Purpose: Cancer stem cells (CSC) are thought to represent the population of tumorigenic cells responsible for tumor development. The stem cell antigen CD133 identifies such a tumorigenic population in a subset of glioblastoma patients. We conducted a prospective study to explore the prognostic potential of CSC analysis in glioblastoma patients. Experimental Design: We investigated the relationship between the in vitro growth potential of glioblastoma CSCs and patient death or disease progression in tumors of 44 consecutive glioblastoma patients treated with complete or partial tumorectomy followed by radiotherapy combined with temozolomide treatment. Moreover, we evaluated by immunohistochemistry and immunofluorescence the prognostic value of the relative presence of CD133⁺ and CD133⁺/Ki67⁺ cells in patient tumors. Results:In vitro CSC generation and the presence of ≥2% CD133⁺ cells in tumor lesions negatively correlated with overall (P = 0.0001 and 0.02, respectively) and progression-free (P = 0.0002 and 0.01, respectively) survival of patients. A very poor overall (P = 0.007) and progression-free (P = 0.001) survival was observed among patients whose tumors contained CD133⁺ cells expressing Ki67. Taking into account symptom duration, surgery type, age, O⁶-methylguanine-DNA methyltransferase promoter methylation, and p53 status, generation of CSCs and CD133/Ki67 coexpression emerged as highly significant independent prognostic factors, with an adjusted hazard ratio of 2.92 (95% confidence interval, 1.37-6.2; P = 0.005) and 4.48 (95% confidence interval, 1.68-11.9; P = 0.003), respectively. Conclusions: The analysis of CSCs may predict the survival of glioblastoma patients. In vitro CSC generation and presence of CD133⁺/Ki67⁺ cells are two considerable prognostic factors of disease progression and poor clinical outcome.

Purpose: Few biological prognosticators are useful for prediction of Richter syndrome (RS), representing the transformation of chronic lymphocytic leukemia (CLL) to aggressive lymphoma. Stereotyped B-cell receptors (BCR) may have prognostic effect in CLL progression. We tested the prognostic effect of stereotyped BCR for predicting RS transformation. Experimental Design: The prevalence of stereotyped BCR was compared in RS (n = 69) versus nontransformed CLL (n = 714) by a case-control analysis. Subsequently, the effect of stereotyped BCR at CLL diagnosis on risk of RS transformation was actuarially assessed in a consecutive CLL series (n = 753). Results: RS (n = 69) displayed a higher prevalence of stereotyped BCR (P < 0.001) compared with nontransformed CLL. The actuarial risk of RS transformation was significantly higher in CLL carrying stereotyped BCR (P < 0.001). Among BCR subsets most represented in CLL, subset 8 using IGHV4-39/IGHD6-13/IGHJ5 carried the highest risk of RS transformation [hazard ratio (HR), 24.50; P < 0.001]. Multivariate analysis selected stereotyped BCR (HR, 3.33; P = 0.001) and IGHV4-39 usage (HR, 4.03; P = 0.004) as independent predictors of RS transformation. The combination of IGHV4-39 usage and stereotyped BCR in the same patient identified CLL with a very high risk of RS transformation (5-year risk, 68.7%). The risk carried by stereotyped BCR and IGHV4-39 usage was specific for RS transformation and had no effect on CLL progression without transformation. Conclusions: Analysis of BCR features may help identify CLL patients at risk of RS. A close monitoring and a careful biopsy policy may help early recognition of RS in CLL patients using stereotyped BCR, particularly if combined with IGHV4-39.

Neoplasia publishes the results of novel investigations in all areas of oncology research.

Background: Levels of cell-free circulating DNA have been correlated to clinical characteristics and prognosis in patients with cancers of epithelial origin, while there are no data on patients with B-lymphoproliferative diseases. Patients and methods: Cell-free DNA levels in the plasma samples of 142 patients with lymphomas [45 with Hodgkin's lymphoma (HL), 63 with diffuse large B-cell non-Hodgkin's lymphoma (DLBCL), 24 with follicular, and 10 with mantle cell non-Hodgkin's lymphoma (NHL)] at diagnosis and of 41 healthy individuals were determined using a quantitative PCR for the β-globin gene. Results: Levels of circulating DNA in patients with HL, DLBCL, and mantle cell NHL were significantly higher than in controls (P < 0.01 for all). Increased levels of plasma DNA were associated with advanced stage disease, presence of B-symptoms, elevated lactate dehydrogenase levels, and age >60 years (P = 0.009; <0.0001; <0.0001; 0.04, respectively). In HL, histological signs of necrosis and grade 2 type of nodular sclerosis were associated with increased plasma DNA. Elevated plasma DNA levels were associated with an inferior failure-free survival in patients with HL (P = 0.01) and DLBCL (P = 0.03). Conclusion: Quantification of circulating DNA by real-time PCR at diagnosis can identify patients with elevated levels that are associated with disease characteristics indicating aggressive disease and poor prognosis.

In this study we investigated whether neoplastic transformation occurring in Philadelphia (Ph)–negative myeloproliferative neoplasms (MPNs) could involve also the endothelial cell compartment. We evaluated the level of endothelial colony-forming cells (E-CFCs) in 42 patients (15 with polycythemia vera, 12 with essential thrombocythemia, and 15 with primary myelofibrosis). All patients had 1 molecular abnormality (JAK2^V617F or MPL^W515K mutations, SOCS gene hypermethylation, clonal pattern of growth) detectable in their granulocytes. The growth of colonies was obtained in 22 patients and, among them, patients with primary myelofibrosis exhibited the highest level of E-CFCs. We found that E-CFCs exhibited no molecular abnormalities in12 patients, had SOCS gene hypermethylation, were polyclonal at human androgen receptor analysis in 5 patients, and resulted in JAK2^V617F mutated and clonal in 5 additional patients, all experiencing thrombotic complications. On the whole, patients with altered E-CFCs required antiproliferative therapy more frequently than patients with normal E-CFCs. Moreover JAK2^V617F-positive E-CFCs showed signal transducer and activator of transcription 5 and 3 phosphorylation rates higher than E-CFCs isolated from healthy persons and patients with MPN without molecular abnormalities. Finally, JAK2^V617F-positive E-CFCs exhibited a high proficiency to adhere to normal mononuclear cells. This study highlights a novel mechanism underlying the thrombophilia observed in MPN.