Preclinical validation of a novel therapeutic strategy for choroid plexus carcinoma

Choroid plexus carcinoma (CPC) is a rare infantile brain tumor with an aggressive clinical course that often leaves children with debilitating side effects due to aggressive and toxic chemotherapies. Development of novel therapeutical strategies for this disease have been extremely limited owing to the rarity of the disease and the paucity of biologically relevant substrates. We conducted the first high-throughput screen (HTS) on a human patient-derived CPC cell line (Children Cancer Hospital Egypt, CCHE-45) and identified 427 top hits highlighting key molecular targets in CPC. Furthermore, a combination screen with a wide variety of targets revealed multiple synergistic combinations that may pave the way for novel therapeutical strategies against CPC. Based on in vitro efficiency, central nervous system (CNS) penetrance ability and feasible translational potential, two combinations using a DNA alkylating or topoisomerase inhibitors in combination with an ataxia telangiectasia mutated and rad3 (ATR) inhibitor (topotecan/elimusertib and melphalan/elimusertib respectively) were validated in vitro and in vivo. Pharmacokinetic assays established increased brain penetrance with intra-arterial (IA) delivery over intra-venous (IV) delivery and demonstrated a higher CNS penetrance for the combination melphalan/elimusertib. The mechanisms of synergistic activity for melphalan/elimusertib were assessed through transcriptome analyses and showed dysregulation of key oncogenic pathways (e.g. MYC, mammalian target of rapamycin mTOR, p53) and activation of critical biological processes (e.g. DNA repair, apoptosis, hypoxia, interferon gamma). Importantly, IA administration of melphalan combined with elimusertib led to a significant increase in survival in a CPC genetic mouse model. In conclusion, this study is, to the best of our knowledge, the first that identifies multiple promising combinatorial therapeutics for CPC and emphasizes the potential of IA delivery for the treatment of CPC.

Myc and Loss of p53 Cooperate to Drive Formation of Choroid Plexus Carcinoma

Choroid plexus carcinoma (CPC) is a rare brain tumor that occurs most commonly in very young children and has a dismal prognosis despite intensive therapy. Improved outcomes for patients with CPC depend on a deeper understanding of the mechanisms underlying the disease. Here we developed transgenic models of CPCs by activating the Myc oncogene and deleting the Trp53 tumor suppressor gene in murine neural stem cells or progenitors. Murine CPC resembled their human counterparts at a histologic level, and like the hypodiploid subset of human CPC, exhibited multiple whole-chromosome losses, particularly of chromosomes 8, 12, and 19. Analysis of murine and human CPC gene expression profiles and copy number changes revealed altered expression of genes involved in cell cycle, DNA damage response, and cilium function. High-throughput drug screening identified small molecule inhibitors that decreased the viability of CPC. These models will be valuable tools for understanding the biology of choroid plexus tumors and for testing novel approaches to therapy. SIGNIFICANCE: This study describes new mouse models of choroid plexus carcinoma and uses them to investigate the biology and therapeutic responsiveness of this highly malignant pediatric brain tumor.

Clinical outcome of adult choroid plexus tumors: retrospective analysis of a single institute

BACKGROUND

Choroid plexus tumors are rare brain tumors with clinical features that vary according to the histological grade. We reviewed the treatment outcomes of 15 adult patients with choroid plexus tumors, focusing on surgical outcomes and current therapeutic strategies.

METHOD

Patient demographic and clinical characteristics, operative findings, adjuvant therapies, disease progression and survival rates were reviewed.

RESULTS

The median age at diagnosis was 33.7 ± 10 years (19-59 years) for patients with choroid plexus tumors. Postoperative chemotherapy was given to 26.7 % of patients, and 13.3 % of patients received radiotherapy. The Ki-67 labeling index and mitotic index increased at higher histological grades. All of the choroid plexus papilloma and atypical choroid plexus papilloma patients have survived. The overall survival rate of patients with choroid plexus carcinoma was 50 % in the first year, but none of the patients survived to the second year. Five patients underwent permanent cerebrospinal fluid diversion surgery because of hydrocephalus or subdural effusion.

CONCLUSIONS

Choroid plexus papilloma and atypical choroid plexus papilloma patients can be treated with complete surgical resection. Choroid plexus carcinoma has a poor prognosis, and aggressive multi-modal treatments are generally needed for treatment. Chemotherapy and radiotherapy are important adjuvant therapies for choroid plexus carcinoma. If hydrocephalus and/or subdural effusion occur, permanent cerebrospinal fluid (CSF) diversion should be added to the therapeutic strategy.

[Antiangiogenic treatment of pediatric CNS tumors in Hungary with the Kieran schedule]

In Hungary a new oral antiangiogenic treatment was introduced in cases of primary chemoresistant or recurrent pediatric CNS tumors, called Kieran schedule. The early results of this treatment were analyzed. From 2010 at Semmelweis University on individual decisions a daily combined per oral treatment was introduced in pediatric patients with recurrent or progressive CNS tumor (Kieran schedule: thalidomid, celecoxib, etoposid and cyclophosphamid). Efficacy of therapy was analyzed in terms of demographic data, histology, side effects and tolerability in a retrospective manner. From 2010 through 2013, twenty patients were treated with Kieran schedule (medulloblastoma: 3, ependymoma: 5, anaplastic astrocytoma: 2, GBM: 4, plexus choroideus carcinoma: 1, central primitive neuroectodermal tumor: 1, optic glioma: 2, brainstem tumor: 2). Median treatment time and median progression-free survival were 0.60 and 0.61 years, respectively. Based on the preliminary analysis of a limited cohort of patients, the therapy was efficient in those cases of medulloblastoma, ependymoma, high-grade and optic gliomas, where the expected survival time was more than 3 months at start of treatment. Side effects were slight myelosuppresion in terms of previous therapy, 16% transient ischemic attack (TIA)-like episodes. During therapy patients could live their everyday life. Kieran schedule was well-tolerable and efficient with good quality of life in certain cases of pediatric CNS tumors.

Pegylated-liposomal doxorubicin and oral topotecan in eight children with relapsed high-grade malignant brain tumors

BACKGROUND

The combination of topoisomerase I and II chemotherapeutic agents has shown promising preclinical synergistic effects in the treatment of high-grade malignant brain tumors such as high-grade gliomas and choroid plexus carcinomas. To confirm the effectiveness of this treatment combination and determine its possible toxicity, we conducted a retrospective review of the charts of children who received the therapy.

METHODS

Patients with relapsed malignant brain tumors who were given an individualized treatment of pegylated (PEG)-liposomal doxorubicin and topotecan were included in our study. PEG-liposomal doxorubicin was given intravenously at a dosage of 30-40 mg/m(2) over 4 h once every 4 weeks. Additionally, an intravenous formulation of topotecan was given orally twice daily and was increased on an individual basis from a starting dosage of 0.3 mg/m(2) per application to a total daily dosage of 0.6 mg/m(2).

RESULTS

Eight patients were included. The main toxicity (NCI-CTC) after three cycles of the combination therapy was grade IV hematotoxicity (n = 3); grade III hematotoxicity (n = 2), grade III stomatitis (n = 1), grade III infection (n = 2), grade III diarrhea (n = 1); and grade II dermatitis (n = 1). In four patients, stable disease was achieved for 9, 23, more than 24, and more than 48 weeks, respectively.

CONCLUSION

The schedule of PEG-liposomal doxorubicin with 30-40 mg/m(2) every 4 weeks in combination with oral topotecan resulted in tumor response, but the toxicity was high. An individualized increasing dose of PEG-liposomal doxorubicin 10-20 mg/m(2) every two weeks is now recommended.

Chemotherapy improves the survival of patients with choroid plexus carcinoma: a meta-analysis of individual cases with choroid plexus tumors

BACKGROUND

Choroid plexus carcinomas (CPC) are rare brain tumors with a dismal prognosis. Although the role of surgery has been well established, the question of whether chemotherapy improves the prognosis is still under discussion.

METHODS

We created a database of all cases of choroid plexus tumors (CPT) reported in the literature up to the year 2004 to determine prognostic factors and different therapeutic modalities. This database was validated by comparison with an existing database of cases until 1997.

RESULTS

Of 857 documented cases of CPT (median patient age at diagnosis, 3 years), 347 were CPC, 15 atypical choroid plexus papilloma (APP), and 495 choroid plexus papilloma (CPP). Histology was a significant prognostic factor (P < .0001; log rank). Within the subgroup of patients with CPC, both surgery and irradiation were linked to a better prognosis (P < .005). The 104 CPC patients who received chemotherapy had a statistically better survival than those without chemotherapy (P = .0004). When subgroups were defined by radiation treatment, chemotherapy remained beneficial in the subgroup of nonirradiated tumors (P = .0001). The benefit of chemotherapy was also significant when the analysis was restricted to the subgroup of patients with less than completely resected CPC (2-year overall survival (OS) 54.8 +/- 7% (standard deviation (SD) vs. 24.4 +/- 7%, P < .0001) and when this subgroup was further divided into smaller subgroups. Likewise, in a multivariate analysis, chemotherapy was highly significantly linked to better prognosis (P = .0001).

CONCLUSION

Patients with less than completely resected CPC should receive chemotherapy.

Phase I trial of intrathecal spartaject busulfan in children with neoplastic meningitis: a Pediatric Brain Tumor Consortium Study (PBTC-004)

PURPOSE

A phase I trial of intrathecal Spartaject Busulfan (SuperGen, Inc., San Ramon, CA) was conducted in children with neoplastic meningitis following recurrent primary brain tumors to describe toxicities, estimate the maximum tolerated dose (MTD), and document evidence of responses to this agent.

EXPERIMENTAL DESIGN

The continuous reassessment method was used to assign cohorts of patients to doses of intrathecal Spartaject Busulfan via an Ommaya reservoir and/or lumbar puncture twice weekly for 2 weeks followed by an assessment of toxicity and response. Patients with stable disease or an objective response continued to receive intrathecal Spartaject Busulfan plus systemic chemotherapy at regular intervals. Cerebrospinal fluid and blood were obtained for pharmacokinetic studies in patients with Ommaya reservoirs after the first dose of intrathecal Spartaject Busulfan. Seven evaluable patients were assigned to the starting dose of 5 mg, two patients to 7.5 mg, three patients to 10 mg, seven patients to 13 mg, and four patients to 17 mg.

RESULTS

Between September 2000 and May 2003, 28 patients were enrolled in this study. Twenty-three patients (median age, 8.8 years; range, 2.5-19.5 years) were evaluable for estimating the MTD, and dose-limiting toxicities were observed in three and included grade 3 vomiting (n = 1 at 5 mg), grade 3 headache (n = 1 at 17 mg), and grade 3 arachnoiditis (n = 1 at 17 mg). Pharmacokinetic data showed that post-infusion concentrations of busulfan ranged from 50 to 150 microg/mL and declined to <1 microg/mL within 5 hours.

CONCLUSIONS

Intrathecal Spartaject Busulfan was well tolerated in children with neoplastic meningitis from brain tumors, and the recommended dose for future phase II studies is 13 mg.

[Choroid plexus tumors: report of 7 cases in a single institution]

The management of seven patients with choroid plexus tumors, 4 adults and 3 children (mean age 17.5 years) at our institution was reviewed. There were 4 cases of papilloma and 3 of carcinoma located in the lateral ventricle in 1 case, the third ventricle in 1 case, and the fourth ventricle in 5 cases. Total surgical excision was attempted in all patients. Total resection was achieved in three patients, resulting in no deficit in two and persistence of preoperative dysphagia in one. There was no recurrence after total resection. Subtotal resection was achieved in four patients, one of whom underwent second surgery resulting in total resection, and one patient died of respiratory disturbance after the third operation because of regrowth of the tumor. Complete excision could not be achieved in 3 of the 5 tumors located in the fourth ventricle because of extension to the brainstem. The median survival was 59.5 months for patients with papilloma, and 67.7 months for those with carcinoma. Adjuvant therapy was also required for carcinoma, one patient was treated by radiotherapy, and two by radiotherapy plus chemotherapy. Only one patient with papilloma was treated by radiotherapy plus chemotherapy postoperatively.

Choroid plexus carcinoma in the adult: is there a role for chemotherapy?

Choroid plexus carcinoma is a rare primary brain neoplasm arising from epithelial differentiated tissue, originating from the choroids plexus of the ventricles and, in 90% of the cases, in the lateral and fourth ventricles. This neoplasm is seen mainly in children and reported infrequently in adults. The treatment of choroid plexus carcinoma is based on scarce evidence in literature. We report a rare case of an adult woman affected by a choroid plexus tumour and a discussion on the therapeutic management of this uncommon adult malignancy.

Successful treatment of an unresectable choroid plexus carcinoma in a patient with Li-Fraumeni syndrome

Choroid plexus carcinoma (CPC) is an uncommon central nervous system tumor requiring complete surgical excision for favorable outcome. The authors report the successful treatment of a 2-year-old patient with widely disseminated CPC and Li-Fraumeni syndrome. Following a partial resection of the tumor the patient received chemotherapy consisting of cyclophosphamide, etoposide, and carboplatin. There were no additional surgical procedures and radiation was not administered. Remarkably, the patient remains without evidence of active disease more than 3 years from the completion of therapy. Additional studies are necessary to determine whether this treatment plan can be beneficial to other patients with CPC and whether the patient's p53 mutation had an effect on outcome.

Leukoencephalopathy around a tumor cyst following intracystic methotrexate injection

A 4-year-old female with choroid plexus carcinoma developed progressive disturbance of consciousness 2 years after postoperative treatment with radiotherapy, chemotherapy, and focal methotrexate injection into a residual tumor cyst. Magnetic resonance imaging revealed white matter lesions localized around the expanding large cyst. A malignant recurrence of choroid plexus carcinoma with a propensity of cerebrospinal fluid overproduction was suspected. However, daily drainage of cerebrospinal fluid from the cyst and treatment with glycerol and dexamethasone achieved improvement. Diffuse hypoperfusion over the lesions on single-photon emission computed tomography denied the possibility of residual tumor aggravation and together with subsequent atrophic changes confirmed that the lesions reflect localized leukoencephalopathy, possibly associated with methotrexate forced into the parenchyma as a result of the expanding intracystic high pressure.

Intrinsic brainstem choroid plexus papilloma

✓ The authors report an intrinsic brainstem lesion that was diagnosed initially as a pontine cavernoma, which finally proved to be a choroid plexus papilloma. Choroid plexus papillomas are rare tumors of the central nervous system and are usually intraventricular in location. The occurrence of this tumor in an intraparenchymal location is extremely rare, and its occurrence within the brainstem is previously unreported. The authors also report a trial of chemotherapy with lomustine in the management of the residual tumor.

Efficacy of sequential chemotherapy including methotrexate and doxorubicin in an infant with partially resected choroid plexus carcinoma

This report refers to a 3-month-old male, with a residual choroid plexus carcinoma following partial resection, who was successfully treated with sequential chemotherapy without any postoperative radiation therapy. Along with carboplatin, we also used doxorubicin and methotrexate, hypothesizing that, given the patient's age, the blood-brain barrier should not hamper drug delivery to the tumor. According to this hypothesis, the treatment achieved complete remission of the disease, which lasts 27 months after the diagnosis. This result deserves further studies to assess the possible curative role of chemotherapy in very young patients suffering from choroid plexus carcinoma.

[A study of usefulness of chemotherapy in long-term survival choroid plexus carcinoma case of childhood]

We report a girl who was diagnosed with choroid plexus carcinoma at the age of 7 and has had an active daily life in the 11 years after onset. She underwent two tumor excision operations and received radiotherapy followed by intensive chemotherapy using cisplatin, carboplatin, and etoposide. In general, the prognosis of choroid plexus carcinoma is very poor, especially in the childhood cases, since no optimal treatment for choroid plexus carcinoma has yet been established. However, the results of analyses of the present long-term survival case, and similar long-term survival cases in the literature, strongly suggest the usefulness of chemotherapy in the treatment of choroid plexus carcinoma in children.

Is there a requirement for adjuvant therapy for choroid plexus carcinoma that has been completely resected?

Choroid plexus carcinomas (CPC) are rare central nervous system malignancies. While attempted surgical resection is imperative, the benefit of adjuvant therapy, particularly in the setting of a gross total resection (GTR), is unclear. We reviewed all pediatric cases of CPC reported in the literature between 1985 and 2000. Seventy-five cases of CPC were identified. Mean age at the time of diagnosis was 26 months. Thirty-seven patients had a GTR and 38 patients had a subtotal resection (STR). Thirty-eight cases (51%) were alive and 37 cases (49%) were deceased at time of publication. For cases with a GTR, survival was 84% compared to an 18% survival for patients with a STR. For patients with a GTR, all forms of adjuvant therapy were statistically equivalent. Our retrospective literature review confirms the importance of GTR in the therapy of CPC, with GTR alone being the single most important predictor of survival. The prognosis is poor for any patient with a STR, with the exception of those patients for whom adjuvant therapy allowed for an eventual GTR. The small number of patients receiving a GTR and no further therapy precluded a statistical comparison of no therapy in the setting of a GTR versus any form of adjuvant therapy. However, all four of these patients are alive, raising the possibility that adjuvant therapy in the setting of a GTR may not be required.

Evidence of therapeutic efficacy of CCNU in recurrent choroid plexus papilloma

A pregnant 33-year old woman developed nystagmus and cerebellar ataxia. A tumor in the roof of the fourth ventricle was diagnosed. The tumor was subtotally removed using microneurosurgical techniques. The histopathological diagnosis was choroid plexus papilloma (CPP). Twenty-one months later, the tumor recurred and was reoperated. Histologically the tumor displayed now increased mitotic activity and pleomorphism. Radiation therapy of the neuroaxis was performed. Within 59 months, the CPP recurred 3 more times with neuroradiological evidence of extensive spinal seeding. After several palliative irradiations, including 2 gamma-knife boosts, the patient was referred to chemotherapy. She was treated with CCNU (Lomustin) 100 mg/m2 orally (12 cycles, cumulative dosis 1440 mg/m2). Within 42 months, there was no new local recurrence and spinal seeding showed significant regression. Clinically the patient improved and stabilized, but needs continuous support because of persisting severe gait ataxia. The course of disease in our patient provides evidence for therapeutic efficacy of CCNU in recurrent CPP.

Chemotherapy of choroid plexus carcinoma

Choroid plexus carcinoma is a rare and frequently lethal tumor. Its cure depends primarily on the achievement of gross total resection. The contribution of adjuvant therapies, both irradiation and chemotherapy, in the context of gross total resection is unclear, but where such resection is not possible there may be a role for adjuvant therapy to permit more nearly complete resection. In particular, the limitation on resectability is imposed by the friability and extraordinary degree of vascularity, both of which may be favorably influenced by the use of chemotherapy following an initial biopsy, with deferral of the attempt at definitive resection until the impact of chemotherapy has been realized.

Volumetric reduction of a choroid plexus carcinoma using preoperative chemotherapy

We report for the first time a measured volumetric reduction of a choroid plexus carcinoma utilizing preoperative chemotherapy. Histologically proven choroid plexus carcinoma was diagnosed in a fifteen month old female. She was treated with three courses of chemotherapy including etoposide (VP16), cyclophosphamide, vincristine, and cisplatin. Computer-assisted three dimensional reconstruction of the tumor volume was performed prior to and after three courses of chemotherapy. An overall reduction of 29.5% of tumor volume was accomplished preoperatively. Staged surgical procedures resulted in a complete resection of her lesion and she has remained disease-free for 31 months. A volumetric measurement as a response to preoperative chemotherapy may prove valuable in determining future optimal treatment regimens for choroid plexus carcinoma of childhood.

Choroid plexus carcinomas in childhood: clinical features and prognostic factors

OBJECTIVE

Choroid plexus carcinomas are rare tumors with dismal prognosis. The role of surgery has been well established, but the benefit of either chemotherapy or radiotherapy remains controversial. To determine prognostic factors and effects of different therapeutic modalities on the outcome, we have reviewed the French experience of choroid plexus carcinoma.

METHODS

Twenty-two children were registered in the Société Française d'Oncologie Pédiatrique between 1984 and 1995. All these children underwent surgical resection of the primary tumor. The intent of postoperative treatment was to delay or to avoid radiation therapy. Nineteen children received postoperative treatment, with chemotherapy in 17 and radiation therapy in 2. Two responding patients underwent high-dose chemotherapy with stem cell rescue.

RESULTS

The 5-year survival rate was 26%. The sole relevant prognostic factor was the extent of surgery. Patients with total or gross total resection had a 86% survival rate. Survival did not correlate with age, sex, delay between first appearance of symptoms and diagnosis, location of the primary tumor, tumor volume, or response to postoperative treatment. All but one patient with incomplete surgery had tumor recurrence within 2 to 23 months.

CONCLUSION

Choroid plexus carcinoma has a very poor prognosis when surgery is incomplete. Aggressive surgical resection of the tumor is necessary for survival. Although chemotherapy gives promising responses, local control remains the main challenge, and "second look" surgery has to be considered for patients with incomplete resection.

Neoadjuvant chemotherapy for hypervascular malignant brain tumors of childhood

Some large hypervascular brain tumors pose an exceptional challenge to surgical resection, particularly in young children with small blood volumes. To limit blood loss during resection of hypervascular tumors, the authors used upfront chemotherapy as the primary treatment modality in 2 young children. This produced a dramatic reduction in tumor size and vascularity and greatly facilitated definitive surgical removal.

[A case report of choroid plexus carcinoma]

Choroid plexus carcinoma (CPC) is a rare tumor with poor prognosis, whose optimal treatment has not yet been established. We report a case of a one-year-old infant who has been treated with successive combined therapy. The therapy involved two operations for partial removal, interrupted radiotherapy up to 12Gy, 2 cycles of salvage chemotherapy, followed by an operation for total removal, and then a further 3 cycles of chemotherapy. CT scan after the preoperative salvage chemotherapy showed remarkable shrinkage of the residual tumor, which made operative procedure easier. The patient was disease-free for ten months after the last operation. Patients with combined preoperative chemotherapy and total resection seem to enjoy prolonged progression-free survival, so preoperative chemotherapy for choroid plexus carcinoma seems to be of benefit, despite the fact that its optimal recipe has not yet been established.

Postoperative chemotherapy and delayed radiation in infants and very young children with choroid plexus carcinomas. The Pediatric Oncology Group

Eight infants with choroid plexus carcinomas were treated with surgery, prolonged postoperative chemotherapy and delayed radiation. The results suggest that some infants with choroid plexus carcinomas can be successfully treated with multimodality therapy, even allowing children with less than a gross total resection to have prolonged disease-free intervals.

A phase II study of every other day high-dose ifosfamide in pediatric brain tumors: a Pediatric Oncology Group Study

Despite reported activity in many other solid tumors, high-dose ifosfamide produces few objective responses in recurrent pediatric brain tumors. Alkylating agents such as cyclophosphamide (CYCLO) possess good activity in many of solid tumors, including brain tumors. Although Ifosfamide (IFOS), a structural congener of CYCLO, has been suggested to have greater activity in several tumors, its activity in brain tumors is uncertain. We conducted a phase II trial of every-other day IFOS (3 gm/M2/qod x 3) in 87 recurrent pediatric brain tumors. Responses were evaluable in 71 patients. Partial responses occurred in 1/6 patients with low grade astrocytoma, 1/16 with malignant glioma, 1/16 with medulloblastoma, 1/3 with pineoblastoma and 1/12 patients with ependymoma. No responses occurred among 10 patients with brain stem gliomas or 8 patients with other brain tumors. Despite the poor objective response rate, 23/71 patients were clinically and imaging stable for periods of 8-62 weeks. There was no relationship between prior CYCLO treatment and subsequent response or failure with IFOS. The predominant toxicity was myelosuppression. Although generally reversible, prolonged suppression and sepsis were responsible for the deaths of 3 heavily pretreated patients. Renal toxicity was uncommon; 2 patients had grade III, and one grade IV renal tubular dysfunction. One patient had grade IV hematuria. Neurotoxicity was less common than in studies of daily ifosfamide; only 1 patient had grade IV neurotoxicity. Three patients had grade III or IV IFOS related hyponatremia. Despite the good stable disease rate, the poor rate of objective response suggests that IFOS monotherapy possesses little clinically meaningful activity in brain tumors.

The treatment of malignant scala posterior tumors in children: II. Preliminary result of the pre- and postoperative adjuvant chemotherapy of scala posterior tumors

Ten children with posterior scala tumor infiltrating the surrounding brain substance and/or the brain stem entered in the present study with preoperative chemotherapy. In 8 of the 10 cases regression and necrosis of the tumor were seen by CT examination after the preoperative therapy. The diameter of the tumor decreased on the average by 35.6% (14.0-74.3%). The main side effect was granulocytopenia. According to our observation, the preoperative therapy enables a more radical surgery in some cases of medulloblastoma and ependymoma. Further observations are necessary to confirm these preliminary results.

Choroid plexus tumors in childhood. Response to chemotherapy, and immunophenotypic profile using a panel of monoclonal antibodies

Clinical and immunophenotypic (IP) data are presented on three children with choroid plexus (CP) tumors. Two children ages 0.2 and 2 years old with histologically proven malignant tumors had subtotal tumor resections and were treated with ten monthly cycles of eight-drugs-in-1-day chemotherapy without radiation therapy (XRT). Both are free of tumor 4 and 7 years later. The literature on survival of children with CP carcinomas after chemotherapy and XRT is reviewed. Monoclonal antibodies to 17 neuroectodermal, neuronal, glial, and leukocytic markers on frozen sections were used to IP the two malignant tumors and a CP papilloma. All tumors expressed two neuroectodermal markers (PI-153/3 and UJ 223.8), cytokeratin 19, and a neural and leukocyte marker (Thy-1). Two of three expressed neurofilament protein (NF-H) and glial fibrillary acidic protein (GFAP) and one expressed NF-M and common leukocyte antigen. None had strong expression for the panneuroectodermal antigen UJ13/A. There was variable expression of the other markers. The most common IP profile for CP tumors (cytokeratin 18+, PI-153/3+, Thy-1+, UJ 223.8+, and GFAP+ and UJ13A-, UJ 127.11-, and NF-L-) is discussed in the context of the current knowledge of the ontogenetic origin of the CP. It was concluded that chemotherapy for malignant CP tumors can be associated with long-term survival in young children and that the unique IP profile of CP tumors with coexpression of three intermediate filaments suggests new and provocative evidence of their cellular complexity and heterogeneity.

Choroid plexus carcinoma--responses to chemotherapy alone in newly diagnosed young children

Choroid plexus carcinoma (CPC) arising in the infant poses several treatment dilemmas. The tumor is often not totally resectable at presentation given its large size and tendency to invade adjacent brain. Because of its predisposition to regrow and metastasize, some form of postoperative cytotoxic therapy is required. Chemotherapy (CHT), as opposed to radiotherapy (RT), has a more desirable risk/benefit role in infants, since it is relatively sparing of late neurologic sequelae. Three young male children presented with large intraventricular CPC at 9, 18, and 27 months of age. One child had subarachnoid metastases at diagnosis and the other two had localized disease. Subtotal resections were accomplished and all three required VP shunts. Initial CHT consisted of four monthly courses of cisplatin (20 mg/m2) and etoposide (100 mg/m2), both administered intravenously, daily, for five days. After four courses, two children had complete responses and one had stable disease. Additional CHT was given but one child developed a local recurrence and another diffuse CNS metastases. Both died with intratumoral hemorrhages at 5 and 57 months following diagnosis. The third child remains in continuous remission 46 months after diagnosis. None of the children received RT. Chemotherapy may permit long term deferral of RT. More aggressive CHT regimens should be explored in infants with CPC.

Volumetric analyses of central nervous system neoplasm based on MRI

Morphometric analyses were performed using an objective semiautomated algorithm on 5 sequential three-dimensional T1-weighted magnetic resonance imaging scans of a metastatic choroid plexus carcinoma, concurrent with a course of chemotherapy. The 5 scans were positionally normalized in a three-dimensional coordinate system for uniform definition of the borders of the mass. Volumes were calculated for the gadolinium-DTPA enhancing and nonenhancing cystic-appearing regions. Volumetric changes of up to 145% were measured using this method which were associated with changes in the calculated (spherical) radii of only up to 2.7 mm. Volumetric changes of up to 59% were not appreciated by visual inspection, most probably due to irregular borders and positional variability across the scans. Volumetric analyses were also performed on the right cerebellar hemisphere, producing a 1.83% coefficient of variability across the 5 scans. The growth rates of this mass were estimated from the sequential computations, permitting in vivo observations on tumor behavior otherwise not obtainable. These analyses demonstrate the potential of this morphometric method to detect significant volumetric changes, and illustrate its use to define in vivo the growth properties of central nervous system tumors in response to therapeutic interventions.

Current management of choroid plexus carcinoma in children

Eleven children with choroid plexus carcinoma are reviewed with respect to presentation, radiographic diagnosis, treatment and pathologic histology. These cases accumulated over a 33-year period and represent 39% of all of our choroid plexus tumors (n = 28). Characteristically, choroid plexus carcinomas are associated with a poor prognosis for long-term survival. Unfortunately, efforts at total resection are hindered in part by the extreme vascularity of the tumor which itself may be of considerable volume. We have recently treated four children who had biopsy or minimal resection of their tumor after which adjuvant chemotherapy was given. Chemotherapy is not curative but it does cause a reduction in tumor volume and, more importantly, has tended to reduce the tumor vascularity. This allows for a second stage operation which is more safely performed and typically allows for more complete tumor removal. At this point, our length of follow-up is insufficient to conclude if total removal in this manner significantly increases survival but it would seem that consistent gross total removal may be an initial step toward better overall management and prognosis in this tumor type.