A phase II study of temozolomide vs. procarbazine in patients with glioblastoma multiforme at first relapse

A randomized, multicentre, open-label, phase II study compared temozolomide (TMZ), an oral second-generation alkylating agent, and procarbazine (PCB) in 225 patients with glioblastoma multiforme at first relapse. Primary objectives were to determine progression-free survival (PFS) at 6 months and safety for TMZ and PCB in adult patients who failed conventional treatment. Secondary objectives were to assess overall survival and health-related quality of life (HRQL). TMZ was given orally at 200 mg/m(2)/day or 150 mg/m(2)/day (prior chemotherapy) for 5 days, repeated every 28 days. PCB was given orally at 150 mg/m(2)/day or 125 mg/m(2)/day (prior chemotherapy) for 28 days, repeated every 56 days. HRQL was assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30 [+3]) and the Brain Cancer Module 20 (BCM20). The 6-month PFS rate for patients who received TMZ was 21%, which met the protocol objective. The 6-month PFS rate for those who received PCB was 8% (P = 0.008, for the comparison). Overall PFS significantly improved with TMZ, with a median PFS of 12.4 weeks in the TMZ group and 8.32 weeks in the PCB group (P = 0.0063). The 6-month overall survival rate for TMZ patients was 60% vs. 44% for PCB patients (P = 0.019). Freedom from disease progression was associated with maintenance of HRQL, regardless of treatment received. TMZ had an acceptable safety profile; most adverse events were mild or moderate in severity.

Randomized trial of three chemotherapy regimens and two radiotherapy regimens and two radiotherapy regimens in postoperative treatment of malignant glioma. Brain Tumor Cooperative Group Trial 8001

Within 3 weeks of definitive surgery, 571 adult patients with histologically confirmed, supratentorial malignant gliomas were randomly assigned to receive one of three chemotherapy regimens: BCNU (1,3-bis(2-chloroethyl)-1-nitrosourea) alone, alternating courses (every 8 weeks) of BCNU and procarbazine, or BCNU plus hydroxyurea alternating with procarbazine plus VM-26 (epipodophyllotoxin). Patients accrued in 1980 and 1981 were to receive 6020 rads of whole-brain radiotherapy concurrent with the first course of chemotherapy. Patients accrued in 1982 and 1983 were randomly assigned to receive either whole-brain irradiation as above, or 4300 rads of whole-brain radiotherapy plus 1720 rads coned down to to the tumor volume. The data were analyzed for the total randomized population and separately for the 510 patients, termed the "Valid Study Group (VSG)," who met protocol eligibility specifications (including central pathology review), 80% of whom had glioblastoma multiforme. The median survival times from time of randomization for the three chemotherapy groups of the VSG ranged from 11.3 to 13.8 months, and 29% to 37% of the patients survived for 18 months (life-table estimate); the differences between these groups were not statistically significant. Survival differences between the radiotherapy groups were small and not statistically significant. It is concluded that, for malignant glioma, giving part of the radiotherapy by coned-down boost is as effective as full whole-brain irradiation, and that multiple-drug chemotherapy as outlined in this protocol conferred no significant survival advantage over BCNU alone.

Cellular-telephone use and brain tumors

BACKGROUND

Concern has arisen that the use of hand-held cellular telephones might cause brain tumors. If such a risk does exist, the matter would be of considerable public health importance, given the rapid increase worldwide in the use of these devices.

METHODS

We examined the use of cellular telephones in a case-control study of intracranial tumors of the nervous system conducted between 1994 and 1998. We enrolled 782 patients through hospitals in Phoenix, Arizona; Boston; and Pittsburgh; 489 had histologically confirmed glioma, 197 had meningioma, and 96 had acoustic neuroma. The 799 controls were patients admitted to the same hospitals as the patients with brain tumors for a variety of nonmalignant conditions.

RESULTS

As compared with never, or very rarely, having used a cellular telephone, the relative risks associated with a cumulative use of a cellular telephone for more than 100 hours were 0.9 for glioma (95 percent confidence interval, 0.5 to 1.6), 0.7 for meningioma (95 percent confidence interval, 0.3 to 1.7), 1.4 for acoustic neuroma (95 percent confidence interval, 0.6 to 3.5), and 1.0 for all types of tumors combined (95 percent confidence interval, 0.6 to 1.5). There was no evidence that the risks were higher among persons who used cellular telephones for 60 or more minutes per day or regularly for five or more years. Tumors did not occur disproportionately often on the side of head on which the telephone was typically used.

CONCLUSIONS

These data do not support the hypothesis that the recent use of hand-held cellular telephones causes brain tumors, but they are not sufficient to evaluate the risks among long-term, heavy users and for potentially long induction periods.

A randomized comparison of intra-arterial versus intravenous BCNU, with or without intravenous 5-fluorouracil, for newly diagnosed patients with malignant glioma

This Phase III trial tested the efficacy and safety of intra-arterial 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) for the treatment of newly resected malignant glioma, comparing intra-arterial BCNU and intravenous BCNU (200 mg/sq m every 8 weeks), each regimen without or with intravenous 5-fluorouracil (1 gm/sq m three times daily given 2 weeks after BCNU). All patients also received radiation therapy. A total of 505 patients were randomly assigned within the study. Fifty-seven patients were excluded, primarily because of neuropathology error, and the remaining 448 patients constituted the Valid Study Group. Of the total 505 patients, 190 patients could not receive intra-arterial BCNU and 315 patients were randomly assigned to receive intra-arterial (167 patients) and intravenous (148 patients) BCNU. Actuarial analysis (log-rank) demonstrated reduced survival for the intra-arterial group (p = 0.03). Serious toxicity was observed in the intra-arterial group; 16 patients (9.5%) developed irreversible encephalopathy with computerized tomography evidence of cerebral edema, and 26 patients (15.5%) developed visual loss ipsilateral to the infused carotid artery. Administration of 5-fluorouracil did not influence survival. The survival rate between the intravenous and the intra-arterial BCNU patients with glioblastoma multiforme did not differ, but was worse for intra-arterial BCNU patients with anaplastic astrocytoma than for those receiving intravenous BCNU (p = 0.002). Neuropathologically, intra-arterial BCNU produced white matter necrosis. It is concluded that intra-arterial BCNU is neither safe nor effective in prolonging survival when administered by the methods used in this study of newly diagnosed patients with malignant glioma.

Prediction of BCNU pulmonary toxicity in patients with malignant gliomas: an assessment of risk factors

Symptomatic pulmonary disease occurred in 20 per cent of 93 patients with anaplastic gliomas being treated with carmustine (BCNU). An analysis of the variables has revealed a relation between the occurrence of pulmonary toxicity on the one hand, and the total cumulative dose of BCNU, the number of cycles over which the BCNU was administered, the history of lung disease, the patient's age, and the platelet-count nadir after the first course of BCNU on the other. An equation has been generated that allows prediction of pulmonary toxicity during the course of therapy with BCNU with 80 per cent accuracy. Pretreatment analysis of individual cases should allow safe use of BCNU and prevention of most of the serious pulmonary complications caused by this drug.

Results of a randomized trial comparing BCNU plus radiotherapy, streptozotocin plus radiotherapy, BCNU plus hyperfractionated radiotherapy, and BCNU following misonidazole plus radiotherapy in the postoperative treatment of malignant glioma

In Brain Tumor Cooperative Group Study 77-02, eleven institutions randomized 603 adult patients with supratentorial malignant glioma to one of four treatment groups following surgery: conventional radiotherapy (6000 cGy in 30-35 fractions) + BCNU, conventional radiotherapy + streptozotocin, hyperfractionated (twice daily) radiotherapy (6600 cGy in 60 fractions) + BCNU, and conventional radiotherapy with misonidazole followed by BCNU. Data were analyzed for the total randomized population and for the 557 patients (86% with glioblastoma multiforme) who met protocol eligibility specifications (including confirmed histopathology on central review). Median survival was approximately 10 months following randomization. Overall there was no statistically significant difference in survival among the four groups. Among non-glioblastoma patients, the misonidazole group appeared to have poor survival. Peripheral neuropathy was a dose-limiting toxicity with misonidazole. It is concluded that neither the addition of misonidazole nor hyperfractionated radiotherapy as given in this protocol offered any advantage over conventional radiotherapy plus either BCNU or streptozotocin for treatment of malignant glioma.

Brain stem and spinal metastases of supratentorial glioblastoma multiforme: a clinical series

Although the spread of supratentorial glioblastoma multiforme to the brain stem and spine has been extensively described in published autopsy series, information on the diagnosis, treatment, and subsequent clinical course of patients manifesting symptoms of glioblastomatous dissemination ante mortem remains scant. We report a series of 11 patients having the signs and symptoms of neuraxis dissemination of supratentorial glioblastoma multiforme. All patients had radiographic documentation of metastases by either contrast-enhanced myelograms or enhanced magnetic resonance imaging scans. Ten presented with spinal involvement, whereas one presented with lower cranial neuropathies secondary to diffuse involvement of the basal cisterns. The mean age of the patients was 38.5 years, and the mean time interval between diagnosis of intracranial disease and diagnosis of metastases was 14.1 months. After diagnosis of tumor spread, subsequent mean survival time was 2.8 months. All patients received additional radiotherapy to the areas of metastasis, but the clinical response to radiotherapy was quite poor. This study confirms previous reports in the literature suggesting that metastases occur in younger patients and in patients with extended survival. The findings suggest that the relatively infrequent clinical incidence of the symptomatic spread of glioblastoma multiforme, as compared with the frequent incidental discovery of such spread at autopsy, may be the result of the limited survival of the affected patients, and not due to the biology of the tumor.

Response of low-passage human malignant gliomas in vitro to stimulation and selective inhibition of growth factor-mediated pathways

The proliferation of many nonglial tumors in vitro depends on the presence of nanomolar concentrations of one or more growth factors. To define the growth factor requirements of malignant glial tumors, the authors examined the response properties of four low-passage human malignant glioma lines to the following mitogens: epidermal growth factor (EGF), acidic and basic fibroblast growth factors (FGF's), insulin-like growth factor I (IGF-I), nerve growth factor (NGF), platelet-derived growth factor (PDGF), 12-O-tetradecanoyl-13-phorbol acetate (TPA), and serum. Each of the tumors showed increased deoxyribonucleic acid (DNA) synthesis (assessed by acid-precipitable [3H]-thymidine incorporation) in response to PDGF with a maximum effect at 50 ng/ml. Three tumors responded to EGF, three to IGF-I, two to acidic FGF, two to basic FGF, and two to TPA with maximum effects at 10, 50, 1, 1, and 10 ng/ml, respectively. None of the tumors responded to NGF. In the responsive tumors, optimum concentrations of EGF, IGF, TPA, acidic FGF, and basic FGF induced, at most, a two- to fourfold increase in [3H]-thymidine incorporation, which was only 30% to 50% of the response seen in 10% serum. In contrast, PDGF increased DNA synthesis eight- to 10-fold, equaling the effect of 10% serum. Measurements of cell proliferation also demonstrated a significant response to PDGF in each of the tumors. Appropriate concentrations of an anti-PDGF neutralizing antibody inhibited baseline DNA synthesis and proliferation in the absence of added growth factors, suggesting the possible role of PDGF in autocrine stimulation of these cells. However, this antibody produced only slight inhibition of serum-induced mitogenesis. Trapidil, an agent reported to inhibit the effects of PDGF, and polymyxin B, an inhibitor of protein kinase C, strongly inhibited baseline as well as PDGF- and serum-induced mitogenesis. It is concluded that, in the malignant gliomas studied, PDGF may be acting as a dominant mitogen to enhance DNA synthesis, and may function in autocrine stimulation. However, other factors contained in serum can also contribute to cell division.

Survival of patients with well-differentiated astrocytomas diagnosed in the era of computed tomography

We report 25 verified cases of well-differentiated cerebral astrocytomas in adults treated between 1978 and 1988. All patients were diagnosed by computed tomographic (CT) scans, with 5 undergoing a craniotomy for debulking and 20 undergoing a biopsy alone. The median survival for the entire group was 8.2 years, the longest survival yet reported for a series of patients with these tumors. A review of the literature suggests that the longer survival observed in more recent series is the result of the earlier diagnosis of tumors afforded by modern brain imaging. Twenty of our patients presented with seizures in the absence of any other focal findings and would probably not have had a biopsy in the era before CT scans until their tumors had progressed. Only 8% of our patients had papilledema at the time of presentation, in contrast to almost half of the patients with low-grade astrocytomas reported before 1975, supporting the hypothesis that patients in the CT era are diagnosed earlier. None of our patients died from progressive low-grade disease. One patient died from a squamous cell cancer, and 7 died as a consequence of their tumors dedifferentiating into a more malignant astrocytoma or glioblastoma multiforme, with a median time of approximately 5 years after the diagnosis. Our findings, together with the available data in the literature, suggest that death from a focal low-grade astrocytoma, in the absence of malignant degeneration, may be a rare event. Consequently, future therapeutic efforts should be targeted at preventing dedifferentiation.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunobiology of primary intracranial tumors. Part 10: Therapeutic efficacy of interferon in the treatment of recurrent gliomas

Human lymphoblastoid alpha-interferon was administered intravenously or intramuscularly to 19 patients with recurrent gliomas. Each patient had previously undergone surgery and radiation therapy. The treatment course consisted of 8 weeks of therapy with an escalating daily dosage and number of days of treatment per week to a total dose of 900 X 10(6) U/sq m. Response to treatment was determined by serial computerized tomography (CT) scans. Seven of the 17 evaluable patients were determined to be treatment responders at 12 weeks (1 month after completion of treatment), and the other 10 patients exhibited tumor progression during this period. Median survival time was 511 days for the responders versus 147 days for the non-responding patients. Interferon appears to be efficacious in the treatment of recurrent anaplastic gliomas as defined by CT brain scan responses following therapy.

Intracranial pencil injuries

A case of delayed central nervous system manifestations of intracranial penetration by a pencil is presented. Twenty-one additional cases of cerebral injury by pencils are reviewed and discussed. A high index of suspicion, liberal use of the computed tomographic scan, and early operative intervention in cases with cranial perforation are important points in the management of these injuries.

Season of birth and risk of brain tumors in adults

BACKGROUND

Recent studies demonstrated an excess of winter births in children with brain tumors and in adults with various neurologic or psychiatric diseases relative to the general population.

OBJECTIVE

To investigate a possible association between month of birth and risk of brain tumors in adults using data from a large, hospital-based case-control study.

METHODS

Cases were patients with incident glioma (n = 489) or meningioma (n = 197) diagnosed at hospitals in Boston, MA, Phoenix, AZ, and Pittsburgh, PA. Controls (n = 799) were patients hospitalized for a variety of nonmalignant conditions and frequency matched to cases by hospital, age, sex, race/ethnicity, and distance of residence from hospital. Odds ratios (ORs) were calculated using multivariate unconditional logistic regression allowing for cyclic variation in risk with month of birth.

RESULTS

A relationship between month of birth and risk of adult glioma and meningioma was found, best described by a 12-month periodic function with peaks in February and January and troughs in August and July. The association between month of birth and risk of glioma differed significantly by handedness, with left-handed and ambidextrous subjects born during late fall through early spring being at particularly high risk of adult glioma as compared with those born at other times of the year.

CONCLUSION

These findings suggest the importance of seasonally varying exposures during the pre- or postnatal period in the development of brain tumors in adults.

Response of malignant glioma cell lines to activation and inhibition of protein kinase C-mediated pathways

To evaluate the role of protein kinase C-mediated pathways in the proliferation of malignant gliomas, this study examined the effect of a protein kinase C (PKC)-activating phorbol ester (12-O-tetradecanoyl-13-phorbol acetate or TPA) and a protein kinase C inhibitor (polymyxin B) on deoxyribonucleic acid (DNA) synthesis of malignant glioma cells in vitro. A serum-free chemically defined medium, MCDB 105, was employed for all studies. Two established human malignant glioma cell lines (T98G and U138), two rat glioma lines (9L and C6), and two low-passage human glioma lines (obtained from surgical specimens) were studied. With the exception of the C6 line, all tumors responded in a dose-dependent fashion to nanomolar concentrations of TPA with a median effective dose that varied from 0.5 ng/ml for the U138 glioma to 1 ng/ml for the T98G glioma. At optimal concentrations (5 to 10 ng/ml), TPA produced a two- to five-fold increase in the rate of DNA synthesis (p less than 0.05) as assessed by incorporation of 3H-thymidine. However, TPA had no additive effect on the mitogenic response produced by epidermal growth factor (EGF) or platelet-derived growth factor (PDGF). Inhibition of PKC using the antibiotic polymyxin B (20 micrograms/ml) abolished the TPA-induced mitogenic response in the five responsive lines tested. In two tumors (U138 and 9L), polymyxin B also eliminated EGF-, PDGF-, and serum-induced DNA synthesis as well as abolishing baseline DNA synthesis. These cells remained viable, however, as assessed by trypan blue exclusion; after removal of polymyxin B from the medium, they were able to resume DNA synthesis in response to TPA and serum. In the three other tumors (T98G and the two low-passage human glioma lines), growth factor-induced and serum-induced DNA synthesis were inhibited by approximately 25% to 85%. It is concluded that PKC-mediated pathways affect DNA synthesis in the human malignant glial tumors studied. The response of the glioma cells to TPA is similar to the responses seen in fetal astrocytes, but differs significantly from those reported for normal adult glial cultures. Because the response of the 9L glioma to TPA is similar to the responses seen in the human tumors, the 9L rat glioma model may prove useful for examining the role of PKC-mediated pathways in controlling glioma growth in vivo.

Response of malignant glioma cell lines to epidermal growth factor and platelet-derived growth factor in a serum-free medium

The use of a serum-free culture system for assessing the growth factor responsiveness of malignant glial cells is described. The mitogenic properties of epidermal growth factor (EGF) and platelet-derived growth factor (PDGF) were examined in three human malignant glioma cell lines (T98G, U87, and U138). Each of the three had high-affinity EGF receptors and all responded in a dose-dependent fashion to physiological concentrations of EGF. These cell lines also showed a pronounced mitogenic response to PDGF which equaled or exceeded that achieved with EGF. Simultaneous stimulation with both factors produced an additive response, which approximated that obtained in medium supplemented with 10% fetal calf serum. The authors conclude that functional EGF and PDGF receptors were present in the human malignant glial tumors studied. The response of the human glioma lines to these growth factors in many respects parallels the response seen in fetal astrocytes tested under similar conditions. In contrast, the behavior of two chemically induced rat gliomas (9L and C6) differed significantly from that seen in the human lines, suggesting that the rat lines may not be entirely acceptable as models for studying the growth characteristics of human malignant glial tumors.

The treatment of intracranial malignant gliomas using orally administered tamoxifen therapy: preliminary results in a series of "failed" patients

In vitro studies have shown that the nonsteroidal antiestrogen tamoxifen can suppress deoxyribonucleic acid synthesis and cell proliferation in cultured human gliomas. This growth suppression is independent of its antiestrogenic properties. Tamoxifen may act through the inhibition of the enzyme protein kinase C, which transduces mitogenic signals from the cell surface to the nucleus. Based on these preclinical studies, we initiated a clinical trial of orally administered tamoxifen, 20 mg twice daily, to patients with recurrent, progressive malignant gliomas who were not candidates for other "failed" protocols, such as brachytherapy. No limits were placed on age, Karnofsky Performance Score (KPS), or expected survival. Thirty-two patients were entered in the study, 29 with a glioblastoma multiforme and 3 with an anaplastic astrocytoma. The mean age of the group was 48 years, and the mean KPS was 65. Median survival of the entire cohort from the onset of tamoxifen therapy was 17 weeks; the median survival of those patients with an initial KPS of 70 or more was 21 weeks. Seven patients survived for more than 6 months with no change in their baseline computed tomographic scans or KPS on tamoxifen, including 2 patients with computed tomographic evidence of regression during the course of therapy. There were no significant patient-reported side effects of the treatment. Three patients had thromboembolic complications during tamoxifen administration. We conclude that tamoxifen can be administered safely to these patients and may show some efficacy against glial neoplasms.

Occupation and the risk of adult glioma in the United States

OBJECTIVE

Previous studies have observed increased glioma incidence associated with employment in the petroleum and electrical industries, and in farming. Several other occupations have also been associated with increased risk, but with inconsistent results. We evaluated associations between occupational title and glioma incidence in adults.

METHODS

Cases were 489 patients with glioma diagnosed from 1994 to 1998 at three United States hospitals. Controls were 799 patients admitted to the same hospitals for non-malignant conditions. An experienced industrial hygienist grouped occupations that were expected to have similar tasks and exposures. The risk of adult glioma was evaluated for those subjects who ever worked in an occupational group for at least six months, those who worked longer than five years in the occupation, and those with more than ten years latency since starting work in the occupation.

RESULTS

Several occupational groups were associated with increased glioma incidence for having ever worked in the occupation, including butchers and meat cutters (odds ratio [OR] = 2.4; 95% confidence limits [CL]: 1.0, 6.0), computer programmers and analysts (OR = 2.0; 95% CL: 1.0, 3.8), electricians (OR = 1.8; 95% CL: 0.8, 4.1), general farmers and farmworkers (OR = 2.5; 95% CL: 1.4, 4.7), inspectors, checkers, examiners, graders, and testers (OR = 1.5; 95% CL: 0.8, 2.7), investigators, examiners, adjustors, and appraisers (OR = 1.7; 95% CL: 0.8, 3.7), physicians and physician assistants (OR = 2.4; 95% CL: 0.8, 7.2), and store managers (OR = 1.6; 95% CL: 0.8, 3.1), whereas occupation as a childcare worker was associated with decreased glioma incidence (OR = 0.4; 95% CL: 0.2, 0.9). These associations generally persisted when the subjects worked longer than five years in the occupation, and for those with more than ten years latency since starting to work in the occupation.

CONCLUSIONS

This is our first analysis of occupation and will guide future exposure-specific assessments.

1,3-Bis(2-chloroethyl)-1-nitrosourea (BCNU)-induced pulmonary fibrosis

Clinical data are presented on 14 patients undergoing BCNU therapy for a primary intracranial glioma (11 biopsied, 3 suspected) in whom pulmonary fibrosis developed as a consequence of the therapy. Pulmonary diffusion abnormalities, dry hacking cough, and chest x-ray changes herald the onset of the process. Microscopic evaluation of lung specimens revealed a wide spectrum of change including hyaline membrane formation, alveolar septal thickening, interstitial fibrosis, and granuloma formation. It is concluded that BCNU causes pulmonary fibrosis that is primarily but not necessarily dose-related and may not be reversible.

Long-term survival after the diagnosis of malignant glioma: a series of 22 patients surviving more than 4 years after diagnosis

Long-term survival after the diagnosis of malignant glioma is uncommon but not rare. To define better the population of patients who have extended survival with this disease, we reviewed the records of 22 of our patients who survived more than 4 years after the biopsy-proven diagnosis of anaplastic astrocytoma, malignant mixed glioma, or glioblastoma multiforme. Surprisingly, 21 of the 22 patients are still alive and being actively followed by the authors. The long-term survivors were typically young and with minimal or no functional impairment at the time of diagnosis. Survivals ranged from 4.2 to 15.8 years. The quality of survival was generally good, with the surviving patients having a mean Karnofsky Performance Score of 76. Three-quarters of the patients had no enhancement or mass effect on their most recent computed tomography scans. A review of the available literature, together with our own series, suggests that death from recurrent disease is unusual in glioma patients who survive more than 4 or 5 years.

Correlation of thallium-201 single photon emission computed tomography and survival after treatment failure in patients with glioblastoma multiforme

After initial radiotherapy for an intracranial malignant glioma, the majority of patients return at a later date with a recurrent, enhancing mass on computed tomography or magnetic resonance imaging. This mass represents either recurrent tumor, radionecrosis, or a combination of the two. The relative proportion of live versus dead tumor cells is difficult to determine from surgical specimens of another biopsy, although this has been the preferred method of assessing such "failed" patients. Recently, attention has turned to tomographic images of metabolic markers, i.e., positron emission tomography and thallium-201 (Tl-201) single photon emission computed tomography, as noninvasive methods of assessing relative tumor viability. To assess whether Tl-201 uptake in vivo can be used as a prognostic indicator in patients with glioblastoma multiforme, we measured the ratio of Tl-201 uptake in tumor to Tl-201 uptake in myocardium (T/C ratio) in 16 patients at the point of treatment "failure" and followed all the patients until they died. All patients died of neurological causes, and 11 of the 16 patients had documented viable tumor recurrence. There was a significant negative correlation between the T/C ratio at failure and the time interval between failure and death (r = -0.602, P = 0.014). Patients with T/C ratios of less than 0.3 lived an average of 13 months, whereas patients with T/C ratios of more than 0.3 lived an average of only 4 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Pathological correlation of CT ring in recurrent, previously treated gliomas

The meaning of the enhancing ring commonly seen on computerized tomographic (CT) scans in patients with recurrent, treated glioblastoma has long been of concern. Does the ring represent radiation necrosis, pseudocapsule formation, compressed adjacent brain, or, in fact, a peripheral zone of viable tumor? We employed a multiple intratumoral biopsy technique at the time of reoperation to investigate this ring. Pathological evidence is presented documenting the content of the ring to the viable tumor. It is suggested that perhaps treatment failure may be determined on sequential CT examinations by comparing the volume and degree of contrast enhancement.

Brain-tumor cell kinetics correlated with survival

In a review of 38 glioblastoma patients for whom fresh tissue kinetic data were available before any therapy was instituted, no correlation between the labeling index and survival time could be statistically determined. This relationship seems entirely consistent with the published theoretical determinants of tumor behavior: that is, altered ability for growth arrest and differentiation, constantly evolving mutant sublines, genetic instability, and an ever-changing metabolic and vascular environment.

Results of a randomized trial comparing intra-arterial cisplatin and intravenous PCNU for the treatment of primary brain tumors in adults: Brain Tumor Cooperative Group trial 8420A

PURPOSE

To test the efficacy of intra-arterial (IA) cisplatin versus intravenous (IV) PCNU for treating primary brain tumors, in a randomized trial (Brain Tumor Cooperative Group [BTCG] Trial 8420A).

METHODS

311 adult patients (ages 19-79 years; median 45) with supratentorial tumors (confirmed histologically) were randomized by nine participating institutions. Patients were required to have completed radiotherapy (4500-6020 cGy to the tumor bed) before randomization. Patients were stratified as either nonprogressive (clinically and radiologically stable) or progressive. Results were analyzed for the 311 patients in the randomized population (RP), and for the 281 patients in the Valid Study Group (VSG) meeting protocol eligibility requirements. 56% of patients in the VSG had glioblastoma multiforme, 33% had other malignant glioma, and 11% had low-grade glioma. 64% were stratified as progressive. 12% had received prior chemotherapy.

RESULTS

The group randomized to PCNU had the longer survival (p = 0.06 for the RP, p = 0.07 for the VSG). In the VSG, median survival was 10 months for the cisplatin group, 13 months for the PCNU group. The difference between treatment groups was significant (p < or = 0.02) when adjusted for important prognostic factors. PCNU lead to greater hematotoxicity; cisplatin lead to greater renal toxicity and some ototoxicity. Some cisplatin patients experienced complications associated with IA administration, including six cases of encephalopathy.

CONCLUSION

The trial showed a survival advantage to the group randomized to PCNU, although the difference was modest. Coupled with previous BTCG results, these trails suggest that PCNU is an active drug for brain tumors.

The risk and efficacy of anticoagulant therapy in the treatment of thromboembolic complications in patients with primary malignant brain tumors

Twenty-three patients with malignant glial neoplasms were treated with anticoagulant therapy for thromboembolic complications. Fifteen patients had deep vein thrombosis alone, and 8 patients had both deep vein thrombosis and pulmonary embolism. Serum prothrombin times were maintained at 1.25 times control for an average of 5.8 months per patient, for a total patient exposure to warfarin therapy of 132 patient-months (11 patient-years). Only 1 patient suffered a recurrent pulmonary embolism, and this occurred during an episode of gastrointestinal bleeding, when anticoagulant therapy had to be discontinued prematurely. All patients were followed with serial computed tomographic or magnetic resonance imaging scans, and no patient showed radiographic evidence of intratumoral hemorrhage either during or after warfarin therapy. One patient, who died from a large recurrent glioblastoma, was found at autopsy to have scattered foci of intratumoral hemorrhage. This series, together with a review of the available literature, suggests that oral anticoagulant therapy is both a safe and effective means of treating thromboembolic complications in patients with residual malignant glial tumors.

Materials for selective tissue heating in a radiofrequency electromagnetic field for the combined chemothermal treatment of brain tumors

A technique of creating localized heating by implanting metallic materials in the brain and inserting the head into a radiofrequency electromagnetic field is described. The heating properties of various materials for implantation were studied, and the two best materials were carbon steel rods and Hysterloy (1000 and 655 cal/g-min, respectively). Heating of these materials was done primarily by eddy current since their heating rates were significantly affected by their shapes and orientation in the field, rods oriented parallel to the field producing the most heat. There is evidence that warmer cells have a greater uptake of chemotherapeutic agents. This suggests a combined therapeutic approach employing localized brain heating in conjunction with systemic or intrathecal chemotherapy. In this way, large doses of chemotherapeutic drugs might be concentrated in a warmed brain tumor while toxicity is prevented by keeping the rest of the brain and body hypothermic.

A comparison of the relative chemosensitivity of human gliomas to tamoxifen and n-desmethyltamoxifen in vitro

Tamoxifen has been shown to inhibit the proliferation of human gliomas in vitro. This inhibition is independent of tamoxifen's known anti-estrogenic properties. Tamoxifen is an inhibitor of protein kinase C (PKC), a calcium- and phospholipid-dependent serine kinase which plays a critical role in the proliferation of certain cell lines. Gliomas overexpress PCK, and their growth rate is coupled to the level of this key enzyme. As such, the effect of tamoxifen may be mediated by its inhibitory effect on PKC. To further investigate this possibility, we compared the chemosensitivity of cultured glioma lines to both tamoxifen and N-desmethyltamoxifen (DMT). DMT is the major metabolite of tamoxifen in humans and is a ten-fold more potent inhibitor of PKC. Seven lines were tested using the standard MTT assay, which quantitates metabolically active cells colorimetrically using a tetrazolium dye. Four of the seven lines were also tested using a tritiated thymidine uptake assay. In the MTT assay, all seven lines showed significantly greater sensitivity to DMT, while three of the four lines tested in the thymidine uptake assay were more sensitive to DMT. Correlation between the two assays was good. The dose of tamoxifen required to produce a 50% inhibition of optical absorbance or thymidine uptake (ID50) was typically five- to ten-fold greater than the ID50 for DMT, approximating the relative strength of the two compounds as PKC inhibitors. In addition to providing some support for the ypothesis that triphenylethylenes inhibit gliomas via PKC inhibition, these findings have clinical significance.(ABSTRACT TRUNCATED AT 250 WORDS)