PTPN11 mutations in canine and human disseminated histiocytic sarcoma.

In humans, histiocytic sarcoma (HS) is an aggressive cancer involving histiocytes. Its rarity and heterogeneity explain that treatment remains a challenge. Sharing high clinical and histopathological similarities with human HS, the canine HS is conversely frequent in specific breeds and thus constitutes a unique spontaneous model for human HS to decipher the genetic bases and to explore therapeutic options. We identified sequence alterations in the MAPK pathway in at least 63.9% (71/111) of HS cases with mutually exclusive BRAF (0.9%; 1/111), KRAS (7.2%; 8/111) and PTPN11 (56.75%; 63/111) mutations concentrated at hotspots common to human cancers. Recurrent PTPN11 mutations are associated to visceral disseminated HS subtype in dogs, the most aggressive clinical presentation. We then identified PTPN11 mutations in 3/19 (15.7%) human HS patients. Thus, we propose PTPN11 mutations as key events for a specific subset of human and canine HS: the visceral disseminated form. Finally, by testing drugs targeting the MAPK pathway in eight canine HS cell lines, we identified a better anti-proliferation activity of MEK inhibitors than PTPN11 inhibitors in canine HS neoplastic cells. In combination, these results illustrate the relevance of naturally affected dogs in deciphering genetic mechanisms and selecting efficient targeted therapies for such rare and aggressive cancers in humans.

Activity of Pazopanib and Trabectedin in Advanced Alveolar Soft Part Sarcoma.

BACKGROUND: Alveolar soft part sarcoma (ASPS) is an exceedingly rare and orphan disease, without active drugs approved in the front line. Pazopanib and trabectedin are licensed for sarcoma treatment from second-line, but very little and contradictory data are available on their activity in ASPS. Lacking ongoing and/or planned clinical trials, we conducted a multi-institutional study involving the reference sites for sarcoma in Europe, U.S., and Japan, within the World Sarcoma Network, to investigate the efficacy of pazopanib and trabectedin. MATERIALS AND METHODS: From May 2007, 14 of the 27 centers that were asked to retrospectively review their databases had identified 44 advanced ASPS patients treated with pazopanib and/or trabectedin. Response was evaluated by Response Evaluation Criteria in Solid Tumors 1.1. Progression-free survival (PFS) and overall survival (OS) were computed by Kaplan-Meier method. RESULTS: Among 30 patients who received pazopanib, 18 were pretreated (13 with other antiangiogenics). Response was evaluable in 29/30 patients. Best responses were 1 complete response, 7 partial response (PR), 17 stable disease (SD), and 4 progressions. At a 19-month median follow-up, median PFS was 13.6 months (range: 1.6-32.2+), with 59% of patients progression-free at 1 year. Median OS was not reached.Among 23 patients treated with trabectedin, all were pretreated and evaluable for response. Best responses were 1 PR, 13 SD, and 9 progressions. At a 27-month median follow-up, median PFS was 3.7 months (range: 0.7-109), with 13% of patients progression-free at 1 year. Median OS was 9.1 months. CONCLUSION: The value of pazopanib in advanced ASPS is confirmed, with durable responses, whereas the value of trabectedin appears limited. These results are relevant to defining the best approach to advanced ASPS. IMPLICATIONS FOR PRACTICE: This retrospective study, conducted among the world reference centers for treatment of sarcoma, confirms the value of pazopanib in patients with advanced alveolar soft part sarcoma (ASPS), with dimensional and durable responses, whereas trabectedin shows a limited activity. Alveolar soft part sarcoma is resistant to conventional cytotoxic chemotherapy. Pazopanib and trabectedin are licensed for treatment of sarcoma from second line; in the lack of prospective clinical trials, these results are relevant to defining ASPS best management and strongly support initiatives aimed at obtaining the approval of pazopanib in the front line of the disease.

Sorafenib in patients with progressive epithelioid hemangioendothelioma: a phase 2 study by the French Sarcoma Group (GSF/GETO).

BACKGROUND: There is no standard treatment for progressive epithelioid hemangioendothelioma (EHE). To investigate the significant vascularization of EHE, the activity/toxicity of sorafenib in patients with progressive EHE was explored. METHODS: In this multicenter, 1-stage, phase 2 trial of sorafenib (800 mg daily), the primary endpoint, which was chosen by default, was the 9-month progression-free rate. All patients had documented progressive disease at the time of study entry. RESULTS: Fifteen patients were enrolled between June 2009 and February 2011. The median age was 57 years (range, 31-76 years), and the ratio of men to women was 9:6. The performance status was zero in 10 patients and 1 in 5 patients. Twelve patients had metastases, mainly in the lung (12 patients), liver (5 patients), and bone (3 patients). Five patients had received prior chemotherapy (doxorubicin in 5 patients and taxane in 3 patients). The median sorafenib treatment duration was 124 days (range, from 27 to >271 days). Seven patients required dose reductions or transient treatment discontinuation. The 9-month progression-free rate was 30.7% (4 of 13 patients). The 2-month, 4-month, and 6-month progression-free rate was 84.6% (11 of 13 patients), 46.4% (6 of 13 patients), and 38.4% (5 of 13 patients), respectively. Two partial responses were observed that lasted 2 months and 9 months. CONCLUSIONS: Further clinical trials exploring sorafenib as treatment of progressive EHE are needed.

The 100 Most Influential Papers and Recent Trends in the Field of Gastrointestinal Stromal Tumours: A Bibliometric Analysis.

Background Bibliometric analysis is a statistical tool used to examine the exponential growth in medical research. Many analogous analyses have been conducted, but none existed for gastrointestinal stromal tumors (GISTs). Hence, we conducted a citation analysis of the hundred most cited and recently published articles on this topic. Methods Scopus was chosen as the primary database, through which the top 100 and recent publications were ranked according to the citation count and were then analysed. Results The 100 most cited articles were published between 1992 and 2013, among which the greatest number of articles were published in the years 2002 (n = 15) and 2006 (n = 11). Amidst the 24 countries from which the articles originated, the United States of America (n = 76) topped the list. The Journal of Clinical Oncology (n = 15) and the American Journal of Clinical Pathology (n = 10) contributed majority of the top articles. Harvard Medical School alone produced 44 of the top 100. Articles from 2013 to date showed the same trend as that of top 100 articles regarding origin and institutions. Conclusion Basic science and genetics of GISTs are established, and new drugs are being studied for medicinal therapy. Surgical management and diagnostics of these tumors, however, are yet to be studied as extensively.

Response to imatinib in villonodular pigmented synovitis (PVNS) resistant to nilotinib.

BACKGROUND: Pigmented villonodular synovitis (PVNS) is a rare locally aggressive tumor. PVNS is characterized in most cases by a specific t(1;2) translocation, which fuses the colony stimulating factor-1 (CSF1) gene to the collagen type VIa3 (COL6A3) promoter thus leading through a paracrine effect to the attraction of non-neoplastic inflammatory cells expressing CSF1-receptor. Imatinib is a tirosin-kinase inhibitors (TKI) active against CSF1-receptor whose activity in naïve PVNS was already described. We report on two PVNS patients who responded to imatinib after failure to nilotinib, another CSF1-receptor inhibitor. METHODS: Since August 2012, 2 patients with progressive, locally advanced PVNS resistant to nilotinib (Patient 1: man, 34 years; Patient 2: woman, 24 years) have been treated with second-line imatinib 400 mg/day. Both patients are evaluable for response. RESULTS: Both patients are still on treatment (7 and 4 months). Patient 1 had a dimensional response by MRI after 2 months from starting imatinib, together with symptomatic improvement. In Patient 2 a metabolic response was detected by [18F]fluorodeoxyglucose-positron emission tomography (PET) at 6 weeks coupled with tumor shrinkage by MRI, and symptomatic improvement. CONCLUSIONS: Imatinib showed antitumor activity in 2 patients with nilotinib-resistant PVNS. This observation strengthen the idea that targeted agent with similar profile can give a different clinical result, as already described for gastrointestinal stromal tumor (GIST) patients treated with the same agents. Molecular studies are needed to clarify the biologic mechanism(s) underlying the response.

Efficacy and safety of trabectedin in patients with advanced or metastatic liposarcoma or leiomyosarcoma after failure of prior anthracyclines and ifosfamide: results of a randomized phase II study of two different schedules.

PURPOSE: To evaluate the safety and efficacy of trabectedin in a phase II, open-label, multicenter, randomized study in adult patients with unresectable/metastatic liposarcoma or leiomyosarcoma after failure of prior conventional chemotherapy including anthracyclines and ifosfamide. PATIENTS AND METHODS: Patients were randomly assigned to one of two trabectedin regimens (via central venous access): 1.5 mg/m(2) 24-hour intravenous infusion once every 3 weeks (q3 weeks 24-hour) versus 0.58 mg/m(2) 3-hour IV infusion every week for 3 weeks of a 4-week cycle (qwk 3-hour). Time to progression (TTP) was the primary efficacy end point, based on confirmed independent review of images. RESULTS: Two hundred seventy patients were randomly assigned; 136 (q3 weeks 24-hour) versus 134 (qwk 3-hour). Median TTP was 3.7 months versus 2.3 months (hazard ratio [HR], 0.734; 95% CI, 0.554 to 0.974; P = .0302), favoring the q3 weeks 24-hour arm. Median progression-free survival was 3.3 months versus 2.3 months (HR, 0.755; 95% CI, 0.574 to 0.992; P = .0418). Median overall survival (n = 235 events) was 13.9 months versus 11.8 months (HR, 0.843; 95% CI, 0.653 to 1.090; P = .1920). Although somewhat more neutropenia, elevations in AST/ALT, emesis, and fatigue occurred in the q3 weeks 24-hour, this regimen was reasonably well tolerated. Febrile neutropenia was rare (0.8%). No cumulative toxicities were noted. CONCLUSION: Prior studies showed clinical benefit with trabectedin in patients with sarcomas after failure of standard chemotherapy. This trial documents superior disease control with the q3 weeks 24-hour trabectedin regimen in liposarcomas and leiomyosarcomas, although the qwk 3-hour regimen also demonstrated activity relative to historical comparisons. Trabectedin may now be considered an important new option to control advanced sarcomas in patients after failure of available standard-of-care therapies.