Splicing regulator SLU7 preserves survival of hepatocellular carcinoma cells and other solid tumors via oncogenic miR-17-92 cluster expression.

Resisting death is a central hallmark of cancer cells. Tumors rely on a number of genetic mechanisms to avoid apoptosis, and alterations in mRNA alternative splicing are increasingly recognized to have a role in tumorigenesis. In this study, we identify the splicing regulator SLU7 as an essential factor for the preservation of hepatocellular carcinoma (HCC) cells viability. Compared with hepatocytes, SLU7 expression is reduced in HCC cells; however, further SLU7 depletion triggered autophagy-related cellular apoptosis in association with the overproduction of reactive oxygen species. Remarkably, these responses were not observed in primary human hepatocytes or in the well-differentiated HepaRG cell line. Mechanistically, we demonstrate that SLU7 binds the C13orf25 primary transcript in which the polycistronic oncomir miR-17-92 cluster is encompassed, and is necessary for its processing and expression. SLU7 knockdown altered the splicing of the C13orf25 primary transcript, and markedly reduced the expression of its miR-17, miR-20 and miR-92a constituents. This led to the upregulation of CDKN1A (P21) and BCL2L11 (BIM) expression, two bona fide targets of the miR-17-92 cluster and recognized mediators of its pro-survival and tumorigenic activity. Interestingly, altered splicing of miR-17-92 and downregulation of miR-17 and miR-20 were not observed upon SLU7 knockdown in non-transformed hepatocytes, but was found in other (HeLa, H358) but not in all (Caco2) non-hepatic tumor cells. The functional relevance of miR-17-92 dysregulation upon SLU7 knockdown was established when oxidative stress, autophagy and apoptosis were reversed by co-transfection of HCC cells with a miR-17 mimic. Together, these findings indicate that SLU7 is co-opted by HCC cells and other tumor cell types to maintain survival, and identify this splicing regulator as a new determinant for the expression of the oncogenic miR-17-92 cluster. This novel mechanism may be exploited for the development of antitumoral strategies in cancers displaying such SLU7-miR-17-92 crosstalk.

Oxidative and nitrosative stress and fibrogenic response.

Uncontrolled production of collagen I is the main feature of liver fibrosis. Following a fibrogenic stimulus such as alcohol, hepatic stellate cells (HSC) transform into an activated collagen-producing cell. In alcoholic liver disease, numerous changes in gene expression are associated with HSC activation, including the induction of several intracellular signaling cascades, which help maintain the activated phenotype and control the fibrogenic and proliferative state of the cell. Detailed analyses for understanding the molecular basis of the collagen I gene regulation have revealed a complex process involving reactive oxygen species (ROS) as key mediators. Less is known, however, about the contribution of reactive nitrogen species (RNS). In addition, a series of cytokines, growth factors, and chemokines, which activate extracellular matrix (ECM)-producing cells through paracrine and autocrine loops, contribute to the fibrogenic response.

[Hepatic stellate cells and oxidative stress]. / Células estrelladas hepáticas y estrés oxidativo.

Hepatic fibrosis is a wound-healing response that takes place during chronic liver injury and is characterized by excessive production and deposition of extracellular matrix (ECM) components, mainly collagen type I. Hepatic stellate cells (HSC) are responsible for the excessive production of scar tissue during liver fibrosis. Activation of HSC, the main step in the development of hepatic fibrosis, is mediated by cytokines and reactive oxygen species (ROS) released by damaged hepatocytes and/or activated Kupffer cells and even HSC themselves. While HSC usually remain quiescent, in response to factors promoting liver injury they undergo activation and become highly proliferative and fibrogenic. Indeed a key feature of HSC activation is uncontrolled production of collagen type I. Collagen is a heterotrimeric protein composed of two a1 chains and one a2 chain forming a triple helix structure. Initiation of HSC activation is largely due to paracrine stimulation, whereas the perpetuation of such activated state involves autocrine as well as paracrine loops. This review focuses on the role of oxidant stress on the activation of stellate cells.

Células estrelladas hepáticas y estrés oxidativo / Hepatic stellate cells and oxidative stress

La fibrosis hepática ocurre en la lesión hepática crónica y se caracteriza por la producción excesiva y el depósito de componentes de la matriz extracelular (MEC), fundamentalmente de colágeno de tipo I. Las células estralladas hepáticas (CEH) son las responsables de la producción excesiva de matriz extracelular durante la fibrosis. La activación de las CEH, constituye el paso fundamental del desarrollo de la fibrosis hepática y está mediada por citoquinas específicas y especies reactivas de oxígeno (ERO) que liberan los hepatocitos dañados, las células de Kupffer y las CEH activadas. Aunque las CEH permanecen normalmente en estado quiescente, se activan en respuesta a los factores que promueven la lesión hepática y proliferan y generan matriz. Un rasgo fundamental de la activación de las CEH es la producción incontrolada de colágeno de tipo I con una escasa degradación. El colágeno es una proteína heterotrimérica que se compone de dos cadenas α1 y una cadena α2, formando una triple hélice. El inicio de la activación de las células estrelladas se debe en gran medida a una estimulación paracrina, mientras que la perpetuación de dicho estado activado implica regulación tanto autocrina como paracrina. Esta revisión trata del papel del estrés oxidativo sobre la activación de las CEH

Hepatic fibrosis is a wound-healing response that takes place during chronic liver injury and is characterized by excessive production and deposition of extracellular matrix (ECM) components, mainly collagen type I. Hepatic stellate cells (HSC) are responsible for the excessive production of scar tissue during liver fibrosis. Activation of HSC, the main step in the development of hepatic fibrosis, is mediated by specific cytokines and reactive oxygen species (ROS) released by damaged hepatocytes and/or activated Kupffer cells and HSC. While HSC usually remain quiescent, in response to factors promoting liver injury they undergo activation and become highly proliferative and fibrogenic. Indeed a key feature of HSC activation is uncontrolled production of collagen type I with very little degradation. Collagen is a heterotrimeric protein composed of two α1 chains and one α2 chain forming a triple helix structure. Initiation of stellate cell activation is largely due to paracrine stimulation, whereas the perpetuation of such activated state involves autocrine as well as paracrine loops. This review focuses on the role of oxidant stress on the activation of stellate cells

Abbreviated course of radiation therapy in older patients with glioblastoma multiforme: a prospective randomized clinical trial.

PURPOSE: To prospectively compare standard radiation therapy (RT) with an abbreviated course of RT in older patients with glioblastoma multiforme (GBM). PATIENTS AND METHODS: One hundred patients with GBM, age 60 years or older, were randomly assigned after surgery to receive either standard RT (60 Gy in 30 fractions over 6 weeks) or a shorter course of RT (40 Gy in 15 fractions over 3 weeks). The primary end point was overall survival. The secondary end points were proportionate survival at 6 months, health-related quality of life (HRQoL), and corticosteroid requirement. HRQoL was assessed using the Karnofsky performance status (KPS) and Functional Assessment of Cancer Therapy-Brain (FACT-Br). RESULTS: All patients had died at the time of analysis. Overall survival times measured from randomization were similar at 5.1 months for standard RT versus 5.6 months for the shorter course (log-rank test, P =.57). The survival probabilities at 6 months were also similar at 44.7% for standard RT versus 41.7% for the shorter course (lower-bound 95% CI, -13.7). KPS scores varied markedly but were not significantly different between the two groups (Wilcoxon test, P =.63). Low completion rates of the FACT-Br (45%) precluded meaningful comparisons between the two groups. Of patients completing RT as planned, 49% of patients (standard RT) versus 23% required an increase in posttreatment corticosteroid dosage (chi(2) test, P =.02). CONCLUSION: There is no difference in survival between patients receiving standard RT or short-course RT. In view of the similar KPS scores, decreased increment in corticosteroid requirement, and reduced treatment time, the abbreviated course of RT seems to be a reasonable treatment option for older patients with GBM.

Molecular cloning and genomic organization of the mouse AE2 anion exchanger gene.

The molecular organization of the AE2 (SLC4A2) gene, a member of the multigene family encoding sodium-independent chloride/bicarbonate anion exchangers, has previously been described in both humans and rats. In these two species, AE2 shows alternate promoter usages and tissue-specific expression of isoforms in a similar, but not identical, fashion. Here we report the molecular cloning and organization of the entire mouse AE2 gene. The gene consists of 23 exons and 22 introns and spans about 17 kb. Moreover, it drives transcription of N-terminal truncated isoforms from alternate promoter sequences in a way analogous to that described for rat and/or human orthologs. Thus, sequences within intron 2 function as overlapping alternate promoters for truncated isoforms AE2b(1) and AE2b(2), and sequences of intron 5 drive transcription of isoforms AE2c(1) and AE2c(2). Each of these variants has a specific alternative first exon, while remaining exons are common to the complete form of the message AE2a, the diversity at 5' leading to different N-termini in corresponding encoded proteins. As expected, mouse AE2 promoter sequences and the patterns of tissue expression of AE2 isoforms resemble rat counterparts more closely than human ones.

Single-arm, open-label phase II study of intravenously administered tirapazamine and radiation therapy for glioblastoma multiforme.

PURPOSE: This phase II study tested the efficacy and safety of tirapazamine (Sanofi Synthelabo Research, Malvern, PA), a bioreductive agent, in glioblastoma multiforme (GBM) patients. The patients were staged according to a model constructed by a recursive partitioning analysis (RPA) of glioma patients in prior Radiation Therapy Oncology Group (RTOG) trials and compared with a matched standard population, as predicted by the model. PATIENTS AND METHODS: A total of 124 patients diagnosed with a GBM were treated with radiation therapy and intravenous tirapazamine between January 27,1995, and April 25,1997. All patients received 60 Gy in 2-Gy fractions. Tirapazamine was delivered three times a week for 12 treatments during radiotherapy. Fifty-five patients received tirapazamine at 159 mg/m(2). A second dose level, 260 mg/m(2), was opened, and 69 patients were entered. RESULTS: There was no significant survival advantage to the drug in any RPA class at either dose level. The median survival time was 10.8 months for the patient population treated with the 159-mg/m(2) dose of tirapazamine and 9.5 months for the group treated with the 260-mg/m (2) dose of tirapazamine. Survival times by RPA class for patients receiving tirapazamine at 159 mg/m(2) were 27.4 months (class III), 10.8 months (class IV), 7.9 months (class V), and 3.8 months (class VI). Survival times by RPA class for patients receiving tirapazamine at 260 mg/m(2) were 16.2 months (class III), 10.3 months (class IV), 5. 1 months (class V), and 1.3 months (class VI). Patients in RPA class III treated in the 159 mg/m(2) dose arm had a notably longer survival than patients in the RTOG database RPA class III, but the difference did not reach statistical significance. There were no fatal toxicities. Grade 3/4 toxicities were more frequent at the higher dose level. CONCLUSION: Survival in the population treated with radiation and tirapazamine was equivalent to the control population. Patients in RPA class III treated with radiation and tirapazamine at the 159-mg/m(2) dose had a longer survival when compared with the historical controls. The improvement in survival did not reach statistical significance. Toxicity was acceptable in both treatment arms, but grade 3/4 toxicities were more frequent in the higher dose regimen.

A phase 3 randomized study of radiotherapy plus procarbazine, CCNU, and vincristine (PCV) with or without BUdR for the treatment of anaplastic astrocytoma: a preliminary report of RTOG 9404.

PURPOSE: This study was an open label, randomized Phase 3 trial in newly diagnosed patients with anaplastic glioma comparing radiotherapy plus adjuvant procarbazine, CCNU, and vincristine (PCV) chemotherapy with or without bromodeoxyuridine (BUdR) given as a 96-hour infusion each week of radiotherapy. METHODS AND MATERIALS: Only patients 18 years or older with newly diagnosed anaplastic glioma were eligible; central pathology review was accomplished, but was not mandated prior to registration. The study had initially opened as a Northern California Oncology Group (NCOG) trial in 1991, becoming an Intergroup RTOG, SWOG, and NCCTG study in July 1994. Total accrual of 293 patients was planned as the sample size, using survival and time to tumor progression as the primary endpoints. The experiment arm (RT/BUdR plus PCV) was to be compared to the control arm (RT plus PCV) using an alpha = 0.05, one-tailed, with a power of 85% for detecting an increase in median survival from 160 to 240 weeks, assuming a 3-year follow-up after completion of enrollment. RESULTS: As of July 1996, 281 patients had been randomized; 53 (20%) were ineligible, primarily based upon central pathology review, and another 39 cases were canceled. In total, 30% of cases were excluded from analysis. The treatment arms were well balanced despite this rate of exclusion. The RTOG Data Monitoring Committee recommended suspension of enrollment in July 1996 based upon a stochastic curtailment analysis which strongly suggested that the addition of BUdR would not be associated with increased survival. In February 1997, the study was closed prior to full enrollment. At that time, the 1-year survival estimates were 82% versus 68% for RT plus PCV and RT/BUdR plus PCV respectively (one-sided, p = 0.96). The conditional power analysis indicated that even with an additional 12 months of additional accrual and follow-up the probability of detecting the prespecified difference was less than 0.01%. The differences in the two arms seem to be due to early deaths in the BUdR arm, not related to toxicity of the treatment. CONCLUSIONS: Despite encouraging Phase 2 results with BUdR, it is unlikely that a survival benefit will be seen. A final study analysis will not be done for at least 3 more years.

Results of a phase III, double-blind, placebo-controlled trial of megestrol acetate modulation of P-glycoprotein-mediated drug resistance in the first-line management of small-cell lung carcinoma.

The objective of this study was to determine if the addition of megestrol acetate (MA), a modulator of P-glycoprotein-mediated drug resistance, to first-line cytotoxic therapy in patients with limited and advanced stage small-cell lung cancer (SCLC) would improve median time to disease progression and median overall survival. Secondary outcomes evaluated were response rates and patient symptom profile. Between 1992 and 1995, 130 eligible patients were randomized in a double-blind fashion to receive standard first-line therapy consisting of alternating courses of cyclophosphamide/doxorubicin/vincristine and etoposide/cisplatin (and thoracic radiotherapy for limited stage patients), along with either placebo or MA 160 mg t.i.d. for 8 days commencing 3 days before initiation of each cycle of chemotherapy. Treatment was continued for a maximum of six cycles. A total of 130 eligible patients were randomized, 65 to each arm. Fifty-two per cent of patients had limited disease and 48% had advanced disease. The median time to disease progression in limited stage disease was 46 weeks in the placebo arm and 43 weeks in the MA arm (P = 0.71) and in advanced stage disease was 28 weeks in the placebo arm and 27 weeks in the MA arm (P = 0.92). The median overall survival in limited stage disease was 75 weeks in the placebo arm and 75 weeks in the MA arm (P = 0.56) and in advanced stage disease was 41 weeks in the placebo arm and 39 weeks in the MA arm (P = 0.96). There was no consistent statistical difference in response rates or patient symptom profiles between the two treatment arms. The addition of MA, in the dose and schedule used, to standard first-line cytotoxic therapy in SCLC did not result in a significant improvement in response rates, symptom profile, median time to disease progression or overall survival.

Intervention with the hypoxic tumor cell sensitizer etanidazole in the combined modality treatment of limited stage small-cell lung cancer. A one-institution study.

PURPOSE: We report the toxicity, patterns of failure and survival of a cohort of patients with limited disease (LD) small-cell lung cancer (SCLC) treated with combined radiation and chemotherapy. During the course of thoracic irradiation, we added intravenous (i.v.) etanidazole (SR-2508, a third-generation 2-nitroimidazole) as a hypoxic cell sensitizer in an attempt to reduce the primary local failure rate and improve survival. METHODS AND MATERIALS: Between July 1988 and August 1990, 30 consecutive patients with limited disease SCLC were enrolled and treated on a Phase II protocol receiving a standard combination chemotherapy regimen utilizing i.v. cisplatin 25 mg/m2/day x 3 days, i.v. etoposide 100 mg/m2/day x 3 days alternating with intravenous cyclophosphamide 1000 mg/m2/day, intravenous doxorubicin 15 mg/m2, and intravenous vincristine 2 mg (CAV) to a total of six cycles every 3 weeks. Radiotherapy and etanidazole were started after the first cycle of chemotherapy. Etanidazole was administered intravenously at a dose of 2 g/m2 three times per week for a total of 30 g/m2 during the course of thoracic radiation that delivered 50.00 Gy tumor dose in 25 fractions in an overall time of 6 weeks. RESULTS: The overall response rate of the primary lesion in the thorax was 96% (CR + PR), with 64% complete responses. The median time to treatment failure was 18 months. Of the patients that have relapsed, only 18% failed in the thorax (alone or concomitant with other sites). This is a marked improvement compared to the 40-50% rate reported in the literature. The 2-year crude survival was 46%. The 3- and 5-year crude survival rate with no evidence of disease was 33 and 30%, respectively. We have observed a 10% increase in the incidence of transient etanidazole related peripheral neuropathies compared to previous etanidazole studies not utilizing systemic chemotherapy. There was no increased incidence of radiation esophagitis, pulmonary toxicity, or nephro- or myelotoxicity over and above what has been routinely observed with this radio/chemotherapy regimen. There were no treatment related deaths. CONCLUSION: The moderate increase in etanidazole-related transient peripheral neuropathies could have been related to the concomitant use of etanidazole with vincristine and cisplatin. Although the almost 50% improvement in the incidence of tumor failure rate in the thorax in this small group of patients did not correlate with an equal marked improvement in their survival, the 5-year survival outcome in our series is at least equal or better than the best reports in the literature of larger clinical trials. We believe there is sufficient data from this study, particularly the improvement of local tumor control, to warrant a large randomized controlled clinical trial, using the most current systemic chemotherapy with concomitant thoracic irradiation with or without the most effective available hypoxic cell cytotoxic/sensitizer.

Validation and predictive power of Radiation Therapy Oncology Group (RTOG) recursive partitioning analysis classes for malignant glioma patients: a report using RTOG 90-06.

PURPOSE: The recursive partitioning analysis (RPA) classes for malignant glioma patients were previously established using data on over 1500 patients entered on Radiation Therapy Oncology Group (RTOG) clinical trials. The purpose of the current analysis was to validate the RPA classes with a new dataset (RTOG 90-06), determine the predictive power of the RPA classes, and establish the usefulness of the database norms for the RPA classes. PATIENTS AND METHODS: There are six RPA classes for malignant glioma patients that comprise distinct groups of patients with significantly different survival outcome. RTOG 90-06 is a randomized Phase III study of 712 patients accrued from 1990 to 1994. The minimum potential follow-up is 18 months. The treatment arms were combined for the purpose of this analysis. There were 84, 13, 105, 240, 150, and 23 patients in the RPA Classes I-VI from RTOG 90-06, respectively. RESULTS: The median survival times (MST) and 2-year survival rates for the six RPA classes in RTOG 90-06 are compared to those previously published. The MST and 2-year survival rates for the RTOG RPA classes were within 95% confidence intervals of the 90-06 estimates for Classes I, III, IV, and V. The RPA classes explained 43% of the variation (squared error loss). By comparison, a Cox model explains 30% of the variation. The RPA classes within RTOG 90-06 are statistically distinct with all comparisons exceeding 0.0001, except those involving Class II. A survival analysis from a prior RTOG study indicated that 72.0 Gy had superior outcome to literature controls; analysis of this data by RPA classes indicates the survival results were not superior to the RTOG database norms. CONCLUSION: The validity of the model is verified by the reliability of the RPA classes to define distinct groups with respect to survival. Further evidence is given by prediction of MST and 2-year survival for all classes except Class II. The RPA classes explained a good portion of the variation in survival outcome in the data. Lack of correlation in RPA Class II between datasets may be an artifact of the small sample size or an indication that this class is not distinct. The validation of the RPA classes attests to their usefulness as historical controls for the comparison of future Phase II results.

Impact of adding concurrent chemotherapy to hyperfractionated radiotherapy for locally advanced non-small cell lung cancer (NSCLC): comparison of RTOG 83-11 and RTOG 91-06.

A hyperfractionated radiation therapy (HFX RT) trial (1.2 Gy twice daily, b.i.d.) (HFX) for non-small cell lung cancer (NSCLC) showed that 69.6 Gy resulted in better survival than did lower total doses (Radiation Therapy Oncology Group, RTOG 83-11) and that cisplatin concurrent with irradiation improved local control and survival over RT alone (Radiation Therapy Oncology Group, RTOG 91-06). Concurrent combination chemotherapy and HFX could improve both local and systemic control. In a phase II trial (RTOG 91-06) for inoperable NSCLC, two cycles of PE were used [cisplatin 50 mg/m2 intravenously (i.v.) days 1 and 8, etoposide 50 mg orally (p.o.) b.i.d., 75 mg/day if body surface area (BSA) < 1.7 m2, days 1-14] starting on day 1 of HFX (69.6 Gy) and repeated on day 29. HFX/PE was compared with HFX (69.6 Gy) from an earlier phase II trial (RTOG 83-11). Seventy-six patients treated with HFX/PE and 203 patients who received HFX alone were compared for toxicity, response, survival, and patterns of failure. The rates of grade 4 nonhematologic toxicity were similar (3.0% for HFX/PE, 3.0% for HFX), but grade 4 hematologic toxicity occurred only with HFX/PE 56.6%. Three (3.9%) HFX/PE patients had fatal toxicity (2 pulmonary, 1 renal); 1 HFX patient had fatal esophageal toxicity. Response and metastasis rates were similar for the two treatments, but infield (p = 0.054) and overall (p = 0.04) progression-free survival rates were better with HFX/PE. Median survivals were 18.9 months with HFX/PE and 10.6 months with HFX. Two-year survival rates were 36% for HFX/PE and 22% for HFX (p = 0.014). The differences in survival between HFX/PE and HFX remained borderline statistically significant (p = 0.0593) in the multivariate model, which included weight loss, Karnofsky performance status (KPS), sex, and stage. HFX/PE is an effective regimen in patients with inoperable NSCLC, although it is considerably more toxic, and is undergoing a comparison in a three-arm randomized phase III study against induction cisplatin/vinblastine plus standard once-daily RT and against cisplatin/vinblastine concurrent with standard RT.

Quality of life and neuropsychological evaluation for patients with malignant astrocytomas: RTOG 91-14. Radiation Therapy Oncology Group.

UNLABELLED: With increasingly aggressive neurosurgical and radiation therapy modalities (gamma knife, external beam stereotactic radiation and interstitial brachytherapy with or without hyperthermia) offered to patients with malignant astrocytomas (MA), increasing national demand for medical outcome studies and rising health care costs amidst public, business, and governmental debate to cut spending, we as physicians are obligated to continue our research to find effective treatments for malignant astrocytoma (MA) and a cost-effective means to study their impact upon the patient's quality of life (QOL). PURPOSE: We report data that was collected within the Radiation Therapy Oncology Group (RTOG) on 126 patients with MA who were enrolled in RTOG 91-14. This study was undertaken to prospectively test the feasibility of performing quality of life (QOL) and neuropsychological evaluation (NPE) and collecting this data within the RTOG. RESULTS: The NPE and QOL parameters that were used in this study are cost effective. They are not only much cheaper than formal cognitive and memory testing, but also provide additional information regarding the patients' day to day functional abilities that are not provided by the current routinely used means, such as KPS. The Mini-Mental Status Exam (MMSE) provides greater sensitivity to patients' differences in neurological status and may be preferable to NFS as an eligibility criteria.

Survival improvement in anaplastic astrocytoma, combining external radiation with halogenated pyrimidines: final report of RTOG 86-12, Phase I-II study.

PURPOSE: This study evaluated the toxicity and tumor efficacy of the halopyrimidine IUdR as a chemical modifier of radiation response in patients with malignant glioma. The preliminary results published in 1993 demonstrated no real advantage in the group of patients with glioblastoma. However, a benefit appeared to be evolving in the group of patients with Anaplastic Astrocytoma (AA). We are now presenting the results on the long-term follow-up of patients with AA. METHODS AND MATERIALS: Between August 1987 and October 1991, 79 patients were entered in a prospective study with newly diagnosed malignant glioma. Twenty-one of 79 were AA. The study was designed to have a fixed dose of radiation consisting of 60.16 Gy in 32 fractions in 6.5 weeks but varying the dose schedule of IUdR, delivered in a continuous intravenous infusion of long (96 h) or short (48 and 24 h) duration, every week for the 6.5 weeks of radiation treatment. RESULTS: The last AA patient was entered in March 1991. Ninety-five percent of the AA patients were under 59 years of age and 86% had a Karnofsky score 80. Thirty-eight percent had a tumor diameter of less than 5 cm and 52% had a tumor diameter between 5-10 cm. Seventy-six percent had partial or total tumor resection. The toxicity of this treatment was acceptable and has already been published elsewhere. At the time of this report, 14 out of 21 patients with AA are dead. The median survival, calculated from the Kaplan-Meier, is 3.2 years. Thirty-three percent of the patients have survived 5 years. These results compare favorably with the best results reported in the literature with postoperative external radiation plus chemotherapy, median survival time (MST) of 3 years, and previous Radiation Therapy Oncology Group (RTOG) experience with radiation alone, MST of 2 years. CONCLUSIONS: Our findings in patients with AA corroborate the improved therapeutic results published recently when combining external radiation with "long" infusion of i.v. BUdR and indicate the need to proceed with randomized Phase III studies utilizing halogenated pyrimidines and radiation. One such study has already been activated, RTOG # 94-04.

Measurement of hypoxia in human tumours by non-invasive spect imaging of iodoazomycin arabinoside.

Tumour oxygenation status in individual patients may be assessed using the bioreduction and linkage of 2-nitroimidazole markers to viable hypoxic cells in vivo with subsequent detection by conventional nuclear medicine techniques. Iodoazomycin arabinoside (IAZA) was radiolabelled with Iodine-123 and administered i.v. to 51 patients with newly diagnosed malignancies whose tumours were subsequently imaged by planar and single-photon emission computed tomographic (SPECT) procedures. Quantitative analyses of radiotracer avidity were performed at 24 h post-injection and tumour-normal tissue ratios of greater than 1.10 were deemed positive for tumour hypoxia. By this criterion, the frequencies of hypoxia in small-cell lung cancer, squamous cell carcinomas of head and neck and malignant gliomas were 60% (9/15), 40% (6/15) and 0% (0/11) respectively. The correlation of positive IAZA scans with tumour control and survival in patients with lung cancer and head and neck tumours is currently under study. Preliminary observations in neck metastases from squamous cell carcinoma of head and neck tumours indicates decreased local control at 3 months post-treatment in tumours with IAZA avidity. This study concludes that: (1) 123I-IAZA can be administered safely and repeatedly as an outpatient routine imaging procedure in cancer patients during initial work-up and follow-up; (2) that retained drug can be detected by conventional nuclear medicine procedures in inaccessible deep-seated tumours; and (3) that this technique could prove useful for identifying those patients for whom hypoxia-directed therapy is indicated.

Phase II study of prolonged oral therapy with etoposide (VP16) for patients with recurrent malignant glioma.

Because the percentage of dividing cells in malignant gliomas is small, cell cycle specific drugs such as VP16 are most effective if given continuously over prolonged periods. In this study, we chose a dose of 50 mg/day to minimize therapy interruptions for myelosuppression. VP16 was given until the neutrophil count dropped to < 1.0 x 10(9)/L or the platelets fell to < 75 x 10(9)/L and resumed when the counts rose to normal levels. We treated 46 patients with supratentorial malignant glioma (15 anaplastic astrocytoma, 21 glioblastoma multiforme, 9 anaplastic oligodendroglioma, 1 undifferentiated primary malignant brain tumor) at the time of tumor progression. All had KPS > or = 70 at study entry. All patients had prior RT, 13 with adjuvant nitrosourea. Twenty-four had prior nitrosourea chemotherapy for tumor progression, 7 had no prior chemotherapy. We treated 20 patients with VP16 at first progression and 26 at second or later progression. All patients had CT or MR scans and clinical evaluation every 8 weeks. Median time to tumor progression (TTP) was 8.8 weeks for all evaluable patients, 8.6 weeks for those treated at first progression and 8.4 weeks for those treated at second progression, 9.1 weeks for anaplastic astrocytoma, 7.5 weeks for glioblastoma multiforme and 17.1 weeks for anaplastic oligodendroglioma. There were 8 responses and 11 patients with stable disease for at least 8 weeks (R + SD = 42%). Prolonged low-dose oral VP15 is well tolerated, with minimal myelosuppression. Prolonged low-dose oral VP16 is modestly effective treatment for patients with recurrent malignant glioma and is more effective for anaplastic astrocytoma and anaplastic oligodendroglioma than glioblastoma multiforme.

Iododeoxyuridine (IUdR) combined with radiation in the treatment of malignant glioma: a comparison of short versus long intravenous dose schedules (RTOG 86-12).

PURPOSE: To evaluate the toxicity and tumor efficacy of the halopyrimidine IUdR (NSC #39661, IND 22475) as a chemical modifier of radiation response when used in a high dose short time infusion versus the acceptable 4 day infusion. METHODS AND MATERIALS: In August 1987 we initiated a prospective study in patients with newly diagnosed anaplastic astrocytoma and glioblastoma. The study was designed to have a fixed dose of radiation (60.16 Gy = 1.88 Gy in 32 fractions in 6.5 weeks) but varying the dose schedule of IUdR, keeping the total dose between 21 and 24 g/m2. IUdR was delivered in a 96, 48, or 24 hr continuous intravenous infusion per week for 6.5 weeks during radiation treatment. RESULTS: The study was closed for patient accrual on October 1, 1991. Twenty-two patients were treated on the 96 hrs, 32 on the 48 hr and 25 on the 24 hr schedules. The incidence of glioblastoma ranged between 68 and 75% in the three arms. Seventy percent of the patients had a Karnofsky of 80-90% at the onset of treatment. Over 50% of the patient population were under age 55. Drug tolerance was related to the duration of the IUdR infusion. Toxicities were most pronounced in the 96 hr IUdR infusion schedule where 27.4% of the patients reported a grade 3 drug toxicity. No fatal or grade 4 toxicities were observed. More patients on the 24 and 48 hr schedule received at least 80% of the IUdR dose specified per protocol. We did not observe a trend in acute normal tissue radiation reactions in any of the three arms. The median survivals calculated from the Kaplan-Meier plot are 13.4, 10.5, and 11 months, respectively, for the 96, 48, and 24 hr infusions. The Cox Proportional Hazards model showed that any difference in survival can be attributed to histological grade, type of previous surgery and, to some extent, age of the patient. Dose schedule was not a significant predictor of survival, although statistically nonsignificant trend toward longer survival is seen in those patients with glioblastoma treated in the "long" 4 day schedule. CONCLUSION: Overall, our treatment combination, particularly for patients with glioblastoma, has not shown convincing evidence of an improvement in survival. Of interest, however, it is the 2 year survival rate of 68% for patients with anaplastic astrocytoma. In our experience, the administration of IUdR is laborious, time consuming and with bothersome acute gastrointestinal and hematological toxicities.

Imaging tumor hypoxia and tumor perfusion.

Tumor perfusion and oxygenation status have been suggested as factors which may influence treatment outcome in cancer patients. Nuclear medicine assays of tumor perfusion [99mTc-hexamethylpropylenamine oxime (HMPAO)] and tumor hypoxia [123I-iodoazomycin arabinoside (IAZA)] have recently been developed and described. We report on measurements of perfusion and oxygenation status of 27 tumors in 22 patients using these probes. An inverse correlation between tumor uptake of HMPAO and IAZA was measured (p < 0.05), with severe perfusion deficit usually associated with an increased uptake of the hypoxic marker. This trend was observed for limited stage small-cell lung carcinoma, squamous-cell carcinoma of the head and neck, soft-tissue sarcoma, brain metastases from small-cell lung carcinoma and adenocarcinoma of the prostate as a group, but not for glioblastoma multiforme. Whereas each imaging agent can yield information about the physiological status of tumor and normal tissue, the information resulting from their combined use could be important in cancer therapy.

The effect of radiation on normal human CNS as detected by NMR spectroscopy.

In a prospective study, proton (1H) and phosphorus (31P) nuclear magnetic resonance spectroscopy were used to search for effects of brain tumor radiotherapy on normal human central nervous system. Phosphorus spectroscopy data at 1.5 T seems to suggest that any radiation induced damage that may occur as a result of therapeutic brain irradiation, does not alter the relative concentrations of phosphorus metabolites or the intracellular pH beyond the limits of normal variation (approximately +/- 20%). Proton spectroscopy, on the other hand, detects post radiation changes in the ratios of certain nuclear magnetic resonance visible metabolites following radiotherapy, particularly choline/N-acetylaspartate, and especially in regions of brain receiving high doses of radiation. Such changes may be indicative of the release of membrane bound choline during radiation induced demyelination of brain. Of interest, we have found elevated metabolite ratios of 31P in normal central nervous system prior to radiotherapy, which persisted throughout the time span of the study in both the ipsilateral and contralateral cerebral hemispheres.