Angiogenesis is necessary for tumor growth. Drug discovery efforts have identified several potential therapeutic targets on endothelial cells and selective inhibitors capable of slowing tumor growth or producing tumor regression by blocking angiogenesis in in vivo tumor models. Certain antiangiogenic therapeutics increase the activity of cytotoxic anticancer treatments in preclinical models. More than 75 antiangiogenic compounds have entered clinical trials. Most of the early clinical testing was conducted in patients with advanced disease resistant to standard therapies. Several phase III trials have been undertaken to compare the efficacy of standard chemotherapy versus the same in combination with an experimental angiogenesis inhibitor. Preliminary results of the clinical studies suggest that single-agent antiangiogenic therapy is poorly active in advanced tumors. Although some of the results of combination trials are controversial, recent positive outcomes with an antivascular endothelial growth factor antibody combined with chemotherapy as front-line therapy of metastatic colorectal cancer have renewed enthusiasm for this therapeutic strategy. This article presents an overview of experimental and clinical studies of combined therapy with antiangiogenic agents and highlights the challenges related to the appropriate strategies for selection of the patients, study design, and choice of proper end points for preclinical and clinical studies using these agents.

Samples of lymph nodes from 88 patients with B‐cell non‐Hodgkin's lymphoma (B‐NHL) grouped by the Working Formulation (WF) and from 15 patients with benign lymphadenopathies were investigated immunohistochemically and ultrastructurally for changes in angiogenesis and stromal distribution of two subendothelial basement membrane (BM) components, namely laminin and type IV collagen. The microvessel number was usually low in lymphadenopathies, and increased significantly in low‐grade B‐NHL. Intermediate‐grade tumors displayed a further significant increase that was mainly due to their diffuse subtypes rather than to the follicular subtype. High‐grade B‐NHL showed the highest counts. By contrast with the lymphadenopathies studied, the stroma of B‐NHL reacted intensely with both BM components, whose linear co‐expression was significantly associated with low‐grade and follicular intermediate‐grade B‐NHL, while expression of laminin alone in a granular pattern was detected in diffuse intermediate‐grade and high‐grade tumors. Ultrastructural analysis revealed immature vessels more frequently in diffuse intermediate‐grade, and in high‐grade B‐NHL. These in situ data suggest that angiogenesis occurring in B‐NHL increases along their progression path, and emphasize the importance of angiogenesis as an epigenetic phenomenon of B‐NHL progression.

Apocrine carcinoma of the skin is a rare tumor. Wide surgical excision with complete removal of the neoplasm is the standard therapy and this appears to offer the best chance of cure. Radiotherapy may be used in case of local relapse or regional lymph node involvement. Systemic chemotherapy has not proved to be effective in the treatment of this tumor. We report on a 46-year-old woman with a recurrent apocrine carcinoma of the scalp that had previously been treated with surgery, radiotherapy and chemotherapy (Al-Saraff schedule). The patient was responsive to a second-line systemic chemotherapy regimen consisting of a weekly combination of methotrexate and bleomycin, and achieved long-term progression-free survival.

Objective: Thrombospondins (TSP_s) are a multigene family of five secreted glycoproteins involved in the regulation of cell proliferation, adhesion and migration.Two members of the TSP family, namely TSP-1 and TSP-2, are also naturally occurring inhibitors of angiogenesis. The aim of the present study was to determine the prognostic significance of the determination of TSP-1 and -2 and their correlation with the angiogenic peptides vascular endothelial growth factor (VEGF) and thymidine phosphorylase (TP), as well as with other biological and clinicopathological features investigated. Methods: We evaluated a series of 168 women with node-negative breast cancer with a median follow-up period of 66 months, not treated with adjuvant therapy. The cytosolic levels of TSP-1 and -2 were determined in the primary tumour by a commercially available immunometric assay. Results: We found that 166 tested tumours had measurable levels of TSP-1 and -2 protein (median value 5.978, range 0.579–31.410 ng/mg of protein). On the basis of Spearman’s rank correlation coefficient, a weak inverse association of TSP-1 and -2 with tumour size and cathepsin D was found. Moreover, principal component analysis on ranks evidenced a poor association between TSP-1 and -2, VEGF and TP. The results of the clinical outcome were analysed by both univariate and multivariate [for relapse-free survival (RFS) only]) Cox regression models. TSP-1 and -2 were not significant prognostic factors in univariate analysis for either RFS (p = 0.427) or overall survival (p = 0.069). To investigate the ‘angiogenic balance hypothesis’, bivariate analyses were performed to investigate the interactions of TSP-1 and -2 with VEGF, TP or p53, but none were included in the selected models. Finally, in multivariate analysis for RFS a baseline model, previously defined in a larger case series and inclusive of VEGF, TP and their interaction was adopted. It was highly significant (p = 0.002, Harrell c statistic value of 0.703); but when TSP-1 and -2 were added, their contribution was negligible (p = 0.731, Harrell c statistic value of 0.705). Conclusions: The results of this study suggest that TSP-1 and -2 do not provide additional prognostic contribution to the joint effects of VEGF and TP. In the series of node-negative breast cancer patients investigated, determination of the angiogenic peptides VEGF and TP gave significant prognostic information. On the contrary, TSP-1 and -2, potential naturally occurring negative regulators of angiogenesis, lacked of prognostic value.

Although hepatitis C virus (HCV) mainly affects hepatocytes, infection is widespread and involves immunologically privileged sites. Whether lymphoid cells represent further targets of early HCV infection, or whether other cells in the hematopoietic microenvironment may serve as a potential virus reservoir, is still unclear. We studied whether pluripotent hematopoietic CD34+ cells support productive HCV infection and can be used to establish an in vitro infection system for HCV. Six patients were selected as part of a cohort of HCV chronic carriers who developed a neoplastic disease. Reverse transcriptase-polymerase chain reaction (RT-PCR) and branched DNA signal amplification assays were used to detect and quantitate HCV RNA in extracted nucleic acids from purified bone marrow and peripheral blood CD34+ cells. Direct in situ RT-PCR, flow cytometry analysis, and immunocytochemistry were applied to demonstrate specific viral genomic sequences and structural and nonstructural virus-related proteins in intact cells. Results indicated that both positive and negative HCV RNA strands and viral proteins were present in CD34+ cells from all HCV-positive patients and in none of the controls. Additional experiments showed that a complete viral cycle took place in CD34+ cells in vitro. Spontaneous increases in viral titers indicated that virions were produced by infected hematopoietic progenitor cells. To further define the cellular tropism, we attempted to infect CD34+ cells in vitro. We were unable to demonstrate viral uptake by cells. These findings suggest that HCV replication can occur in the early differentiation stages of hematopoietic progenitor cells, and that they may be an important source of virus production. © 1998 by The American Society of Hematology.