No abstract

Stromal cell-derived Factor-1a (SDF-1a) stimulates the migration of bone marrow (BM) cells, similar to vascular endothelial growth factor (VEGF). We previously demonstrated that inhibition of VEGF 165 by small interfering RNA inhibited Ewing's sarcoma tumor growth, tumor vessel formation and recruitment of BM cells to the tumor. To determine the importance of BM cells in tumor vessel development, we investigated the effects of SDF-1a on VEGF-inhibited TC/siVEGF 7-1 Ewing's tumor neovasculature formation and growth. The effect of SDF-1a on CD34 1 progenitor cell chemotaxis was determined in vivo. Using a BM transplantation model with GFP 1 transgenic mice as BM donors and nude mice as recipients, we evaluated the effect of SDF-1a on the recruitment of BM-derived cells to VEGF 165 -inhibited TC/ siVEGF 7-1 tumors, as well as its effect on neovasculature development, vessel morphology and tumor growth. SDF-1a stimulated the migration of CD34 1 progenitor cells to Matrigel plugs in vivo and promoted the retainment of BM-derived pericytes in close association with perfused, functional tumor vessels. Intratumor inoculation of Ad-SDF-1a into TC/siVEGF 7-1 tumors resulted in increased SDF-1 and PDGF-BB expression, augmented tumor growth, an increase in the number of large, lumen-bearing vascular structures, and enhanced vessel pericyte coverage, with no change in VEGF 165 . SDF-1a stimulates BM cell chemotaxis and the association of these cells with functional tumor vessels. Furthermore, SDF-1a enhances tumor neovascularization and growth with no alteration in VEGF 165 . Our work suggests that SDF-1-mediated vasculogenesis may represent an alternate pathway that could potentially be utilized by tumors to sustain growth and neovasculature expansion after anti-VEGF therapy. '

The data demonstrate that an ALC > or =500 cells/microL on day 15 of the first course of chemotherapy is an independent prognostic factor associated with superior OS in high-risk Ewing sarcoma.

Introduction Immune tolerance induction (ITI) is the gold standard for eradication of factor VIII inhibitors in severe haemophilia A; however, it usually requires treatment for extended periods with associated high burden on patients and healthcare resources. Aim Review outcomes of ITI with recombinant factor VIII Fc fusion protein (rFVIIIFc) in patients with severe haemophilia A and high‐titre inhibitors. Methods Multicentre retrospective chart review of severe haemophilia A patients treated with rFVIIIFc for ITI. Results Of 19 patients, 7 were first‐time ITI and 12 were rescue ITI. Of 7 first‐time patients, 6 had at least 1 high‐risk feature for ITI failure. Four of 7 first‐time patients were tolerized in a median of 7.8 months. The remaining 3 patients continue on rFVIIIFc ITI. Of 12 rescue patients, 7 initially achieved a negative Bethesda titre (≤0.6) in a median of 3.3 months, 1 had a decrease in Bethesda titre and continues on rFVIIIFc ITI and 4 have not demonstrated a decrease in Bethesda titre. Of these 4, 3 continue on rFVIIIFc ITI and 1 switched to bypass therapy alone. Two initially responsive patients transitioned to other factors due to recurrence. Overall, 16 of 19 patients remain on rFVIIIFc (prophylaxis or ITI). For those still undergoing ITI, longer follow‐up is needed to determine final outcomes. No adverse events reported. Conclusions Recombinant factor VIII Fc fusion protein demonstrated rapid time to tolerization in high‐risk first‐time ITI patients. For rescue ITI, rFVIIIFc showed therapeutic benefit in some patients who previously failed ITI with other products. These findings highlight the need to further evaluate the use of rFVIIIFc for ITI.

SummaryThe purpose of this study was to determine whether a correlation exists between tumor cyclooxygenase (COX)-2 expression and disease-specific survival in patients with osteosarcoma lung metastases. Thirty-six patients diagnosed with osteosarcoma lung metastases between the years 1990 and 2001 were included in this retrospective study. The majority of the patients (72%) presented newly -diagnosed osteosarcoma lung metastases whereas the remaining patients (28%) presented recurrent disease. Clinicopathologic parameters were obtained from patients' clinical records. Tissue samples were obtained at the time of resection of the lung metastases and stained for COX-2 using immunohistochemistry. Samples were graded according to the intensity of COX-2 staining (grade 0: negative, grade 1: very weak, grade 2: weak, grade 3: moderate, and grade 4: strong). COX-2 staining was correlated with disease-specific survival and clinicopathologic parameters using the Jonckheere-Terpstra and the Kruskal-Wallis tests. All patients with grade 3 or 4 COX-2 expression died of osteosarcoma lung metastases. Ten percent of patients with grade 2 COX-2 expression and 29% of patients with grade 1 expression were alive and free of disease at the last follow-up. By contrast, 60% of the patients with grade 0 COX-2 expression were alive and free of disease at the last follow-up. No association between COX-2 expression and clinicopathologic parameters was found. However, COX-2 expression correlated inversely with disease-specific survival in patients with osteosarcoma lung metastases. Our data indicate that COX-2 expression in metastatic osteosarcoma may have prognostic significance. KeywordsCOX-2; osteosarcoma; lung metastases Soft tissue and bone sarcomas comprise nearly 13% of all cancers in childhood. Approximately 1500 new cases of pediatric sarcoma are diagnosed each year in the United States.1 For osteosarcoma, the most common primary tumor site is the metaphysis of long bones, and the most common site of metastatic involvement is the lungs. Patients with Reprints: Nidra I. Rodriguez, MD, Children