Faculty Bibliography

The incidence of childhood brain tumors appears to be on the rise caused in part by improvements in neuroimaging and its increased availability. Current protocols for treatment of childhood brain tumors are utilizing chemotherapy more extensively in addition to and in lieu of radiotherapy to improve survival for tumors such as medulloblastoma and high grade astrocytoma, and to lessen treatment related morbidity in infants with malignant brain tumors and in older children with standard risk medulloblastomas and germ cell tumors. The increasing understanding of the molecular events that lead to oncogenesis will help unravel the causes and improve therapy for a group of illnesses that cause significant neurologic morbidity and mortality

The 5 year survival for patients with malignant intracranial non-germinoma germ cell tumors (NGGCT) which include endodermal sinus tumors, embryonal carcinomas, choriocarcinomas and immature teratomas is less than 25% following a small resection and radiotherapy. In an effort to improve the survival of these patients, an approach using an attempt at radical resection where feasible followed by multi-modality 'sandwich' therapy (chemotherapy-radiation-chemotherapy) was used to treat 18 newly diagnosed patients between 1986 and 1994 in a multi-institution study. Fourteen patients had histologically proven NGGCT and four were presumed NGGCT because of markedly elevated concentrations of serum and/or CSF alpha fetoprotoin (AFP) and/or beta human chorionic gonadatrophin (b-HCG). The primary tumor was confined to the pineal region in 12 patients, the suprasellar region in five, and a cerebral hemisphere in one. None of the patients had central nervous system metastases at diagnosis by MRI imaging of the spine and CSF cytology. Radical surgical resection was performed initially in 11 patients (gross total -6, subtotal -5): four had a biopsy and three had no surgery. All patients then received 3 or 4 cycles of neoadjuvant chemotherapy with cisplatin (100 mg/m2/cycle) and VP-16 (500 mg/m2/cycle). Of the 12 patients with evaluable disease there were 9 responses to the neoadjuvant chemotherapy (5 CR, 4 PR); 2 patients had stable disease and I progressed during chemotherapy. Six patients with no evaluable disease after a gross total resection had a continuous complete response. Seventeen patients received radiation therapy (involved field -11, involved field + craniospinal -4, involved field + whole brain -2). Twelve patients received 4 cycles post-radiation chemotherapy with vinblastine (6.5 mg/m2/cycle). bleomycin (15 U/m2/cycle), VP-16 (300 mg/m2/cycle, carboplatin (450 mg/m2/cycle). A total of four patients have died (3-progressive/recurrent disease, 1-metabolic). Four year actuarial event-free and total survival rates are 67% and 74%. This multi-modality adjuvant therapy approach appears to dramatically improve the outcome of malignant intracranial NGGCT

In response to injury, vascular smooth muscle cells (VSMC) are thought to migrate toward the area of damage, where they participate in the reparative process. We have recently identified and isolated two distinct cell types (VSMC and type 2 cells) from the tunica media of canine carotid artery and saphenous vein. The purpose of these experiments was to determine whether both cell types were able to migrate in response to a variety of chemoattractants. A multiwell Boyden chamber and a wound migration assay were used to assess the migratory ability of these cells in vitro. The results indicated that VSMC did not exhibit directed migration in response to either 10% fetal bovine serum or platelet-derived growth factor (PDGF)-AB. In contrast, type 2 cells migrated to serum, PDGF-AB, and PDGF-BB but not to PDGF-AA, endothelin (ET)-1, or ET-3. No difference in migratory ability was detected between type 2 cells isolated from carotid arteries or saphenous veins. It is concluded that the migratory ability of cells within the tunica media of vessels from adult animals are not equal, suggesting that only selected cells may participate in vascular wall repair.

Evidence for an H+-K+-adenosinetriphosphatase (HKA) in vascular smooth muscle cells has recently been demonstrated in the rat aorta and a rat smooth muscle cell line (A(7)r(5)) by functional studies. Our laboratory has used reverse transcriptase (RT)-polymerase chain reaction (PCR) and Northern hybridization techniques to define the type of HKA present in canine whole carotid artery and confluent carotid artery cells. PCR primers to detect an HKA message of unknown isoform were designed on the basis of homology to known sequences of gastric, colonic, and toad bladder HKA isoforms and dissimilarity to the Na+-K+-adenosinetriphosphatase isoforms. A PCR product of predicted size was generated from cDNAs of both confluent cells and whole vessel carotid artery that possess 91% nucleotide sequence identity to the canine gastric HKA. Northern hybridization with the PCR product as a probe revealed hybridization to whole vessel carotid artery, cultured confluent carotid artery cell, kidney, and stomach canine total RNA at the known message size for the gastric HKA isoform. These data suggest that vascular smooth muscle cells express an HKA mRNA that may be identical to the gastric isoform.

We assessed the effect of cranial irradiation on hypothalamic-pituitary (HP)-adrenal function in 17 patients (12 females, 5 males) treated with cranial/ craniospinal irradiation for acute leukemia (2 patients) or tumors distant from the hypothalamus and pituitary (8 medulloblastoma, 3 astrocytoma, 3 rhabdomyosarcoma, 1 ependymoma). Estimated doses of radiation (RT) to the HP region ranged from 18 to 72 Gy. Thirteen of seventeen patients were also treated with chemotherapy. Patients were a median of 3.75 years of age (1.5-19 years) at diagnosis and were studied at a median of 5 years (0.1-20 years) after RT. Patients received corticotropin-releasing factor (oCRF, 1 microgram/kg i.v.), and sampling for cortisol and ACTH levels was performed at -15, 0, 15, 30, 60, 90 and 120 min. The-5- and 0-min levels were combined for a standardized baseline value (Base). Cortisol levels at 0, Base, 30 and 120 min, as well as the peak cortisol response, were significantly lower in the patients. Twelve of seventeen patients' peak cortisol levels fell below the normal range. The patients' mean integrated values for cortisol (area under the curve) were not, however, different from controls. The ACTH responses to oCRF did not differ between patients and controls. No relationship was observed between ACTH or cortisol responses and the time elapsed from treatment or dose of HP RT. Further, in 10 of 12 patients, 0-min dehydroepiandrosterone sulfate levels were lower than the expected normal mean levels for age, sex and pubertal status, and in 4 of these 10 patients the values were below the normal range. These data suggest that some patients treated with HP RT may be at risk for adrenal insufficiency

PURPOSE: This single-institution Phase III study conducted from 1989 to 1995 evaluates the feasibility of a multimodality protocol combining hyperfractionated craniospinal radiotherapy (HFRT) followed by adjuvant chemotherapy in 23 patients with newly diagnosed primitive neuroectodermal tumors (PNET) arising in the central nervous system. METHODS AND MATERIALS: All 23 patients had a histologically confirmed PNET and were over 3 years of age at diagnosis. The eligibility criteria for PNET patients with cerebellar primaries (medulloblastoma) included either a high T stage (T3b or 4) or high M stage (M1-3). All patients with noncerebellar primaries were eligible regardless of T or M stage. The median age of the 23 patients was 9 years (mean 3-25); 11 were female. The primary tumor arose in the cerebellum in 19. Of these medulloblastoma patients, 15 had high T stages (T3b or T4) with large locally invasive tumors and no evidence of metastases (M0), constituting Group 1. Thirteen (86%) of these patients had gross total resections. Four other medulloblastoma patients had both high T and high M stages, constituting Group 2. Group 3 consisted of four other patients with exocerebellar primaries (two brain, one brain stem, and one cauda equina), three of whom were M3. Hyperfractionated radiotherapy was administered within 4 weeks of surgery. Twice-daily 1-Gy fractions were administered separated by 4-6 h. The total dose to the primary intracranial tumor and other areas of measurable intracranial disease was 72 Gy. The prophylactic craniospinal axis dose was 36 Gy, and boosts of 44-56 Gy were administered to metastatic spinal deposits. Following radiotherapy, monthly courses of multiagent chemotherapy were administered sequentially (cyclophosphamide-vincristine followed by cisplatin-etoposide followed by carboplatin-vincristine) for a total of 9 months. RESULTS: All patients completed radiotherapy as planned. Only three patients lost >10% of their body weight. One patient had clinically apparent radiation-induced esophagitis. The mean white blood count (WBC) nadir was 2.5/dl, and hematologic recovery occurred in all within 4 weeks of completing HFRT without the need of granulocyte-colony-stimulating factor. Two patients refused adjuvant chemotherapy, 3 patients experienced tumor progression during chemotherapy, and 2 of 18 remaining patients could not tolerate the full 9 months owing to hematologic toxicity. Of the 15 patients (93%) in Group 1, 14 remain in continuous remission for a median of 78 months, and none have died. Two of four patients in Group 2 are in continuous remission at 67 and 35 months, and two died at 18 and 30 months. One of the two patients in Group 2 who died refused adjuvant chemotherapy and developed tumor progression in the bone marrow. None of the three patients in Group 3 with evaluable disease (M3) had a complete response to therapy, and eventually all four died of progressive or recurrent disease. CONCLUSION: This multimodality protocol is feasible in the short term, and long-term monitoring of neurocognitive and neuroendocrine effects are in progress. Excellent long-term disease control has been achieved for medulloblastoma patients with high T stages who were M0 at diagnosis (Group 1), the majority of whom had gross total resections. This group has a progression-free survival of 95% after a median period of follow-up of 6.5 years. Alternative treatment strategies must be developed for patients with high M stages, as five of seven patients died of progressive or recurrent disease

Over a 13-year period extending from 1980 to 1993, 27 children less than 3 years of age underwent operation for removal of an intramedullary spinal cord tumor (IMSCT). The majority (18 of 27) of children had undergone surgery before being referred to New York University (NYU) Medical Center. The most common reasons for radiological investigation were pain (42%), motor regression (36%), gait abnormalities (27%), torticollis (27%), and progressive kyphoscoliosis (24%). Forty procedures were performed in 27 children. Nine children underwent two operations and two children underwent three procedures. A gross-total resection was achieved in 72% of the procedures. There was no surgical mortality. A comparison of the preoperative and 3-month postoperative functional grades for the first NYU procedure (NYU-1) yielded the following findings: 20 patients' conditions remained the same, five patients improved, and two patients deteriorated. The functional outcomes of a second operation (NYU-2) were similar. The majority of the children (24 of 27, 89%) had histologically determined low-grade lesions. There were 12 patients with low-grade astrocytomas (Grades I-III), eight with gangliogliomas, two with ganglioglioneurocytomas, one with a glioneurofibroma, and one child with a mixed astro/oligodendroglioma. Two children had anaplastic astrocytomas (Grades II-III) and one child had a glioblastoma multiforme. In a median follow-up review of 76 months, two patients died and two patients were lost to follow up. The 3- and 5-year progression-free survival (PFS) rates were 81.7% (standard error of the mean (SEM) 0.083) and 76.2% (SEM 0.094), respectively. Eight of 24 patients suffered a recurrence within a mean time of 45.4 +/- 28.9 months. All were treated with surgery (NYU-2). Lesions recurred in three of 12 children with low-grade astrocytomas, two of eight children with gangliogliomas, one child with an anaplastic astrocytoma, one child with a ganglioglioneurocytoma, and one child with a glioblastoma multiforme. At follow-up review, most of these children were doing well. Sixteen are in functional Grades I or II and 18 children attend a normal school system. The authors conclude that surgery for the removal of IMSCTs in children less than 3 years of age can be performed radically and safely. The postoperative functional performance is determined by the degree of the preoperative deficit. It is, therefore, of utmost importance to diagnose and treat these children as early as possible. Spinal cord tumors should be recognized as potentially excisable lesions on their initial presentation and when they recur. The optimum treatment for malignant lesions is still to be determined