Martin Schabet

Epidemiology of primary CNS lymphoma.

In the beginning of the nineties the National Cancer Institute Surveillance, Epidemiology, and End Results Program calculated the incidence of primary central nervous system non-Hodgkins lymphoma (PCNSL) as 1:100 000. The incidence of PCNSL has been increasing since the seventies in immunocompetent patients. The main increase, however, is taking place since the mid-eighties and is due to the increase of immunodeficieny and immunosuppression. The risk is 2–6% in AIDS patients according to clinical data and will probably further increase with the length of survival in these patients. Transplant patients carry a risk of 1–5% to develop a PCNSL. The risk is 1–2% for renal, and 2–7% for cardiac, lung or liver transplant recipients. Patients with congenital immune deficiency have a risk of 4%. PCNSL may also present as a secondary malignancy.

German Cancer Society Neuro‐Oncology Working Group NOA‐03 multicenter trial of single‐agent high‐dose methotrexate for primary central nervous system lymphoma

The prospective multicenter NOA‐03 trial, conducted by the Neuro‐Oncology Working Group (NOA) of the German Cancer Society, was initiated to define the feasibility and efficacy of single‐agent high‐dose methotrexate therapy without concomitant radiotherapy in immunocompetent patients with primary central nervous system lymphoma. Thirty‐seven patients (median age, 60 years) received 179 biweekly courses of 8g/m2 methotrexate. Response was assessed after 3 and 6 courses. We had planned to enter 105 patients into the trial. Since fewer than the projected 18 of 37 patients achieved a complete response after an intermediate analysis, the trial was closed. In intention‐to‐treat analysis, 11 of 37 patients (29.7%) achieved complete response, whereas 14 of 37 patients (37.8%) were found to have progressive disease. The median relapse‐free survival among complete response patients was 13.7 months. Multivariate logistic regression analysis revealed that corticosteroid application during the first methotrexate course was associated with complete response. The regimen was well tolerated, but, unlike previously reported results, the activity of high‐dose methotrexate was only moderate.

Changes of Cerebrovascular CO2 Reactivity During Normal Aging

BACKGROUND AND PURPOSE During the past decade, transcranial Doppler sonography has widely been used to assess blood flow velocities in the basal intracranial arteries and cerebrovascular reactivity (CR) to various stimuli. Although numerous studies have shown a decline of cerebral blood flow velocity with age, the age dependency of CR, including cerebrovascular CO2 reactivity, however, is controversial. Recently, we have reported a significant sex-related difference in CR, stressing the need to study the relation between normal aging and CR in both sexes separately. METHODS By means of transcranial Doppler sonography, CR was determined in 100 healthy, nonsmoking volunteers (age 20 to 70 years, 10 men and 10 women per decade). RESULTS In men, no change of CR with increasing age could be observed (P=0.98). In contrast, CR in women declined significantly, with a step decrease from the 4th to the 5th decades (F=4.413; P<0.01) and was significantly higher in the 3rd and 4th compared with the 5th, 6th, and 7th decades (P<0.05). Information on hormone replacement therapy (HRT) in women of the 6th and 7th decades was obtained retrospectively. HRT was associated with enhanced CR (HRT, n = 7 versus non-HRT, n = 13; P<0.001), with values similar to those found in premenopausal women. CONCLUSIONS There are no changes of CR during normal aging in men, whereas CR declines significantly from the 4th to the 5th decades in women. HRT in postmenopausal women appears to enhance CR.

Malignant glioma: patterns of failure following individually tailored limited volume irradiation

Treatment outcome was analyzed for 66 patients with malignant glioma treated with individually CT-planned multifield irradiation techniques. Total doses of 60 Gy were given, with the planning target volume (PTV) including 2 cm beyond the tumour indicated by preoperative CT examination. Median survival was 14 months, and 86% of recurrences occurred in the treated volume. Our results suggest that the used PTV and radiation technique should be appropriate in radiotherapy of malignant glioma.

Manifestation of Hashimoto's encephalopathy years before onset of thyroid disease.

Patients with Hashimoto’s encephalopathy (HE), a steroid-responsive disorder, associated with Hashimoto’s disease and high levels of thyroid-related autoantibodies usually present with a subacute onset of confusion, focal or generalized seizures. Frequent EEG abnormalities include generalized, rhythmic bifrontal or temporal slowing. Elevated protein levels or an intrathecal IgG synthesis may be present in cerebrospinal fluid (CSF). A 39-year-old woman underwent a relapsing course of myocloni and generalized seizures. Initially, thyroid function, thyroid-related autoantibody screening and cerebral MRI were unrevealing. CSF showed oligoclonal bands. Short-term treatment with high doses of prednisolone resolved the myocloni. During the 5th episode of myocloni, signs of hyperthyroidism and elevation of thyroid microsomal antibody titer developed. Hashimoto’s thyroiditis and HE were diagnosed. After subtotal thyroidectomy the patient remained asymptomatic.

Primary Central Nervous System Lymphoma: From Clinical Presentation to Diagnosis

Immunocompetent patients with primary central nervous system lymphoma (PCNSL) present with a median age of 55 years, immunosuppressed patients with a median age of 40 years. They show a broad range of signs and symptoms. Symptoms of increased intracranial pressure and personality change are most frequent, followed in frequency by ataxia and hemiparesis. The median time from onset of symptoms to diagnosis is 3–5 months in immunocompetent patients and 2 months in immunodeficient patients. The time to diagnosis can be considerably longer in patients with slowly developing personality change or fluctuating symptoms due to spontaneous or steroid-induced remission of so-called sentinel lesions. Native CT scans show iso- or hyperdense lesions with homogenous contrast enhancement. T1-weighted MRI scans show hypointense and T2-weighted scans hyperintense lesions. The definitive diagnosis of PCNSL requires biopsy. In some cases, however, the definitive diagnosis may exclusively be made by the demonstration of malignant B-lymphocytes in the cerebrospinal fluid.

BCL-2 family protein expression in human malignant glioma: a clinical-pathological correlative study

Malignant gliomas are rather refractory to current therapeutic approaches including surgery, radiotherapy, chemotherapy and immunotherapy. Acquired alterations in the pathways required for apoptotic cell death are thought to be responsible to the failure of glioma to respond to therapy. Here we have examined the expression of several proteins involved in the susceptibility to apoptosis in 20 human gliomas, including the BCL-2 family proteins BCL-2, BCL-X, BAX and MCL-1, as well as p53 and RB. Most gliomas expressed several BCL-2 family proteins. There was good correlation between expression of the functional antagonists, BCL-2/BCL-X and BAX, suggesting that changes in the BCL-2+BCL-X/BAX ratio are not responsible for the differential response of glioma patients to chemotherapy. The immunochemistry data were also analysed in regard to response to therapy and clinical outcome. All patients had cytoreductive surgery and received radiotherapy and nitrosourea-based adjuvant chemotherapy. There was no prominent association of outcome with the expression patterns of p53, RB, BCL-2, BCL-X or BAX. We find, however, that expression of the MCL-1 protein is associated with early tumour recurrence and shorter survival in this group of glioma patients. This preliminary observation will have to be confirmed in a larger independent sample of glioma patients.

Adult medulloblastoma: prognostic factors and response to therapy at diagnosis and at relapse.

AbstractAdult medulloblastoma is a rare tumor with few retrospective studies published so far. The role of adjuvant chemotherapy or chemotherapy at relapse is unclear. This study reports therapy and outcome in all adult (≥ 16 years old) medulloblastoma (n = 34) and supratentorial primitive neuroectodermal tumor (PNET) patients (n = 2) treated in 2 neuro–oncological centers between 1976 and 2002. The median age was 24.5 years (range 16–76). After resection, 16 patients were treated with craniospinal radiotherapy alone, 20 patients also received adjuvant chemotherapy (8 vincristine, CCNU, cisplatin; 7 methotrexate alone or methotrexate/vincristine–based polychemotherapy; 5 other protocols). Median survival in the whole cohort was 126 months (2+ – 200+ months). Five–year and 10–year survival rates were 79 % and 56%. Adjuvant chemotherapy was associated with a non–significant trend to prolonged survival (relative risk (RR) 1.89; p = 0.068). The median progression–free survival (PFS) after primary therapy was 83 months. At relapse, 10 of 12 evaluable patients achieved a complete response upon second–line therapy. The median survival times from first (n = 17) and second relapse (n = 9) were 21 months (0–67+ months; 5/17 without second relapse) and 20 months (1–29 months). Cox regression analysis revealed the infiltration of the floor of the 4th ventricle at diagnosis as the only therapy–independent prognostic factor (RR 0.48; p = 0.03). In conclusion, adjuvant chemotherapy may prolong survival in adult medulloblastoma patients. Moreover, second–line therapy may be beneficial for these patients. As in pediatric medulloblastoma patients, primary infiltration of the floor of the 4th ventricle indicates a poor prognosis.

Hypericin-induced apoptosis of human malignant glioma cells is light-dependent, independent of bcl-2 expression, and does not require wild-type p53

Hypericin and tamoxifen are experimental agents for the adjuvant chemotherapy of malignant glioma. We report that hypericin and tamoxifen induce apoptosis of 7 human malignant glioma cell lines in a concentration- and time-dependent manner. Illumination is essential for the cytotoxicity of hypericin but not tamoxifen. Apoptosis is unaffected by inhibitors of RNA and protein synthesis or free radical scavengers, does not require wild-type p53 activity, and occurs in glioma cells expressing high levels of bcl-2. There is no correlation between hypericin and tamoxifen-induced cytotoxicity and inhibition of protein kinase C (PKC). Ectopic expression of a murine bcl-2 transgene provides modest protection from tamoxifen but does not affect hypericin toxicity. Hypericin and tamoxifen do not modulate glioma cell killing induced by tumor necrosis factor-alpha (TNF-alpha) or CD95 ligand. Both drugs augment the acute cytotoxicity of various cancer chemotherapy drugs but fail to shift their EC50 values in modified colony formation assays. These data do not provide further supportive evidence how to enhance the limited efficacy of tamoxifen treatment for human malignant glioma. However, hypericin is a promising agent for the treatment of malignant glioma if local photodynamic activation of hypericin in the glioma tissue can be achieved.

A role for preirradiation PCV chemotherapy for oligodendroglial brain tumors

Abstract Oligodendroglial tumors have been identified as a subgroup of glial neoplasms with a distinctly better response to chemotherapy and overall survival than purely astrocytic gliomas. Here we report our experience with adjuvant postirradiation and preirradiation chemotherapy using procarbazine, lomustine, and vincristine (PCV) in 27 patients with WHO grade II or III oligodendroglioma or oligoastrocytoma. The efficacy of chemotherapy was assessed according to the Macdonald response criteria (complete response, CR; partial response, PR; stable disease, SD; progressive disease, PD) and progression-free survival intervals by computed tomography or magnetic resonance imaging. First, we confirm that PCV salvage therapy for patients progressing after radiotherapy is highly effective (n = 11, 1 CR, 5 PR, 5 SD; median progression-free survival has not yet been reached, but is longer than 18 months). Second, 3 patients who received radiotherapy plus PCV as first-line therapy achieved CR and 2 achieved SD, and all 5 are progression-free with a median follow-up of 12 months. Third, given these encouraging results, 11 patients received postoperative preirradiation PCV chemotherapy and were given radiotherapy only upon progression. Preirradiation PCV chemotherapy was also effective (2 CR, 3 PR, 6 SD; median progression-free survival has not been yet reached, but is longer than 14 months). Patients with anaplastic oligoastrocytomas were as likely to respond to PCV chemotherapy, as were patients with anaplastic oligodendroglioma. Three patients who had previously responded to PCV were successfully treated with a second course of PCV upon recurrence. PCV chemotherapy was also effective in patients with leptomeningeal spread of oligodendrogliomas. A randomized prospective trial is required to compare the effectiveness and neurotoxicity of first-line PCV chemotherapy followed by radiotherapy to the traditional reverse sequence.