Which therapy works better in choroid plexus carcinomas?

Choroid plexus carcinomas (CPCs) are rare tumors with dismal outcome. While it has been established that surgery, radiotherapy, and chemotherapy improve survival, the best chemotherapy drugs for treating this disease still need to be identified. Since CPC is too rare to permit a prospective clinical trial, we performed a meta-analysis to evaluate the effects of individual drugs in patients with CPCs.

Cribriform neuroepithelial tumor (CRINET): a nonrhabdoid ventricular tumor with INI1 loss and relatively favorable prognosis.

Atypical teratoid/rhabdoid tumors are malignant embryonal tumors characterized by the presence of rhabdoid cells, genetic alterations affecting the SMARCB1 gene (hSNF5/INI1), and a poor prognosis. Whether INI1 plays a role in the pathogenesis of other central nervous system tumors is uncertain. We report on cases of 2 young children with unusual intracranial nonrhabdoid neuroectodermal tumors within and around the third or fourth ventricle that are characterized by cribriform strands and trabeculae and well-defined epithelial membrane antigen-immunopositive surfaces and show INI1 protein loss.

Platelet-derived growth factor receptor expression and activation in choroid plexus tumors.

Choroid plexus tumors are intraventricular neoplasms predominantly affecting young children. In contrast to choroid plexus papillomas, choroid plexus carcinomas progress frequently, necessitating the development of adjuvant treatment concepts. Platelet derived growth factor (PDGF) signaling has been shown to support growth in a variety of tumors.

Role of Wnt inhibitory factor-1 and Wnt/wingless signaling in choroid plexus tumors.

Little is known on pathways involved in the pathogenesis of choroid plexus tumors (CPTs). The finding of overexpression of Wnt inhibitory factor-1 (Wif-1) prompted us to investigate the functional role of Wif-1 as well as nuclear accumulation of beta-catenin in CPT. In Z310 neoplastic choroid plexus epithelial cells, silencing of Wif1 expression increased proliferative activity not associated with increased canonical Wnt signaling.

Atypical choroid plexus papilloma: clinical experience in the CPT-SIOP-2000 study.

Atypical choroid plexus papilloma (APP) represents a novel intermediate-grade subtype of choroid plexus tumor (CPT), the clinical outcome of which has not been described yet. We present the first analysis of a group of APP patients enrolled in the ongoing CPT-SIOP-2000 study of CPTs. A worldwide registration and a randomized trial for those patients who require chemotherapy started in 2000.

TWIST-1 is overexpressed in neoplastic choroid plexus epithelial cells and promotes proliferation and invasion.

The pathogenesis of choroid plexus papillomas, intraventricular papillary neoplasms most often occurring sporadically in children and young adults, remains poorly understood. To identify pathways operative in the development of choroid plexus papillomas, gene expression profiles obtained from laser-microdissected human choroid plexus papilloma cells (n = 7) were compared with that of normal choroid plexus epithelial cells laser microdissected from autopsy tissue (n = 8). On DNA microarray data analysis, 53 probe sets were differentially expressed in choroid plexus papilloma tumor cells (>7-fold).

Aberrant MGMT (O6-methylguanine-DNA methyltransferase) promoter methylation in choroid plexus tumors.

Aberrant methylation of the MGMT (O6-methylguanine-DNA methyltransferase) DNA-repair gene is a predictive marker for the response to chemotherapy with alkylating agents (e.g., temozolomide) in malignant gliomas.

Platelet-derived growth factor receptor expression and amplification in choroid plexus carcinomas.

Platelet-derived growth factor (PDGF) receptor signaling has been implicated in the development of glial tumors, but not yet been examined in choroid plexus carcinomas, pediatric tumors with dismal prognosis for which novel treatment options would be desirable. Therefore, protein expression of PDGF receptors alpha and beta as well as amplification status of the respective genes, PDGFRA and PDGFRB, were examined in a series of 22 patients harboring choroid plexus carcinoma using immunohistochemistry and chromogenic in situ hybridization (CISH). The majority of choroid plexus carcinomas expressed PDGF receptors with 6 cases (27%) displaying high staining scores for PDGF receptor alpha and 13 cases (59%) showing high staining scores for PDGF receptor beta.

Malignant progression in choroid plexus papillomas.

Object: Malignant progression of choroid plexus papillomas has been occasionally reported, but this issue has not yet been systematically addressed.

Methods: Frequency and extent of malignant progression were examined in a retrospective series of 124 primary choroid plexus papillomas using uniform histological criteria.

Results: After gross-total resection and a mean follow-up period of 59 months, 12 recurrences necessitating neurosurgical intervention had occurred in the 103 cases of choroid plexus papilloma (World Health Organization [WHO] Grade I) and 21 cases of atypical choroid plexus papilloma (WHO Grade II).

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.

Prognostic implications of atypical histologic features in choroid plexus papilloma.

The prognostic significance of atypical histologic features in choroid plexus tumors remains uncertain. Therefore, a series of 164 choroid plexus tumors was evaluated for the presence of atypical histologic features, including mitotic activity, increased cellularity, nuclear pleomorphism, blurring of papillary growth pattern, and necrosis. The impact of histopathologic and clinical features on the probability of recurrence and survival was investigated.

Second surgery and the prognosis of choroid plexus carcinoma--results of a meta-analysis of individual cases.

Tumors of the choroid plexus (CPT) are rare. While choroid plexus papillomas (CPP) are regarded as benign, choroid plexus carcinomas (CPC) have a dismal prognosis, and there is limited information available regarding the best treatment. Maximal possible surgery is generally believed to be the major prognostic factor, but data to answer the question, of whether second surgery improves the prognosis of CPC have been missing.