Leonard H. Wexler

Tumour exosome integrins determine organotropic metastasis.

Ever since Stephen Paget’s 1889 hypothesis, metastatic organotropism has remained one of cancer’s greatest mysteries. Here we demonstrate that exosomes from mouse and human lung-, liver- and brain-tropic tumour cells fuse preferentially with resident cells at their predicted destination, namely lung fibroblasts and epithelial cells, liver Kupffer cells and brain endothelial cells. We show that tumour-derived exosomes uptaken by organ-specific cells prepare the pre-metastatic niche. Treatment with exosomes from lung-tropic models redirected the metastasis of bone-tropic tumour cells. Exosome proteomics revealed distinct integrin expression patterns, in which the exosomal integrins α6β4 and α6β1 were associated with lung metastasis, while exosomal integrin αvβ5 was linked to liver metastasis. Targeting the integrins α6β4 and αvβ5 decreased exosome uptake, as well as lung and liver metastasis, respectively. We demonstrate that exosome integrin uptake by resident cells activates Src phosphorylation and pro-inflammatory S100 gene expression. Finally, our clinical data indicate that exosomal integrins could be used to predict organ-specific metastasis.

Second malignancies after Ewing's sarcoma: radiation dose-dependency of secondary sarcomas.

BACKGROUND An excess risk of second malignancies has been reported in survivors of Ewings sarcoma. We examined a multiinstitutional data base to reevaluate the risk among survivors of Ewings sarcoma and to identify possible causal factors. METHODS Information was derived from a data base that included 266 survivors of Ewings sarcoma. Cumulative incidence rates of second malignancies were calculated. Contributions of clinical features, type and dose of chemotherapy, and cumulative radiation dose to the risk of second malignancies were evaluated. RESULTS After a median follow-up duration of 9.5 years (range, 3.0 to 30), 16 patients have developed second malignancies, which included 10 sarcomas (five osteosarcomas, three fibrosarcomas, and two malignant fibrous histiocytomas) and six other malignancies (acute myeloblastic leukemia, acute lymphoblastic leukemia, meningioma, bronchioalveolar carcinoma, basal cell carcinoma, and carcinoma-in-situ of the cervix). The median latency to the diagnosis of the second malignancy was 7.6 years (range, 3.5 to 25.7). The estimated cumulative incidence rates at 20 years for any second malignancy and for secondary sarcoma were 9.2% (SD = 2.7%) and 6.5% (SD = 2.4%), respectively. The cumulative incidence rate of secondary sarcoma was radiation dose-dependent (P = .002). No secondary sarcomas developed among patients who had received less than 48 Gy, while the absolute risk of secondary sarcoma was 130 cases per 10,000 person-years of observation among patients who had received > or = 60 Gy. CONCLUSION The overall risk of second malignancies after Ewings sarcomas is similar to that associated with treatment for other childhood cancers. The radiation dose-dependency of secondary sarcomas justifies modification in therapy to reduce radiation doses.

Gastrointestinal stromal tumors in children and young adults: a clinicopathologic, molecular, and genomic study of 15 cases and review of the literature.

Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors of the intestinal tract that typically occur in adults over the age of 40 years. GISTs in younger patients are rare and not well characterized. The objective was to define the characteristics of GISTs in children and young adults (<30 years old). Clinicopathologic and molecular features, including KIT/PDGFRA genotype, in GISTs from 5 children and 10 young adults were analyzed. Gene expression analysis was performed on 5 gastric tumor samples from 2 children, 2 gastric tumors from young adults, and 10 gastric GISTs from older adults using an U133A Affymetrix platform (22,000 genes). All five pediatric GISTs occurred in girls, involved the stomach as multiple nodules, showed predominantly an epithelioid morphology, often involved lymph nodes, and lacked KIT or PDGFRA mutations. Although all five patients developed recurrence (four in the liver, three in the peritoneum, and two in both sites), four are still alive with disease. Of the 10 GISTs in young adults, half occurred in the small bowel and had spindle cell morphology, and one case had lymph node metastasis. KIT mutations were identified in seven cases, four in exon 11 and three in exon 9. Seven patients developed recurrence, and at last follow-up two patients had died of disease. Gene expression analysis showed high expression of PHKA1, FZD2, NLGN4, IGF1R, and ANK3 in the pediatric and young adult versus older adult cases. GISTs that occur in children are a separate clinicopathologic and molecular subset with predilection for girls, multifocal gastric tumors, and wild-type KIT/PDGFRA genotype. In contrast, GISTs in young adults are a more heterogeneous group, including cases that resemble either the pediatric or the older adult-type tumors. The distinct gene expression profile suggests avenues for investigation of pathogenesis and potential therapeutic strategies.

Ewing Sarcomas With p53 Mutation or p16/p14ARF Homozygous Deletion: A Highly Lethal Subset Associated With Poor Chemoresponse

PURPOSE EWS-FLI1 fusion type, p53 mutation, and homozygous deletion of p16/p14ARF have each been shown to be prognostically significant in Ewing sarcoma (ES). We provide the first combined prognostic analysis of these three molecular parameters in ES. PATIENTS AND METHODS We studied 60 patients with ES (stage: localized in 54, metastatic in six). All cases were confirmed to contain the EWS-FLI1 (29 type 1, 12 type 2, 14 other types) or EWS-ERG fusions (five cases). Homozygous deletion of p16/p14ARF, and p53 mutations were determined by fluorescent in situ hybridization and Affymetrix (Santa Clara, CA) p53 GeneChip microarray hybridization, respectively. RESULTS Eight cases (13.3%) contained point mutations of p53, and eight cases (13.3%) showed p16/p14ARF deletion, including one case with both alterations. Among 32 cases with data on histologic chemoresponse, all 10 with alterations in p53 or p16/p14ARF showed a poor chemoresponse (P = .03). Variables predicting poorer overall survival included p53 mutation alone (P < .001), either p53 or p16/p14ARF alteration (P < .001), and stage (P < .01). In multivariate analysis, alterations of p53 and/or p16/p14ARF as a single variable, was the most adverse prognostic factor (P < .001), followed by stage (P = .04). In a multivariate analysis with alterations of p53 and p16/p14ARF as separate variables, both were significant (P < .001 and P = .03, respectively). Six cases with p16/p14ARF deletion were also studied for co-deletion of the contiguous methylthioadenosine phosphorylase gene, and this was detected in four cases. CONCLUSION Alterations in p53 or p16/p14ARF are found in a fourth of ES cases and define a subset with highly aggressive behavior and poor chemoresponse.

Randomized trial of the cardioprotective agent ICRF-187 in pediatric sarcoma patients treated with doxorubicin.

PURPOSE We conducted an open-label, randomized trial to determine whether ICRF-187 would reduce doxorubicin-induced cardiotoxicity in pediatric sarcoma patients. METHODS Thirty-eight patients were randomized to receive doxorubicin-containing chemotherapy (given as an intravenous bolus) with or without ICRF-187. Resting left ventricular ejection fraction (LVEF) was monitored serially with multigated radionuclide angiography (MUGA) scan. The two groups were compared for incidence and degree of cardiotoxicity, response rates to four cycles of chemotherapy, event-free and overall survival, and incidence and severity of noncardiac toxicities. RESULTS Eighteen ICRF-187-treated and 15 control patients were assessable for cardiac toxicity. ICRF-187-treated patients were less likely to develop subclinical cardiotoxicity (22% v 67%, P < .01), had a smaller decline in LVEF per 100 mg/m2 of doxorubicin (1.0 v 2.7 percentage points, P = .02), and received a higher median cumulative dose of doxorubicin (410 v 310 mg/m2, P < .05) than did control patients. Objective response rates were identical in the two groups, with no significant differences seen in event-free or overall survival. ICRF-187-treated patients had a significantly higher incidence of transient grade 1 serum transaminase elevations and a trend toward increased hematologic toxicity. CONCLUSION ICRF-187 reduces the risk of developing short-term subclinical cardiotoxicity in pediatric sarcoma patients who receive up to 410 mg/m2 of doxorubicin. Response rates to chemotherapy, event-free and overall survival, and noncardiac toxicities appear to be unaffected by the use of ICRF-187. Additional clinical trials with larger numbers of patients are needed to determine if the short-term cardioprotection afforded by ICRF-187 will reduce the incidence of late cardiac complications in long-term survivors of childhood cancer.

Total-body irradiation and autologous bone marrow transplant in the treatment of high-risk Ewing's sarcoma and rhabdomyosarcoma.

PURPOSE In an effort to improve outcome in patients with metastatic or high-risk localized Ewings sarcoma family of tumors (ESF) and rhabdomyosarcoma (RMS), we explored the role of consolidation therapy with total-body irradiation (TBI) plus autologous bone marrow transplantation (ABMT). PATIENTS AND METHODS Ninety-one patients were entered onto one of three consecutive protocols from 1981 to 1986. Induction therapy consisted of four or five cycles of vincristine, doxorubicin, and cyclophosphamide (VAdriaC); in the earlier series, patients received one or two cycles with dactinomycin instead of doxorubicin. Irradiation of the primary site was used for local control. Patients who attained a complete response (CR) to induction therapy were eligible for consolidation with 8 Gy TBI plus VAdriaC and ABMT. RESULTS Nineteen patients were ineligible for consolidation after failing to achieve or maintain a CR following induction therapy; all 19 are dead of disease. Seven eligible patients elected to forgo consolidation; three of seven are long-term event-free survivors. Sixty-five patients received consolidation therapy; 20 of 65 are long-term event-free survivors. A local control rate of 83% was achieved using radiation therapy as the primary modality of local control. Patients with metastatic disease at diagnosis fared substantially worse than did patients with localized tumors (6-year event-free survival [EFS] rate, 14% v 38%; two-sided P [P2] = .008). CONCLUSIONS Consolidation of patients with metastatic or high-risk localized pediatric sarcomas with 8 Gy TBI plus ABMT has failed to improve the outcome of this group of patients. Metastatic disease at diagnosis continues to confer the poorest prognosis. New therapeutic strategies are needed to consolidate more effectively the remissions that can be achieved in the majority of these patients.

EWS-FLI1 and EWS-ERG gene fusions are associated with similar clinical phenotypes in Ewing's sarcoma.

PURPOSE There are a variety of solid tumors in which alternative chromosomal translocations generate related fusion products. In alveolar rhabdomyosarcoma and synovial sarcoma, these variant fusions have been found to have major clinical significance. We investigated whether the two alternative gene fusion products, EWS-FLI1 and EWS-ERG, define different clinical subsets within the Ewings sarcoma family of tumors. PATIENTS AND METHODS We selected 30 cases of Ewings sarcoma with the EWS-ERG gene fusion and 106 cases with the EWS-FLI1 fusion. Clinical data were obtained for each case and compared with the molecular diagnostic findings. RESULTS There were no significant clinical differences observed between the two groups in age of diagnosis, sex, metastasis at diagnosis, primary site, event-free survival, or overall survival. CONCLUSION Differences in the C-terminal partner in the Ewings sarcoma family gene fusions are not associated with significant phenotypic differences.

Long-Term Event-Free Survival After Intensive Chemotherapy for Ewing’s Family of Tumors in Children and Young Adults

PURPOSE To improve the long-term event-free survival of patients with Ewings family of tumors (EFTs) using high-dose, short-term chemotherapy. PATIENTS AND METHODS P6 was a prospective study of previously untreated patients with newly diagnosed EFTs. Patients received seven cycles of chemotherapy. Cycles 1, 2, 3, and 6 consisted of cyclophosphamide 2,100 mg/m2/d on days 1 and 2, and a 72-hour continuous infusion of doxorubicin 75 mg/m2 and vincristine 2 mg/m2 starting day 1. Cycles 4, 5, and 7 consisted of 5 consecutive days of ifosfamide 1,800 mg/m2/d and etoposide 100 mg/m2/d. RESULTS Sixty-eight patients were enrolled from 1991 to 2001 (median age, 18.7 years; range, 3.7 to 39.9 years). At diagnosis, 44 patients had local-regional disease, and 24 had distant metastases. The 4-year event-free survival (EFS) rate for patients with local-regional disease is 82%; overall survival (OS) is 89%. The 4-year EFS rate for patients with distant metastases is 12%; the OS rate is 17.8%. All events occurred within 51 months of diagnosis. Four patients with distant metastases had progressive disease during therapy, and no patient with local-regional disease experienced disease progression during therapy. CONCLUSION Sustained EFS and OS can be achieved with intensive chemotherapy in children and young adults with local-regional EFTs. This therapy is relatively ineffective in the treatment of metastatic EFTs.

Irinotecan and temozolomide for Ewing sarcoma: The Memorial Sloan‐Kettering experience

The prognosis for recurrent/progressive Ewing sarcoma (ES) remains poor. Pre‐clinical, adult phase I and II trials have demonstrated the combination of irinotecan and temozolomide to have schedule‐dependent synergy and significant antitumor activity. A pediatric phase I trial has shown this regimen to be safe and active in advanced ES.

Treatment of osteosarcoma at first recurrence after contemporary therapy: the Memorial Sloan-Kettering Cancer Center experience.

Overall survival after recurrence of osteosarcoma (OS) is < 30%. The authors reported their experience treating recurrent OS at the time of first recurrence (R1).