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At least 325 records · Page 18Linked to original sources

Initial prognostic factors in small-cell lung cancer patients predicting quality of life during chemotherapy. Swiss Group for Clinical Cancer Research (SAKK).

The question of whether initial prognostic factors in small-cell lung cancer patients have a predictive value for patients' quality of life (QL) during chemotherapy is addressed in the context of a randomised clinical trial comparing early and late alternating chemotherapy (SAKK protocol 15/84). The relative impact of initial tumour stage and performance status, previous weight loss, sex and age on patient-rated QL was analysed over six chemotherapy cycles in 124-130 patients (according to available QL data) with more than 400 questionnaires. Fatigue/malaise, personal functioning, emotional and general well-being were prospectively selected as QL indicators. Predefined summary measures (average QL score over chemotherapy cycles, 'minimum', 'maximum' and 'final' improvement) were analysed separately by scale in various patient groups. General linear models adjusted for treatment arm and response were used to confirm the univariate findings. Within the overall sample, the average QL scores over six cycles were predicted by initial prognostic factors. Patients with poor prognostic factors reported worse QL. Within a limited sample (with baseline QL), patients with poor prognostic factors reported worse QL at baseline and greater improvement under treatment. Graphical comparison of QL patterns over cycles showed permanent discrimination by levels of prognostic factors. The impact of initial prognostic factors was consistently confirmed in the three analyses. Levels of performance status and weight loss best discriminated QL. Initial tumour stage, performance status and previous weight loss can predict QL in small-cell lung cancer during chemotherapy, even after controlling for response to treatment. Our results may contribute to clinical decision-making with regard to the intensity of chemotherapy and QL outcome, especially in patients with extensive disease.

Antineoplastic Combined Chemotherapy Protocols↗

Complete remission of metastatic clear cell sarcoma with DAV chemotherapy.

We report the first case of metastatic clear cell sarcoma with dramatic response to DAV treatment (DTIC + ACNU + VCR). Clear cell sarcoma of tendons and aponeuroses, or malignant melanoma of soft parts, is a rare tumour that occurs predominantly in the extremities of young adults. It tends to recur locally or metastasize and the prognosis is poor. Although the importance of surgery has been established, the role of adjuvant chemotherapy has yet to be determined. DAV should be considered as a first-line palliative treatment in disseminated disease as well as adjuvant therapy after surgery of primary clear cell sarcoma.

Antineoplastic Combined Chemotherapy Protocols↗

Pineal malignant rhabdoid tumor with chondroid formation in an adult.

A pineal tumour in a 27-year-old male is presented with the characteristic histological features of a pineal malignant rhabdoid tumor (MRT) with chondroid formation. Occasionally, tumor cells contained a single well-demarcated hyaline globular inclusion within the cytoplasm adjacent to the nucleus. The stroma of these tumors tends to be densely hyalinized and become chondroid. Immunohistochemical staining was positive for vimentin, epithelial membrane antigen, chromogranin A, synaptophysin, neuron-specific enolase, S-100 protein, and muscle actin. Despite surgery and radiochemotherapy, the tumor recurred in the pineal region and metastasized to the lower lobe of right lung. The patient died 2 years after the initial diagnosis. This is the second published case of central nervous system-MRT appearing in an adult. The clinical and pathological features of pineal MRT in this patient are presented.

Adult↗

Modulation of O6-methylguanine-DNA methyltransferase-mediated 1-(4-amino-2-methyl-5-Pyrimidinyl)- methyl-3-(2-Chloroethyl)-3-nitrosourea resistance by antisense RNA.

Mer+ HeLa S3 tumor cells with high levels of O6-methylguanine-DNA methyltransferase (MGMT) gene expression were transduced by retroviral-mediated MGMT antisense RNA. The MGMT mRNA, MGMT protein, and MGMT activity in transduced cells were only 28.7%, 32.7%, and 39. 1% of that in HeLa S3 cells, respectively. The transduced cells showed more sensitive to ACNU than HeLa S3 cells both in cell survival and in nude mice experiments. Pathologic examination confirmed that transduced grafts were killed by ACNU. Our results suggested that MGMT gene expression could be modulated by retroviral-mediated antisense RNA and that Mer+ tumor drug resistance to ACNU could be reversed by modulation of MGMT gene expression.

Animals↗

[Standards and new developments in the chemotherapy of glioblastomas].

For 25 years involved-field radiotherapy has remained the mainstay of postoperative treatment for glioblastoma. In contrast, the role of adjuvant chemotherapy in addition to radiotherapy has remained controversial. A recent randomized multinational phase III trial (EORTC 26 981/22 981/NCIC CE.3) assessing concomitant and adjuvant chemotherapy with the alkylating agent, temozolomide, in addition to radiotherapy in newly diagnosed glioblastoma defines an increase in median survival from 12.1 months with radiotherapy alone to 14.6 months with radiochemotherapy and an increase in the 2-year survival rate from 10 to 26 %. Subgroup analysis revealed that the gain in survival in the experimental arm was largely achieved in patients with glioblastomas which exhibited a methylation of the promoter region of the O (6)-methylguanine DNA methyltransferase (MGMT) gene and thus did not express MGMT. MGMT is a DNA repair enzyme which repairs DNA lesions induced by chemotherapy with alkylating agents. The cellular MGMT stores are consumed during DNA repair, suggesting that temozolomide itself may deplete MGMT and thus overcome its own most important pathway of resistance. EORTC 26 981/22 981/NCIC CE.3 thus defines a milestone in the treatment of glioblastoma and will provide a platform for further efforts at improving the outcome for patients suffering from this still invariably fatal neoplasm.

Antineoplastic Agents, Alkylating↗

[Chemotherapy in malignant gliomas].

Considering the survival time of patients with malignant gliomas indication for chemotherapy in spite of side effects is recommended. One third of them are living 2 years, some even longer. Before starting such a treatment a critical evaluation is mandatory, a prolongation of dying must be avoided. In addition personal human care to the patient and his family has a great importance.

Antineoplastic Agents↗

Interactions of human fibroblast interferon with chemotherapeutic agents and radiation against human gliomas in nude mice.

The growth inhibitory effects of the combination of beta-interferon (beta-IFN) and conventional anticancer drugs such as adriamycin (ADM) and ACNU were evaluated in nude mice receiving subcutaneous transplants of human glioblastoma. Next, the anticancer and radiation sensitizing effects of beta-IFN on human glioblastoma was also evaluated in nude mice model. After three weeks of combined treatment, tumour reduction rates (treated/control values) were evaluated by the Battelle's method. In conclusion, the growth inhibitory effect of IFN was most enhanced when IFN was administered following radiotherapy. Furthermore, the combined effect was enhanced in proportion to the dose of radiation.

Animals↗

Microspectrofluorometric evaluation of single- and double-stranded DNA in short-term cultured human glioma cells.

Seven cerebral gliomas in short-term culture were studied by microspectrofluorometry and acridine orange staining to assess their nuclear content of single- and double-stranded DNA. Benign gliomas showed a diploid DNA pattern, whereas malignant gliomas revealed a higher frequency of DNA aneuploidy and hyperploidy. The content of single-stranded DNA remained relatively low in benign gliomas; however, that in malignant gliomas varied widely. After ACNU treatment, the double-stranded DNA histograms showed S-phase-specific accumulation in all cases but 1 with increasing concentrations of ACNU. The single-stranded DNA content decreased considerably in 2 cases, which responded well to chemotherapy and showed clinical amelioration.

Adult↗

Cross-resistance pattern in brain tumour cells resistant to antitumour chloroethylnitrosoureas.

We tested acquired resistance and cross-resistance of brain tumour cells after repeated treatments of antitumour agents including chloroethylnitrosoureas (CENUs) in clinical use for brain tumour chemotherapy. Within ten repeated 2-day incubation periods with either 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) or methyl-6-[3-(2-chloroethyl)-3-nitrosoureido]-6-deoxy-alpha-D-glucopyr anoside (MCNU), brain tumour cells (9L) developed high degrees of resistance to these drugs, as evidenced by about 3- and 6-fold increases, respectively, at the 10% survival dose (SD10). The resistance has unchanged with time after termination of challenging treatments. Repeated challenges with bleomycin (BLM), cis-diaminedichloroplatinum (II) (CDDP), and methotrexate (MTX) did not develop a significant resistance. ACNU-resistant (9L/ACNU) cells showed complete cross-resistance to MCNU, and MCNU-resistant (9L/MCNU) cells to ACNU. Drug sensitivity to other DNA-damaging agents (BLM, NCS, CDDP, etoposide) than CENUs fluctuated to a lesser extent among 9L parent, 9L/ACNU, and 9L/MCNU cells. These data suggest clinical disadvantage of prolonged adjuvant CENU chemotherapy and advantage of combined CENU chemotherapy with other agents than CENUs in brain tumours.

Animals↗

A single cell gel electrophoresis technique for the detection of DNA damage induced by ACNU, an alkylating agent or irradiation in murine glioma cell lines.

A simple and convenient technique for in situ quantification of DNA damage induced by 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloro-ethyl)-3-nitrosourea hydrochloride (ACNU) an alkylating agent, or irradiation was demonstrated in C6 glioma cells using a single cell gel electrophoresis. Treatment with ACNU or irradiation caused a dose dependent DNA damage which was detected by measuring the length of migration of fragmentary DNA in individual cells. Wild type C6 cells treated with ACNU (0, 10, 30, 60 micrograms ml-1) for one hour showed longer distance of migration of DNA than the ACNU-resistant subtype cells (C6R), indicating that ACNU-sensitive C6 cells were more vulnerable to ACNU than C6R cells. The results of DNA migration in C6 and C6R cells treated with ACNU were consistent with that from MTT assay which had been regarded as a standard method for chemosensitivity test. Furthermore, a time course study for DNA repair activity of C6 and C6R cells was also performed by measuring the length of DNA migration after incubation (0, 15, 30, 60, 120 min) of cells treated with 60 micrograms ml-1 ACNU. C6R cells repaired DNA damage more rapidly than C6 cells. In addition, the technique was also used to measure the DNA damage in C6 cells exposed to 0, 2, 6, 8, 10 Gy of x-ray irradiation, and a dose-dependent DNA migration after radiation injury was observed. This technique appears to be simple and useful for assessing chemosensitivity or radiosensitivity in individual glioma cells.

Alkylating Agents↗

Antitumor effect and peritumoral brain edema formation in relation to MX2, ACNU, and doxorubicin therapy: a comparative analysis using rodent models of gliomas.

The potential antitumor effect of MX2, a new lipophilic morpholino anthracycline, was compared with those of ACNU or doxorubicin (DOX) using two different rodent glioma models. A mouse subcutaneous glioma model (203 glioma) was used to measure the effect of each drug on reducing the glioma size and a rat 9L intracerebral glioma model (9L glioma) was used to assess the antitumor effect on survival rate in a clinically similar fashion. Treatment with ACNU inhibited tumor growth by 94.6% (p < 0.0001) and complete regression of the tumor was observed in 3 of 25 (12.0%) of the ACNU-treated cases. Tumor growth was inhibited by 32.4% with DOX despite a tendency (p < 0.16) and by 59.4% with MX-2 (p < 0.001); neither of these drugs resulted in complete tumor regression. In the intracerebral glioma rats, only ACNU tended to ameliorate survival rate, but there was no statistical significance. These results suggest that ACNU has the most potent effect but MX2 can be an option for chemotherapy of malignant gliomas. Interestingly, all three drugs significantly elevated the brain water content on both the ipsilateral and contralateral sides of the tumor, although they did not induce brain edema in the normal rat brains. Careful management of brain edema might be required regardless of the drug used during chemotherapy to maximize the prognosis of glioma patients.

Animals↗

O6-(fluorobenzyl)guanine and chloroethylnitrosourea in xenografted rat brain tumor in vivo.

O6-methylguanine-DNA methyltransferase (MGMT), one of the DNA repair enzymes, potently repairs DNA damage induced by chloroethylnitrosoureas (CENUs). Depletion of MGMT activity after treatment with MGMT inhibitors increases the sensitivity of tumor cells to CENUs. We tested the effect of O6-(4-, 3- and 2-fluorobenzyl)guanines (4F, 3F and 2F, respectively), three newly synthesized MGMT inhibitors, on 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nit rosoureahydrochloride (ACNU) therapy in C6 tumor xenografts. Treatment with 4F + ACNU and 3F + ACNU significantly decreased tumor volume and extended the delay of growth in comparison to untreated mice (control group, p < 0.05). Both groups showed significantly lower proliferating indices than the control group (p < 0.05) 12 h after treatment. In contrast, 2F did not enhance the ACNU anti-tumor effect. These results indicate that O6-(4- and 3-fluorobenzyl)guanines as well as O6-benzylguanines enhance the effect of ACNU on the growth of C6 tumor xenografts in vivo.

Animals↗

Regression of refractory rhabdomyosarcoma after allogeneic stem-cell transplantation.

A 17-year-old girl developed refractory rhabdomyosarcoma. An allogeneic peripheral-blood stem-cell transplant was performed after a myeloablative regimen. Although rapid disease progression had resolved transiently, after the start of high-dose chemotherapy, re-progression was apparently observed from day 14. However, delayed tumor regression occurred on day 30, shortly after the reduction of immunosuppressants. She achieved a partial remission. The second tumor regression provides suggestive clinical evidence that graft-versus-tumor effect may occur against rhabdomyosarcoma. Although further investigation is required, allogeneic stem-cell transplantation could provide a new therapeutic option for refractory rhabdomyosarcoma.

Adolescent↗

5-Azacytidine-induced recovery of O6-alkylguanine--DNA alkyltransferase activity in mouse Ha821 cells.

Mouse Ha821 cells, Harvey murine sarcoma virus-transformed NIH3T3 cells, have extremely low O6-alkylguanine--DNA alkyltransferase (O6AGTase) activity and are hypersensitive to an anti-tumor chloroethylating agent 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU). The treatment of Ha821 cells with a DNA demethylating agent, 5-azacytidine, resulted in an increase in the frequency of ACNU-resistant cell clones. All randomly isolated ACNU-resistant cell clones were found to have O6AGTase activity comparable to the level of the parental NIH3T3 cells. These results suggest that reversible loss of O6AGTase activity in Ha821 cells is caused at least in part by inactivation of the O6AGTase gene due to methylation of cytosine in the gene.

Animals↗

Predominance of Mex+ cells in newly-established human lymphoblastoid cell lines.

Previous studies have demonstrated that approximately one-third of human lymphoblastoid cell lines (LCLs) are deficient in removing O6-methylguanine residues because of the lack of O6-alkylguanine-DNA alkyltransferase (O6-AGT) activity. Such LCLs have been designated Mex-, while the proficient LCLs are Mex+. Our determinations of O6-AGT activity as a function of cellular protein concentration on 37 previously-established LCLs disclosed that the expression of the enzyme was high in 14 (Mex+) and barely detectable in 16 (Mex-). The other seven LCLs showed intermediate activity of the enzyme. By contrast, all of the 28 LCLs that we newly established contained high enzyme activity, implying that they consisted of mainly Mex+ cells. Since the conventional O6-AGT assay on Mex+ cell populations was not capable of detecting the co-existence of Mex- cells as a minor component, we attempted to determine the proportion of Mex- phenotype in newly-immortalized lymphoblastoid cell clones which had been established directly on semisolid agar. All of the 15 independent clones derived from a single blood sample also showed high O6-AGT activity, rendering it unlikely that Epstein-Barr virus transformation per se was responsible for the generation of Mex- LCLs. These results collectively indicate that Mex+ cells predominate in LCLs shortly after establishment and also suggest that the possible growth advantage for Mex- cells should play an important role in the subsequent development of Mex- LCLs during the long-term culture in vitro.

Cell Line↗

Hypersensitivity of human tumor xenografts lacking O6-alkylguanine-DNA alkyltransferase to the anti-tumor agent 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitros ourea.

Human tumor cell strains having different activities of O6-alkylguanine-DNA alkyltransferase (ATR) were transplanted into nude mice and chemotherapeutic responses of tumor xenografts were compared after intraperitoneal injection of the anti-tumor drug 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea (ACNU). The tumor strains used were four Mer+ strains possessing high ATR activity and three Mer- strains lacking this activity. Included in these Mer+ strains was a clone 5'dD which expresses the Escherichia coli ATR in Mer- HeLa cells and thus shows the Mer+ phenotype. All the Mer- tumor xenografts were much more sensitive than tumors of Mer+ strains, including the clone 5'dD; after the highest ACNU dose (three injections of 50 mg/kg), some Mer- tumors disappeared completely and the growth of other tumors was severely retarded, whereas all Mer+ tumors continued to grow. These results demonstrate that ATR activity in tumor cells is a major determinant of tumor response to ACNU, and further suggest that measurement of ATR activity in biopsy specimens may provide a useful guide to predict the response to chemotherapy.

Animals↗

Evidence for spontaneous conversion of Mex- to Mex+ in human lymphoblastoid cells.

A series of human lymphoblastoid cell lines (LCLs) called Mex- were defined by Sklar and Strauss on the basis of their inability to remove O6-methylguanine from DNA. Instability of Mex- has previously been shown as a population phenotype of LCLs. We examined whether Mex- as a cellular phenotype is spontaneously convertible or not. At the population doubling number (PDN) 23 after recloning, two out of 15 independent subcultures derived from a Mex- LCL, AT1-1, were found to contain a small fraction of Mex+ cells after treatment with 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea (ACNU). Three Mex+ subclones were identified without exposure to ACNU among 486 subclones from replica plating of an expanded Mex- clone (PDN30). The rate of spontaneous conversion was estimated to be in the range of 10(-8)-10(-7) per cell per generation by the fluctuation analyses on two Mex- subclones. These results strongly support the hypothesis that Mex- as a cellular phenotype is spontaneously convertible to Mex+.

Cell Line↗