[30] Advantages of a National Pathological Network for a Systematic Second Review in Sarcomas: Experience of a One-Year Activity in France

Jean Michel Coindre, Dominique Ranchere-Vince, Philippe Terrier, Jean Francois Emile, Bruno Chetaille, Sophie Le Guellec, Yves Marie Robin, Francois Collin, Anne Valerie Decouvelaere, Agnes Neuville. Bergonié, Bordeaux, France; Centre Léon Bérard, Lyon, France; Institut Gustave Roussy, Villejuif, France; APHP, Paris, France; Institut Paoli Calmettes, Marseille, France; Institut Claudius Regaud, Toulouse, France; Centre Oscar Lambret, Lille, France; Centre Georges-François Leclerc, Dijon, France

Background: Previous systematic histologic reviews have shown high rate of discordances in sarcomas. Therefore, in 2009 the French Institut National du Cancer (INCa) accredited a network of pathologists to organize a systematic second review of sarcomas.
Design: The network comprises 3 coordinating centers (CC) and 19 referent centers (RC). Every new sarcoma, GIST or desmoid tumor should be referred to one of these centers for a second review. A molecular test should be used for every suspicion of translocation, MDM2 amplification or specific mutation. This second review is sufficient for GIST with KIT and DOG1 positivity, Kaposi sarcoma with HHV8 positivity, sarcomas with a proved specific translocation, atypical lipomatous tumor-well differentiated liposarcoma (ALT-WDLPS) or dedifferentiated LPS (DDLPS) with a MDM2 amplification and desmoid tumors with a CTNNB1 mutation. Other cases even reviewed by a RC are referred to a CC for a third review. The discordant cases are collegially reviewed every month around a multi-head microscope. A set of 30 parameters is collected for every case and registered in a shared database (www.rreps.org).
Results: In 2010, 3653 tumors have been registered with 2357 cases referred from pathologists outside of the network (65%): 1500 cases were spontaneously sent for a second opinion (SO) and 857 were sent for a systematic review according to the recommendations of INCa (SR). The most frequent histotypes were LPS (593 with 226 ALT-WDLPS and 219 DDLPS), undifferentiated pleomorphic sarcomas (532), GIST (508), leiomyosarcomas (368), dermatofibrosarcoma protuberans (184) and desmoid tumors (179). A major discordance has been observed in 25.3% of SO and in 8.1% of SR cases with 220 benign lesions mistaken for a sarcoma, GIST or desmoid tumor (49% of discordances). FISH analysis has been used in 1102 cases with a positive result in 63% and other molecular tests in 961 cases with a positive result in 67%. Frozen tissue has been stored for 885 tumors (24%).
Conclusions: This study confirms the need for a systematic review for sarcomas, GISTs or desmoid tumors. A network organisation improves homogeneity of practice in terms of diagnostic criteria and use of ancillary techniques; knowledge on these rare tumors, and amount and quality of data and material for research purposes.
Category: Bone & Soft Tissue

Monday, March 19, 2012 1:00 PM

Poster Session II # 37, Monday Afternoon


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