Biomedical subjects

V A Levin

Publications and source records attributed to V A Levin.

At least 55 records · Page 3Linked to original sources

PubMed1997

Treatment of pediatric low-grade gliomas with a nitrosourea-based multiagent chemotherapy regimen.

Between March 9, 1984 and January 29, 1992, 42 children with newly diagnosed symptomatic or previously diagnosed progressive low-grade gliomas received outpatient chemotherapy as their primary treatment. This study was a single arm, phase II trial designed to estimate the time to tumor progression and toxicity of this regimen. Procarbazine, 6-thioguanine, and dibromodulcitol were given before lomustine (CCNU) and vincristine was given 1 and 3 weeks after CCNU. Patients were treated for six treatment cycles or until the tumor progressed, whichever came first. Twenty-three patients had juvenile pilocytic astrocytomas, 11 had astrocytomas, one had oligodendroglioma, one had ganglioglioma, and six had radiographically diagnosed low-grade gliomas. The mean age of the patients was 5 years (median, 3 years). The median time to treatment failure was 132 weeks (95% confidence interval: 106, 186 weeks). Only eight patients have died the estimated 5-year survival rate is 78% (95% confidence interval, 60% 87%). There were two episodes of grade 4 neutropenia, and three episodes of grade 4 thrombocytopenia. This regimen was safe, able to be delivered in the outpatient setting, and produced prolonged periods of disease stabilization in children with low-grade gliomas.

Adolescent↗

PubMed1997

The treatment of recurrent cerebral gliomas with all-trans-retinoic acid (tretinoin).

Malignant gliomas continue to be a significant source of mortality in young and middle aged adults. The introduction of new treatment strategies and multidisciplinary approaches has improved the outcome of patients with these tumors only slightly. Because retinoic acid has growth inhibitory activity against glioma and neuroblastoma cells in cultures, we assessed the efficacy of all-trans-retinoic acid in the treatment of recurrent cerebral gliomas. Thirty-six patients with recurrent cerebral gliomas were entered in the study and treated with 120 or 150 mg/ m2/day of all-trans-retinoic acid as a single agent. The drug was given for 3 weeks followed with one week of rest. Two blocks of 4 weeks constituted one course of treatment. One (3%) of 34 evaluable patients had a minor response and 14 (41%) had stable disease. In the rest of the patients (56%), tumors continued to progress despite treatment. The median time to progression of all evaluable patients was 8 weeks, and for the responders was 17 weeks. The higher dose level (150 mg/m2) was associated with high incidence of headache, which responded to dose reduction. The lower dose level was very well tolerated, with mild, mainly dermatological toxicity. All-trans-retinoic acid as a single agent has no significant activity against recurrent cerebral gliomas.

Adolescent↗

PubMed1997

TPDC-FuHu chemotherapy for the treatment of recurrent metastatic brain tumors.

PURPOSE: To evaluate a combination of thioguanine, procarbazine, dibromodulcitol, CCNU (CCNU), fluorouracil, and hydroxyurea (TPDC-FuHu), designed to improve the efficacy of CCNU, in the treatment of recurrent metastatic brain tumors. PATIENTS AND METHODS: One hundred fifteen patients with progressive or recurrent metastatic brain tumors that failed to respond to surgery and/or radiation therapy were enrolled onto a multicenter prospective study between 1989 and 1995. Patients received TPDC-FuHu in a repeated cycle every 6 weeks until recurrence or until they completed six courses. RESULTS: Ninety-seven patients were assessable at the end of the study. Forty-eight had lung cancer (39 non-small-cell [NSCLC] and nine small-cell [SCLC]), 28 had breast cancer, nine had melanoma, and 12 had adenocarcinoma of different origins (three colon, two kidney, one bladder, one stomach, and five of unknown origin). The response and stable disease (SD) rate (overall response rate) was 52%, 66%, 60%, and 22% in patients with NSCLC, SCLC, breast cancer, and melanoma, respectively. Median time to progression (MTP) was 12, 26, 12, and 6 weeks, respectively, for the four groups. Side effects were mild to moderate in the majority of patients. Severe myelosuppression (grade 4) occurred in only 11% of the patients. CONCLUSION: TPDC-FuHu chemotherapy is an active treatment against recurrent brain metastases from breast cancer and SCLC, and to a lesser extent from NSCLC. This regimen is well tolerated and has acceptable toxicity.

Adenocarcinoma↗

PubMed1996

Tight-binding inhibitory sequences against pp60(c-src) identified using a random 15-amino-acid peptide library.

A bacteriophage peptide library containing a random 15-amino-acid insert was screened for identification of peptide sequence(s) that bind pp60(c-src). Sequencing the random insert from more than 100 virions indicated that more than 60% of the phage virions that bound to this enzyme contained a GXXG sequence motif in which X was frequently a hydrophobic residue. The GXXG sequence was often repeated as GXXGXXG. Two nonameric peptides were synthesized to determine whether or not the peptide inhibits pp60(c-src) tyrosine kinase activity and the importance of the glycine residues within this sequence. The peptide containing glycine had a Ki of 24 microM, whereas replacing the glycines with proline increased the Ki value to 3.1 mM.

Amino Acid Sequence↗

PubMed1996

Hypermethylation of the CpG island of p16/CDKN2 correlates with gene inactivation in gliomas.

There is considerable evidence that lack of p16 protein expression is a frequent event in human gliomas. Nevertheless, the molecular mechanisms underlying this absence of p16 protein expression are not completely understood. In some gliomas, homozygous deletions are the main cause of p16/CDKN2 gene inactivation. However, other gliomas lacking p16 expression exhibit intact p16/CDKN2 gene, suggesting that p16/CDKN2 is down-regulated at the transcriptional level. In this study we investigated whether aberrant p16/CDKN2 gene methylation correlated with absence of p16 expression in the latter group of gliomas. In a series of 27 gliomas, 12 malignant tumors exhibited loss of p16/CDKN2 expression but not gene deletion. Methylation analysis of the CpG island in the 5' region of the p16/CDKN2 gene showed that exon 1 was extensively methylated in six and partially methylated in the other six of the 12 malignant gliomas. In contrast, no methylation was observed in four other malignant gliomas and two low-grade gliomas that expressed p16 protein. These results indicate that abnormal hypermethylation of the CpG island encompassing the 5' end of the p16/CDKN2 gene may be a mechanism of transcriptional silencing in gliomas without homozygous deletions.

Brain Neoplasms↗

PubMed1996

Mutagen sensitivity and risk of gliomas: a case-control analysis.

Although the risk factors contributing to the etiology of brain tumors remain largely unknown, this pilot study suggests that genetically determined sensitivity to environmental carcinogens may play a role in the pathogenesis of these tumors. In this study, we examined short-term lymphocyte cultures from 45 adult malignant glioma patients and 117 age-, sex-, and ethnicity-matched healthy controls for mutagen-induced chromatid breaks and evaluated their family history of cancer, smoking, and demographic variables to ascertain the association between mutagen sensitivity and risk of brain tumors. The mutagen selected was gamma-radiation. The mean number of induced breaks/cell was 0.72 (SD=0.45) for the cases and 0.45 (SD = 0.35) for the controls (P < 0.0001). Using the median number of induced breaks/cell in the controls as the breakpoint for defining mutagen sensitivity, we observed an unadjusted odds ratio of 5.36 (95% confidence interval = 2.12-13.69) for mutagen sensitivity and brain tumor risk and an adjusted odds ratio of 5.79 (2.26-14.83), when we controlled for epidemiological risk factors including smoking, race, income, and education. Although a larger study is needed to confirm this intriguing result, these preliminary findings suggest that increased sensitivity to radiation is an independent risk factor for gliomas.

Adult↗

PubMed1996

Adenovirus-mediated transfer of the p53 gene produces rapid and generalized death of human glioma cells via apoptosis.

Wild-type p53 is involved in several aspects of cell cycle control and suppression of transformation, inducing either apoptosis or G1 block in cell cycle progression. Using a recombinant adenovirus containing the wild-type p53 cDNA, the biological effects of the newly expressed wild-type p53 protein were examined in six human glioma cell lines. Three cell lines (U-251 MG, U-373 MG, and A-172) expressed endogenous mutant p53, and the other three (U-87 MG, EFC-2, and D54 MG) expressed wild-type p53. The restoration of normal p53-encoded protein in the mutant cell lines induced apoptosis as assessed by morphological studies using nuclear staining, electron microscopy, and flow cytometric assays. In wild-type p53 cell lines, however, the overexpression of wild-type p53 did not result in apoptosis but inhibited cellular proliferation rather drastically and modified the neoplastic phenotype. Differential effects suggest two pathways for glioma oncogenesis and a possible therapeutic strategy.

Adenoviruses, Human↗

PubMed1996

Adenovirus-mediated p16/CDKN2 gene transfer induces growth arrest and modifies the transformed phenotype of glioma cells.

The p16 (MTS1/CDKN2) gene localized at the 9p21 chromosomal region encodes for a cell cycle inhibitor protein and is altered in many human cancers. The frequency of p16 alterations in gliomas exceeds 50%. To restore the missing wild-type p16 gene efficiently in glioma cells an adenovirus vector carrying the full length coding sequence of the wild-type p16 cDNA, Ad5RSV-p16, was constructed. Three human glioma cell lines, U251 MG, U-87 MG and D54 MG, that did not express endogenous p16/CDKN2 gene and were easily infected with adenovirus vectors were selected for these experiments. Introduction of the Ad5RSV-p16 in these malignant glioma cell lines directed the biosynthesis of functional p16 protein in the majority of the exposed cells, significantly inhibited cell growth, influenced cell morphology and modified the transformed phenotype of cells including the ability to form colonies in soft agar. Flow cytometric studies revealed that the majority of the Ad5RSV-p16 infected glioma cells were arrested in the G0-G1 phases of the cell cycle. These results suggest that p16/CDKN2 inactivation is a significant factor in the genesis and progression of gliomas and that the restoration of the wild-type p16 protein could have clinical and therapeutic utility.

Adenoviridae↗

PubMed1996

Mutations of the p16 gene in gliomas.

In the present study we investigated the frequency of p16 gene exon 2 mutations in 35 malignant gliomas, using either direct sequencing of the PCR products or cloning into the pCRII vector and sequencing of the cloned PCR products. No mutations were detected during direct sequencing of the PCR products. However, after sequencing of individual clones, we found multiple mutations in 5 tumors involving codons 73(GCC to ACC, Ala to Thr), 76 (GCC to GTC, Ala to Val), 85(GCT to ACT, Ala to Thr), 98(CAC to TAC, His to Tyr), 102 (GCG to GTG, Ala to Val), 106 (GTG to ATG, Val to Met), 107 (CGC to TGC, Arg to Cys), 127 (GCA to GTA, Ala to Val), 128 (CGG to TGG, Arg to Trp) and 136 (GGC to GAC, Gly to Asp). Mutations were found only in glioblastomas and were either C to T or G to A transitions. Each mutation was detected in a small percentage of tumor cells (1.3-22%) using individual colony sequencing and southern hybridization with mutant oligonucleotides, consistent with the heterogenous cell population of glioblastomas. The presence of p16 gene mutations only in glioblastomas suggests that they are late events in glioma development.

Adult↗

PubMed1996

Correlation of p53 immunoreactivity and sequencing in patients with glioma.

This study examines the relationship between p53 immunostaining and direct sequencing of polymerase chain reaction (PCR) products in 61 gliomas. Glioma tissues obtained from patients at surgery were analyzed immunohistochemically with the monoclonal antibody PAb1801 to detect p53 protein abnormalities. Amplified p53 cDNA from these samples was analyzed by direct sequencing. Four grades of p53 immunostaining were evaluated: grade 0 = no labeling, grade 1 = less than 5% labeled cells, grade 2 = 5-30% labeled cells, and grade 3 = more than 30% labeled cells. Twenty-six of 36 glioblastomas, 14 of 23 anaplastic gliomas, and none of two low-grade gliomas had positive p53 immunoreactivity. Direct sequencing of PCR-amplified p53 cDNA revealed that 10 glioblastomas, 11 anaplastic gliomas, and no low-grade gliomas had mutations. Comparison of p53 immunostaining and sequencing data revealed that among all the gliomas, mutations were found in three of 21 with p53 grade 0, one of 16 with p53 grade 1, seven of nine with p53 grade 2, and 10 of 15 with p53 grade 3. These results indicate a good correlation between the p53 immunostaining and sequencing data when the percentage of abnormal cells within the tumor was greater than 5% (p53 grades 2 and 3). However, the correlation was poor when the percentage of abnormal cells was less than 5% (p53 grade 1) because of the limited sensitivity of sequencing techniques. Thus, p53 immunostaining may be more accurate in detecting p53 alterations when the percentage of abnormal cells is small; however, in rare cases, p53 immunostaining may fail to detect mutations confirmed by sequencing.

Adult↗

PubMed1996

Cognitive dysfunction following surgery for intracerebral glioma: influence of histopathology, lesion location, and treatment.

This study examined the relationship between cognitive function, tumor malignancy, adjunctive therapy, and lesion lateralization following surgery for intracerebral glioma. Neuropsychological test battery results showed no difference between patients with highly malignant gliomas and those with less malignant gliomas, but differences were found for tumor lateralization and type of therapy. Scores on a test of graphomotor speed were lowest for patients who had received radiation or a combination of radiation and chemotherapy, regardless of lesion location. Other test results did not differ according to type of prior treatment but were related instead to tumor lateralization. Left hemisphere lesions were associated with lower scores on verbal tests, while right hemisphere lesions were related to lower scores on a test of facial recognition. These findings suggest that neuropsychological tests may be useful for distinguishing between the diffuse side effects of brain tumor therapy and the focal effects of tumors and surgery on brain functions. In addition, it appears that any differences in cognitive function due to tumor malignancy are eliminated or reduced following surgical intervention.

Adult↗

PubMed1996

Controversies in the treatment of low-grade astrocytomas and oligodendrogliomas.

Patients with low-grade infiltrative astrocytomas and oligodendrogliomas are young, with a relatively long expected survival because their tumors grow slowly. Unfortunately, because radiation therapy, a potential mainstay of the various treatment options, can cause significant damage to the brain, much controversy revolves around the appropriate management of patients diagnosed with these tumors. In this editorial review, I try to cover reasons for this controversy and conclusions that can be drawn from published studies.

Adolescent↗

PubMed1996

Combination of 6-thioguanine, procarbazine, lomustine, and hydroxyurea for patients with recurrent malignant gliomas.

OBJECTIVE: To determine the efficacy of the combination of 6-thioguanine, procarbazine, lomustine, and hydroxyurea for patients with recurrent malignant gliomas after failure of either previous radiotherapy alone or previous radiotherapy plus nitrosourea-based chemotherapy. METHODS: Seventy-seven patients with recurrent malignant gliomas were studied. 6-Thioguanine was administered for 4 days before lomustine, and procarbazine was administered for 1 day before and 2 days after lomustine to potentiate lomustine's antitumor effect. Hydroxyurea was initiated 1 day before lomustine and continued for a total of 3 days. RESULTS: Thirty patients with glioblastomas and 47 patients with anaplastic gliomas were eligible for evaluation. In the glioblastoma group, 2 of 30 patients had a partial response and 8 of 30 patients had stable disease. This group of patients who responded and had stable disease included 6 of 10 patients who had not undergone previous chemotherapy but only 4 of 20 who had undergone previous chemotherapy. The overall median time to disease progression for the glioblastoma group was 9 weeks. In the anaplastic glioma group, 11 of 47 patients had a partial response and 25 of 47 had stable disease, including 23 of 30 without previous chemotherapy and 13 of 17 who had undergone previous chemotherapy. The median time to disease progression for the whole anaplastic glioma group was 24 weeks; however, the time to disease progression was 50 weeks for responding patients who had not undergone previous chemotherapy and 25 weeks for those who had undergone previous chemotherapy. CONCLUSION: Our results indicate that chemotherapy with a combination of 6-thioguanine, procarbazine, lomustine, and hydroxyurea is active for patients with recurrent anaplastic gliomas and glioblastomas not previously treated with nitrosourea-based chemotherapy but is inactive for patients with glioblastomas previously treated with chemotherapy.

Adolescent↗

PubMed1996

Treatment of high-risk medulloblastoma and other primitive neuroectodermal tumors with reduced dose craniospinal radiation therapy and multi-agent nitrosourea-based chemotherapy.

PURPOSE: To investigate toxicity, and progression-free survival (PFS) of children and adults with newly diagnosed medulloblastoma, pineoblastoma, and other primitive neuroectodermal tumors (PNET) with a combined modality regimen of radiation therapy and adjuvant nitrosourea-based chemotherapy. PATIENTS AND METHODS: Between 1984 and 1992, 34 evaluable patients with newly diagnosed tumors were treated with chemotherapy and radiotherapy according to a single-arm phase II study. One cycle of chemotherapy was given prior to and for 6 cycles following craniospinal radiotherapy (CSA). Procarbazine, 6-thioguanine, and dibromodulcitol were given before lomustine (CCNU) to enhance CCNU-induced tumor cell kill and to reduce alkyltransferase repair of ethylated DNA. Vincristine was given 1 and 3 weeks after CCNU to kill cells that began to cycle after the challenge of the first four drugs. Chemotherapy was given in the outpatient setting. CSA radiation was planned to deliver a dose of 54 Gy to the primary tumor site and 24 Gy to the rest of the neuroaxis. Additional radiation was given to bulky disease outside the primary site if present. Hydroxyurea was used during radiotherapy as a radiosensitizer. RESULTS: Patients treated included 27 with medulloblastoma, 5 with pineoblastoma, and 2 with supratentorial PNET. All but 3 medulloblastoma cases were considered high risk either because of bulky residual disease remaining after surgery and/or metastatic disease detected during staging. For the 34 patients, 24 have progressed, 20 have died. Overall estimated PFS was 55% at 3 years and 35% at 5 years. The 5-year survival estimate is 56%. One patient had inadequate staging to determine M stage. Of the remaining 33 patients, there were 19 patients who had metastatic disease at diagnosis (M1 or higher stage) who had a 3- and 5-year PFS of 42 and 21% respectively and 5-year survival of 42%. There were 14 patients who had negative staging (M0 stage) who had a 3- and 5-year PFS of 69 and 52% respectively and 5-year survival of 71%. Of the 27 patients with medulloblastoma, 15 had M1 or higher stage. These 15 patients had a 5-year PFS and overall survival of only 20 and 40% respectively. Medulloblastoma patients with M0 staging had a 5-year PFS and overall survival of 52 and 73% respectively. Overall toxicity was primarily due to mild hematological toxicity and related to the use of the chemotherapy. CONCLUSIONS: The results using this therapy in high-risk groups of patients does not offer any improvement over results reported in other recent studies. The reason for these results may be due to the lowered craniospinal radiation dose.

Adolescent↗

PubMed1996

Treatment of recurrent malignant gliomas with high-dose 13-cis-retinoic acid.

Malignant gliomas account for more than 60% of all primary brain tumors in adults. Adjuvant chemotherapy in addition to radical surgery and radiation therapy has provided only a modest increase in survival. Retinoic acid has been shown to have growth-inhibitory activity against glioma cells in culture. This provides the rationale for a Phase II study using 13-cis-retinoic acid (CRA) in patients with recurrent malignant brain tumors. The objective of this study was to determine the clinical activity of CRA in patients with a histologically proven diagnosis of malignant brain tumor and documented progressive or recurrent disease after radiation and chemotherapy. Fifty patients with documented recurrent disease were treated with CRA as a single agent p.o. at a dose of 60-100 mg/m2 per day. Three weeks of treatment were followed by 1 week of rest. Of the 43 patients who received more than 4 weeks of therapy, 3 (7%) achieved partial response, 7 (16%) achieved minor response, 13 (30%) remained stable, and 20 (47%) had disease progression. The median time from onset of treatment to disease progression for the whole group of 43 patients was 16 weeks (19 weeks for glioblastomas and 11 weeks for anaplastic glioma), whereas that for the 23 patients with partial response and minor response and who remained stable was 66 weeks, and that for the 20 patients with progressive disease was only 8 weeks. The median survival time for glioblastoma was 58 weeks, and 34 weeks for anaplastic astrocytoma. Toxicity was mainly dermatological, with dry skin and cheilitis. These preliminary results suggest that 13-cis-retinoic acid is active against malignant gliomas and is very well tolerated.

Adolescent↗

PubMed1995

Increased levels of p21WAF1/Cip1 in human brain tumors.

The cdk inhibitor p21WAF1/Cip1 (p21), which can be transcriptionally activated by p53, functions to block cell cycle progression. In this study, we analysed the expression of p21 in normal and reactive brain and in gliomas of various malignancy grades. Southern blotting showed no p21 gene deletion. Western blotting and immunohistochemical assay showed that the levels of p21 protein in normal and reactive brain tissue were very low; however, p21 was elevated in a majority of gliomas tested, regardless of their malignancy grades. In glioblastoma multiforme, marked elevation of p21 was observed in samples harboring either wild-type or mutant p53. But, in anaplastic astrocytomas, the level of p21 was not elevated in samples harboring mutant-type p53. Immunohistochemical staining of paraffin-embedded astrocytomas and glioblastomas showed that tumor cells and not contaminating normal cells were positive for p21. Therefore, overexpression of p21 appears to be an early event in the development of glial neoplasms and p53-dependent p21 expression appears to be tumor grade specific.

Biomarkers, Tumor↗

PubMed1995

Phase II study of accelerated fractionation radiation therapy with carboplatin followed by vincristine chemotherapy for the treatment of glioblastoma multiforme.

PURPOSE: To conduct a Phase II one-arm study to evaluate the long-term efficacy and safety of accelerated fractionated radiotherapy combined with intravenous carboplatin for patients with previously untreated glioblastoma multiforme tumors. METHODS AND MATERIALS: Between 1988 and 1992, 83 patients received 1.9-2.0 Gy radiation three times a day with 2-h infusions of 33 mg/m2 carboplatin for two 5-day cycles separated by 2 weeks; following radiotherapy, patients received procarbazine, lomustine (CCNU), and vincristine (PCV) for 1 year or until tumor progressed. RESULTS: Eighty-three patients were evaluable for analysis. Seventy-four of the 83 patients (89%) received one or more courses of PCV; their median survival was 55 weeks. Total resection was performed in 20% (15 of 74), subtotal resection in 69% (51 of 74), and biopsy in 11% (8 of 74); reoperation (total or subtotal resection) was performed in 28 patients (37%). Survival was worst for those > or = 61 year old (median 35 weeks). Fits of the Cox proportional hazards regression model showed covariates individually predictive of improved survival were younger age (p < 0.01), smaller log of radiation volume (p = 0.008), total or subtotal resection vs. biopsy (p = 0.056), and higher Karnofsky performance status (p = 0.055). A multivariate analysis showed that age (p = 0.013) and extent of initial surgery (p = 0.003) together were predictive of a better survival with no other variables providing additional significance. Only 8.4% (7 of 83) of patients had clinically documented therapy-associated neurotoxicity ("radiation necrosis"). CONCLUSION: When comparable selection criteria were applied, the survival in this study is similar to the results currently attainable with other chemoradiation approaches. The relative safety of accelerated fractionated radiotherapy, as used in this study with carboplatin, enables concomitant full-dose administration of chemotherapy or radiosensitizing agents in glioblastoma multiforme patients.

Adult↗

PubMed1995

Radiation therapy and bromodeoxyuridine chemotherapy followed by procarbazine, lomustine, and vincristine for the treatment of anaplastic gliomas.

PURPOSE: To conduct a Phase II study to evaluate the long-term efficacy and safety of radiotherapy combined with intravenous bromodeoxyuridine for patients with anaplastic glioma tumors. METHODS AND MATERIALS: Between 1983 and 1987, study patients received 1.7-1.8 Gy radiation once a day, Monday through Friday, to a total dose of 60 Gy. On the Thursday prior to beginning radiotherapy and for the next 5 weeks (6 weeks total), patients received a continuous 96 h intravenous infusion of bromodeoxyuridine at 0.8 g/m2/24 h; following radiotherapy, patients received procarbazine, lomustine (CCNU), and vincristine (PCV) for 1 year or until tumor progressed. RESULTS: One-hundred thirty eight patients (median age, 43 years) were evaluable for analysis. Estimated 4-year survival for the anaplastic astrocytoma (AA) stratum (n = 116) is 46%. For the astrocytoma (ASTRO) stratum (n = 22), the 6-year survival is estimated at 79%. Estimated 4-year progression-free survival for AAs is 42%, and for ASTROs, 68%. Whole brain irradiation was used in 23% and limited-field irradiation in 77%; patients receiving limited-field irradiation had a better survival rate (p = 0.07). Total tumor resection was performed in 15%, partial resection in 53%, and biopsy only in 32%. For the 81 patients with tumor recurrence, 34 (42%) are known to have received additional treatment(s). For AA, fits of the Cox proportional hazards regression model showed that covariates individually predictive of survival were younger age (p < 0.001), Karnofsky performance score (p = 0.10). Major toxicities were rash during Weeks 1 through 6 requiring dose modification in 14%, Grade > or = III leukopenia in 18%, and Grade > or = III thrombocytopeni in 9%. CONCLUSION: The study suggests that the bromodeoxyuridine-radiotherapy-PCV, compared with other published therapies, can improve progression-free survival, and aggressive treatment of ASTRO patients can lead to substantial increases in survival compared to published survival data.

Adolescent↗