/68 (57%) patients were disease free. According to the site of the primary tumor patients with distal extremity lesions had a more favourable prognosis as compared to proximal extremity and central lesions. According to local therapy patients with radical surgery had a better prognosis as compared to those with resection followed by radiation and those with radiation only for local control. Analysis according to tumor volume revealed the strong interaction between tumor site, local therapy and tumor volume. According to life-table-analysis the disease free survival for patients with a tumor volume less than 100 ml was 75% after 41 months compared to 10% for patients with a tumor volume greater than or equal to 100 ml. The consequences of this analysis for a stratified treatment regimen for patients with primary Ewing's sarcoma of bone are discussed.

Adolescent↗
PubMedDate not supplied

[Acute myelogenous leukemia in children: results of the cooperative BFM-78 therapy study after 3 3/4 years].

Between December, 1978, and October, 1982, 151 children with acute myelogenous leukemia from 30 pediatric clinics entered the cooperative study. The treatment consisted of a 10-week intensive induction therapy and a subsequent maintenance therapy, which is terminated for children in complete continuous remission after 2 years. The induction treatment during the first 4 weeks consisted of a combination of prednisone, 6-thioguanine (TG), vincristine, adriamycin (ADR) and cytosine-arabinoside (ARA-C). In the following 4 weeks i.v. cyclophosphamide, i.th. methotrexate and prophylactic cranial irradiation were administered in addition to TG, ARA-C and ADR. 119 of the 151 patients (79%) achieved complete remission. 13 children (9%) died of early hemorrhages, 2 of them before onset of therapy. 5 patients died initially of other complications, another 6 after remission has been achieved. 13 children did not respond or responded poorly to the induction therapy. So far, 40 relapses occurred, mainly in the bone marrow. In 6 relapses the central nervous system was involved. The probability for a continuous complete remission for the total group is 0.41 +/- 0.05 (life table analysis) and for the total group 0.56 +/- 0.06 after 45 months. The corresponding probability for survival after 46 months are 0.43 +/- 0.06 for the remission group. The risk for occurrence of early fatal hemorrhages was higher in children with acute monocytic leukemia than in the other morphological subtypes. An initial leukocyte count of more than 100,000/microliters was found significantly more often in patients who did not achieve remission (early deaths and nonresponders) than in children of the remission group. So far, no factors could be identified which influence the risk for relapse. The present results of the study allow the conclusion, that with the applied treatment strategy it is possible to achieve not only in a high portion of children with AML remission but also to improve the chances for long-time remission and perhaps cure.

Adolescent↗
PubMedDate not supplied

[Philadelphia chromosome-positive acute lymphoblastic leukemia in childhood: a special risk group?].

The Philadelphia chromosome is rarely observed in acute myelogenous and acute lymphoblastic leukemias. There are only a few case reports about pediatric patients, the prognosis of whom seems to be extremely poor. Reviewing the case of a girl aged 18 months with Philadelphia chromosome positive acute lymphoblastic leukemia, the differences between this entity and blast crisis of chronic myelogenous leukemia are described. This subgroup of Philadelphia chromosome positive acute lymphoblastic leukemia may represent a new risk group.

Chromosomes, Human, 21-22 and Y↗
PubMedDate not supplied

Cellular drug resistance in acute myeloid leukemia: literature review and preliminary analysis of an ongoing collaborative study.

Cellular drug resistance is one of the main causes of the frequent ultimate failure of chemotherapy in childhood acute myeloid leukemia (AML). We here summarize the results of a literature review on in vitro drug resistance in childhood AML, focusing on studies using so-called cell culture assays. We also briefly describe some results of an ongoing collaborative study between the Research Laboratory of Pediatric Oncology in Amsterdam (University Hospital Vrije Universiteit) and the German BFM-AML Group. In general, the literature and our preliminary data on in vitro cellular drug resistance in AML are promising in terms of clinical relevance. Cell biological features and clinical response to chemotherapy are related to in vitro drug resistance. However, a large study including multivariate analysis is required to more firmly establish the clinical value of cellular drug resistance testing in childhood AML, and the collaborative study will therefore be continued. Possible applications of cell culture assays include risk-group stratification, rational improvements of current treatment protocols for subgroups of patients based on specific drug resistance profiles, individualised tailored therapy, the study of cross-resistance patterns between drugs, the study of possibilities to modulate or circumvent drug resistance, the study of drug interactions, selection of patients for clinical phase II studies and drug screening.

Acute Disease↗
PubMedDate not supplied

[Primary isolated myeolosarcoma in childhood].

Isolated myelosarcomas are rare first manifestations of acute myeloid leukemia (AML), preceding bone marrow involvement by weeks to months. Seventeen of 654 children observed during the studies AML-BFM 87 and 93 were diagnosed as extramedullar myelosarcomas (2.6%). The predominantly myelomonocytic or monoblastic tumor cells (M4 or M5 according to FAB classification) mainly infiltrated skin (n = 8). Additional tumors were located in mucosa (n = 2), central nervous system (n = 2), orbita (n = 2), bone (n = 1), glandulae parotis (n = 1) and lymph nodes. Due to the initial mild and variable symptoms in some children the diagnostic measurements were delayed and treatment was inadequate. This might be responsible for the high rate of relapse (79%) and the poor outcome. Ten of 17 patients died from disease (estimated survival 0.27 +/- 0.13 compared to AML-BFM 87/93 0.51 +/- 0.03). Suspect skin lesions or tumors should be considered as isolated myelosarcoma of a primary manifestation of AML. An intensive AML-specific chemotherapy is recommended.

Child↗
PubMedDate not supplied

[Prognosis, treatment completion, and complications in nonresponders in the study AML-BFM87].

BACKGROUND: Nonresponders (NR) are patients (pts.) with no or insufficient response to initial treatment, which may be caused by either initial risk factors or poor therapy realization. In study AML-BFM 87, 49 NR of 307 patients (16%) did not achieve remission until the end of intensive chemotherapy and were analysed to assess the specific contribution of prognostic factors, therapy realization and complications of therapy. THERAPY AND METHODS: Therapy started with an 8-day induction therapy followed by a 6-week consolidation and two 5-day intensification blocks with high-dose cytosine-arabinoside and VP-16. Maintenance therapy was given for a total duration of 1.5 years. To evaluate the impact of treatment intensity in NR, we compared the dose compliance (DC = dose given/intended dose), the dose intensity (DI = dose per time given), the treatment results, and toxicity of the individual therapy phases in responders (CR) and NR. RESULTS: In 19 of 49 NR therapy was stopped before starting intensification blocks. Twenty-six NR received at least one block of intensification, and seven patients between three and six intensification blocks. Six children entered maintenance therapy. Twelve patients received a bone marrow transplant (9 allogeneic, 3 autologous). Six (5 after bone marrow transplantation) of 49 NR are still alive for 64 to 108 months. In nearly all patients induction therapy could be applied according to protocol (mean DC: 98%, range 85%-100%), whereas therapy realization was more difficult in the 2nd phase of therapy (mean DC: 92%, range 12%-113%). Deviations from the protocol in the treatment blocks (changes of dose and/or schedule) were mainly attributable to persistence of blasts (n = 33) and septic complications (n = 24). The mean relative DI of 1.01 was according to protocol. Bleeding and infectious complications in the individual therapy phases varied from 7% to 61%. NR compared to CR patients suffered significantly more often from bleeding during the first and second part of consolidation and from infections during the second part of consolidation. Withdrawal from protocol in NR was mainly due to persistence of blasts (n = 16), followed by bone marrow transplantation or other therapies (n = 13), and sepsis (n = 11). CONCLUSIONS: It is difficult to discriminate between nonresponse associated with blast persistence followed by complications and subsequent discontinuation of therapy and nonresponse due to insufficient therapy in patients with complications. Our analyses revealed that therapy with 2 intensifications according to protocol was feasible in 13 NR. Patients' condition permitting, therapy should not be stopped prematurely, in order to sustain the option of BMT after blast cell reduction.

Acute Disease↗