Vaz MA, Valverde C, Alvarez R, Asencio JM, Collado E, de Alava E, Diaz R, Gómez MC, Gracia I, Marquina G, Martin J, Martínez J, Narváez JA, Redondo A, Sebio A, Verges R, Viñals JM, García Del Muro X. Diagnosis and Therapy of Soft Tissue Sarcomas: Spanish Group for Research in Sarcomas (GEIS) Guidelines