thioguanine-anhydrous and Lymphoma--T-Cell

In study NHL-BFM 90 we investigated the efficacy of an ALL-type treatment without local radiotherapy for childhood T-cell lymphoblastic lymphoma (T-LBL). In particular, the prognostic impact of the speed of tumor regression was evaluated. From April 1990 to March 1995, 105 evaluable patients, 1.1-16.4 years of age, with T-LBL were enrolled into study NHL-BFM 90. Patients with stage I and II received an 8-drug induction followed by a consolidation including high-dose-methotrexate (MTX) and maintenance therapy up to a total therapy duration of 24 months. Patients with stage III and IV received an additional reinduction and cranial radiotherapy (CRT) (12 Gy for prophylaxis) between consolidation and maintenance. Residual tumor after completion of induction had to be resected. No local RT was applied. Patients received intensified chemotherapy if tumor regression on day 33 of induction was <70% or when vital residual tumor was present after the induction phase. With a median follow-up of 6.41 years, pEFS at 5 years is 91.4% (SE+/-2.7%). 101 patients were evaluable for the speed of tumor response. Two patients received intensified therapy due to <70% tumor regression on day 33. Of 19 patients with tumor residues after induction, 2 relapsed as compared to 4 of 80 patients with complete tumor regression. Our data demonstrate that, with intensive ALL-type chemotherapy but no local radiotherapy, an event-free survival rate of 90% can be achieved in childhood T-LBL. Providing tumor regression within 5 weeks is sufficient, tumor remnants after induction have weak prognostic impact.

Topics: Adolescent; Antineoplastic Combined Chemotherapy Protocols; Asparaginase; Austria; Child; Child, Preschool; Combined Modality Therapy; Cranial Irradiation; Cyclophosphamide; Cytarabine; Daunorubicin; Dexamethasone; Disease-Free Survival; Doxorubicin; Drug Administration Schedule; Female; Germany; Humans; Immunophenotyping; Infant; Life Tables; Lymphoma, T-Cell; Male; Mercaptopurine; Methotrexate; Neoplasm Staging; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Prednisone; Radiotherapy, Adjuvant; Remission Induction; Thioguanine; Treatment Outcome; Vincristine

The majority of peripheral T-cell lymphomas were found to lack methylthioadenosine phosphorylase, an enzyme that is essential for the salvage of adenine from methylthioadenosine, a product of polyamine synthesis. Importantly, tumors that lack this enzyme have been shown to be more sensitive to inhibitors of de novo purine synthesis (6-thioguanine, methotrexate).. T-cell lymphomas, in particular peripheral T-cell lymphoma (PTCL), angioimmunoblastic T-cell lymphoma (AITL), and anaplastic large cell lymphoma (ALCL), have only limited and noncurative treatment options.. We report here that a high percentage of PTCL, AITL, and ALCL lack the enzyme methylthioadenosine phosphorylase (MTAP), as do T-cell leukemia and T-cell lymphoblastic leukemia. MTAP-deficient cells cannot cleave endogenous methylthioadenosine to adenine and 5-methylthioribose-1-phosphate, a precursor of methionine, and as a result have enhanced sensitivity to inhibitors of de novo purine biosynthesis. A recently introduced antifolate, pralatrexate, which has been shown to inhibit de novo purine biosynthesis, has been approved for treatment of PTCL and may have an increasing role in therapy. An alternative strategy involving coadministration of methylthioadenosine and high-dose 6-thioguanine has been proposed and may prove to be selectively toxic to MTAP-deficient uncommon lymphomas.. Thus the consequences of MTAP deficiency suggest that new therapeutic interventions for T-cell lymphoma may be feasible.

Topics: Adenine; Aminopterin; Folic Acid Antagonists; Humans; Lymphoma, T-Cell; Purine-Nucleoside Phosphorylase; Purines; Thioguanine; Tissue Array Analysis

A rare case of primary intestinal T-cell lymphoma (ITL) of an 8-year-old boy is reported. Medium- to large-sized tumor cells were betaF1+, CD3+, CD8+. TIA-1+, but CD4-, CD5-, CD30-, CD56-, CD20-, CD79a-, TdT-, consistent with an intraepithelial lymphocyte (IEL) origin. They showed monoclonal rearrangement of the T-cell receptor gamma-chain and no evidence of EBV infection. No clinical, histologic, laboratory, or genetic evidence of celiac disease was detected. In adults, ITL is often associated with enteropathy and has a very poor outcome. Our patient remains in first remission 30 months after finishing the acute lymphoblastic leukemia protocol COALL-07-03 high risk standard.

Topics: Antineoplastic Combined Chemotherapy Protocols; Child; Cyclophosphamide; Cytarabine; Daunorubicin; Dexamethasone; Doxorubicin; Etoposide; Humans; Intestinal Neoplasms; Lymphoma, T-Cell; Male; Mercaptopurine; Methotrexate; Methylprednisolone; Neoplasm Staging; Receptors, Antigen, T-Cell, gamma-delta; Remission Induction; Thioguanine; Vincristine

Non-Hodgkin lymphomas (NHL) in children are the second most common malignant tumors in Kuwait. Until 1995 the patients (pts) received institutional protocols. From October 1995 to September 2000 21 children with NHL were treated. Five children were treated by NHL BFM 90 protocol, 7 pts received NHL BFM 95 scheme, and 9 children underwent therapy abroad or according to different types of protocols. The results of a retrospective analysis of NHL BFM 95 protocol in Kuwait are reported. Seven patients diagnosed with NHL--group B: 3 children with Burkitt lymphoma (B-cell NHL) and group A: 4 children with lymphoblastic lymphoma (T-cell NHL)--were treated from October 1995 to September 2000 in the Kuwait Cancer Control Centre according to NHL BFM 95 protocol. Group B consisted of 2 girls and 1 boy; median age at diagnosis was 4 years 8 months, 2 pts classified as stage II and 1 pt as stage III. All patients were assigned to risk group R2. Median follow-up is 2 years 8 months. Group A included 1 girl and 3 boys; median age at diagnosis was 5 years 8 months, 1 pt classified as stage III and 3 pts as stage IV. All patients were assigned to IR group. Median follow-up is 3 years 6 months. In group B all 3 pts are in 1st CR; in group A 3 pts are in 1st CR and 1 pt having Li-Fraumani syndrome died after the 3rd relapse of disease during therapy. In both groups there was no toxic death, myelotoxicity WHO grade III-IV, hepatotoxicity WHO grade II-III. Treatment results of NHL BFM 95 study in our small group of patients are very optimistic. Six patients are in 1st CR and one died due to progression of disease. Despite the small group of patients, the results suggest that NHL BFM 95 protocol is highly effective and safe with regular supportive care.

Topics: Antineoplastic Combined Chemotherapy Protocols; Asparaginase; Burkitt Lymphoma; Child; Child, Preschool; Combined Modality Therapy; Cyclophosphamide; Cytarabine; Daunorubicin; Dexamethasone; Doxorubicin; Drug Administration Schedule; Etoposide; Female; Follow-Up Studies; Humans; Ifosfamide; Infant; Kuwait; Leucovorin; Lymphoma, B-Cell; Lymphoma, Non-Hodgkin; Lymphoma, T-Cell; Male; Mercaptopurine; Mesna; Methotrexate; Neoplasm Staging; Prednisolone; Prednisone; Survival Rate; Thioguanine; Treatment Outcome; Vincristine

A study of the effect of combined antineoplastic drugs in vitro was carried out by microcalorimetric monitoring of the metabolic activity of treated cells. Power-time curves of growing T-lymphoma cell suspensions, treated with single or combined drugs, were recorded. The extent of the effect was evaluated by changes in the slopes of the microcalorimetric curves and the kinetics of the drug action were interpreted from the time at which these changes reached their maximum value. The method was validated using two well-established drug combinations, the potentiatory effect of dipyridamole on methotrexate cytotoxicity, and the synergism between methotrexate and 6-thioguanine. In the first case, where one drug is not toxic, the modulation may be evaluated by comparing the inhibition produced by the toxic drug alone and in combination with its modulator. Otherwise, when both drugs are toxic, the combined effect must be evaluated by means of their combination index. The measurement procedure is simple, the electric signal is well suited to automation of data acquisition and the response may be evaluated within 5 to 6 h of drug administration. Moreover, we demonstrate that microcalorimetry is a reliable method for the detection of modulatory effects in combination chemotherapy.

Topics: Antineoplastic Agents; Calorimetry; Cell Death; Dipyridamole; Drug Synergism; Humans; Kinetics; Lymphoma, T-Cell; Mercaptopurine; Methotrexate; Thioguanine; Tumor Cells, Cultured