Supportive care management of brain metastases: what is known and what we need to know. Conference proceedings of the National Cancer Institute of Canada (NCIC) Workshop on Symptom Control in Radiation Oncology.

OBJECTIVES: To review the results of published randomised controlled trials in the treatment of brain metastases and, from the knowledge gained from these trials, to identify potential study questions. MATERIALS AND METHODS: The literature was searched for randomised controlled trials that dealt with the management of brain metastases. Potential research questions were identified on the basis of the results of the literature review. RESULTS: A number of research questions were identified. In the context of the NCIC Symptom Control Group, a trial of supportive care alone vs supportive care and whole-brain radiotherapy (WBRT) in a subset of patients with the diagnosis of brain metastases was deemed to be of highest priority. We discussed a number of issues relating to the feasibility of such a trial. CONCLUSIONS: The optimal management of brain metastases remains elusive. Despite the results of numerous randomised controlled trials, many questions remain unanswered. The magnitude of benefit using WBRT above supportive care alone is uncertain. A trial of supportive care alone vs supportive care and WBRT may be successful once target population, feasibility and methodological issues are thoroughly solved.

A prospective study of short course radiotherapy in elderly patients with malignant glioma.

Elderly patients with malignant glioma have a poor prognosis and the benefit of standard radical radiotherapy is equivocal. Twenty-two percent of the adult referral base with malignant glioma at our centre is of age 70 years or greater. A phase II study was undertaken to determine if a shorter course of therapy yields a comparable median survival to radical radiotherapy and thus constitutes an appropriate investigational palliative regimen. 25 patients were accrued between 1988-1995, all of whom had histologically proven malignant glioma, 23 glioblastoma multiforme and 2 anaplastic astrocytoma. The median age was 73 (range 70-78) and median Karnofsky Performance Status (KPS) was 70.40% had a stereotactic biopsy only for diagnosis. Radiotherapy was delivered to limited fields to a dose of 37.5 Gy in 15 daily fractions over 3 weeks. An intention-to-treat analysis was undertaken with survival determined from date of initial consultation. The median survival of the whole group was 8.0 months (95% CI 4.8-9.6). Patients with good performance status (KPS > 70) had a median survival of 10.4 months (95% CI 9.6-14.7). 37.5 Gy in 15 daily fractions appears to yield comparable median survival to that of other series of radical radiotherapy. A phase III study of this regimen is recommended in investigating optimal palliation of elderly malignant glioma patients.

Radiotherapy for palliation of symptoms in incurable cancer.

Approximately one half of prescribed radiotherapy is given for palliation of symptoms due to incurable cancer. Distressing symptoms including pain, bleeding, and obstruction can often be relieved with minimal toxic effects. Painful osseous metastasis is common in oncologic practice. Ninety percent of patients with symptomatic bone metastases obtain some pain relief with a lowdose, brief course of palliative radiotherapy. One half of the responding patients may experience complete pain relief. A single dose of 800 cGy in the setting of painful bone metastasis may provide pain control comparable to more protracted treatment at a higher dose of radiation. Patients with lytic disease in weight-bearing bones, particularly in the presence of cortical destruction, should be considered for prophylactic surgical stabilization of their condition. Routinely a brief, fractionated course of radiotherapy is given postoperatively. Pain due to multiple bone metastases uncontrolled by analgesics can be managed with single doses of halfbody irradiation. Doses of 600 cGy delivered to the upper half-body (above the umbilicus) and 800 cGy to the lower half-body (from the umbilicus to the middle of the femur) will provide some pain relief in 73% of patients. Half-body techniques have been investigated as prophylactic treatment, as a complement to local-field irradiation, and as fractionated rather than singledose therapy. Although intravenous administration of strontium 89 has been associated with myelosuppression, this treatment has been shown (a) to relieve pain due to bone metastasis and (b) to delay development of new painful sites. Recent data from phase III trials demonstrated that bisphosphonates have a role in reducing skeletal morbidity due to bone metastasis. Bone pain was reduced, and the incidence of pathologic fracture and the need for future radiotherapy was decreased. Radiotherapy relieves clinical symptoms in 70% to 90% of patients with brain metastases. Brief treatment schedules (e.g., 2000 cGy in five fractions over 1 week) are as effective as more prolonged therapy. Patients with solitary brain metastasis and no extracranial disease or controlled extracranial disease should be considered for surgical resection, because phase III data indicate enhanced survival with such an approach. Whole-brain radiotherapy is routinely administered postoperatively. A phase III study is examining the impact of accelerated fractionated doses of radiotherapy (two treatments per day) on survival of patients with brain metastases. Stereotaxic radiosurgical treatment is becoming increasingly available and permits delivery of radiation to metastatic intracranial tumor with minimal exposure of normal surrounding brain This treatment is most commonly used at the time of a solitary recurrence of disease in patients who previously received whole-brain radiotherapy. A role for this modality in newly diagnosed brain metastases remains to be defined. Chest symptoms are common in patients with locally advanced lung cancer and are effectively palliated with one 1000 cGy or two 850 cGy one fraction doses of radiation to the thoracic inlet and mediastinum. Chest pain and hemoptysis are more effectively palliated than cough and dyspnea. In patients with stage III cancer there is no compelling evidence that radiotherapy confers a survival advantage, and it may be reasonable to administer thoracic radiotherapy only when the patient has significant symptoms and the goal is to achieve control of these symptoms. Approximately 75% of the cases of superior vena cava syndrome are due to lung cancer, and small-cell lung cancer is the most common histologic type. A histologic diagnosis should be obtained before treatment is started, because detection of lymphoma or small-cell carcinoma would necessitate systemic therapy. Eighty percent of the patients with vena cava syndrome due to malignant disease achieve symptom relief with a brief, fractionated, palliative course of rad

Rat brain regional preproenkephalin A messenger RNA levels are altered in genetic hypertension.

Considerable neuroanatomical and pharmacological evidence suggests that preproenkephalin A-derived peptides, particularly methionine-enkephalin, are involved in regulation of the cardiovascular system in both physiological and pathological states. In this study, we used a rat preproenkephalin A complementary DNA to determine whether proenkephalin A-derived peptides participate in the pathogenesis of hypertension as reflected by brain regional messenger RNA levels. Complementary DNA clones of the rat preproenkephalin A mRNA and rat small myelin basic protein mRNA were hybridized to total RNA extracted from hypothalamus, pons-medulla, thoracic cord, midbrain, and cerebellum of 3 1/2-week-old and 12-week-old Wistar-Kyoto (WKY) and spontaneously hypertensive (SHR) rats. In 3 1/2-week and 12-week animals there were no differences in the levels of myelin basic protein messenger RNA between the two groups in any brain region. At 3 1/2 weeks, preproenkephalin A mRNA levels did not differ between normotensive and hypertensive strains. In contrast, at 12 weeks preproenkephalin A mRNA levels were increased in hypothalamus, midbrain, thoracic cord, and cerebellum of SHR relative to WKY. Preproenkephalin A mRNA was significantly reduced in the pons-medulla of SHR relative to WKY. Our findings provide evidence that alterations in brain regional preproenkephalin A mRNA levels are associated with the development of spontaneous hypertension in the rat.