GEIS-SEHOP clinical practice guidelines for the treatment of rhabdomyosarcoma.

Rhabdomyosarcoma (RMS) is the most frequent soft tissue sarcoma (STS) in children and adolescents. In Spain the annual incidence is 4.4 cases per million children < 14 years. It is an uncommon neoplasm in adults, but 40% of RMS are diagnosed in patients over 20 years of age, representing 1% of all STS in this age group. RMS can appear anywhere in the body, with some sites more frequently affected including head and neck, genitourinary system and limbs. Assessment of a patient with suspicion of RMS includes imaging studies (MRI, CT, PET-CT) and biopsy. All patients with RMS should receive chemotherapy, either at diagnosis in advanced or metastatic stages, or after initial resection in early local stages. Local control includes surgery and/or radiotherapy depending on site, stage, histology and response to chemotherapy. This guide provides recommendations for diagnosis, staging and treatment of this neoplasm.

Gastrointestinal stromal tumors (GISTs): SEAP-SEOM consensus on pathologic and molecular diagnosis.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the digestive tract, with an incidence of 1.1 cases/100,000 inhabitants/year. A group of experts from the Spanish Society of Pathology and the Spanish Society of Oncology met to discuss a brief update on GISTs and agree on aspects relating to the pathological and molecular diagnosis of these tumors. GISTs are generally solitary, well-circumscribed lesions of variable size (<10 mm-35 cm) that may present with intra- or extra-luminal parietal growth or a mixed-type (hourglass) growth pattern. Histologically, they are unencapsulated neoplasms displaying expansive growth and spindle-shaped (70%), epithelioid (20%), or mixed cellularity (10%). Mitotic activity is generally moderate or low and should be evaluated only in areas with high cellularity or higher mitotic frequency. The great majority of GISTs harbour mutually exclusive activating mutations in genes coding for the type III receptor tyrosine kinases KIT and PDGFRA; less commonly, GISTs have also been reported to display mutations elsewhere, including BRAF and NF1 and SDH-complex genes. The method most widely used to detect KIT and PDGFRA mutations is amplification of the exons involved by polymerase chain reaction followed by direct sequencing (Sanger method) of these amplification products. Molecular analyses should always specify the type of analysis performed, the region or mutations evaluated, and the sensitivity of the detection method employed.

SEOM Clinical Guideline of management of soft-tissue sarcoma (2016).

Soft-tissue sarcomas are uncommon and heterogeneous tumors of mesenchymal origin. A soft-tissue mass that is increasing in size, greater than 5 cm, or located under deep fascia are criteria for suspicion of sarcoma. Diagnosis, treatment, and management should preferably be performed by a multidisciplinary team in reference centers. MRI and lung CT scan are mandatory for local and distant assessment. A biopsy indicating histological type and grade is needed previous to the treatment. Wide surgical resection with tumor-free tissue margin is the primary treatment for localized disease. Radiotherapy is indicated in large, deep, high-grade tumors, or after marginal resection not likely of being improved with reexcision. Neoadjuvant and adjuvant chemotherapy improve survival in selected cases, usually in high-grade sarcomas of the extremities. In the case of metastatic disease, patients with exclusive lung metastasis could be considered for surgery. First-line treatment with anthracyclines (or in combination with ifosfamide) is the treatment of choice. New drugs have shown activity in second-line therapy and in specific histological subtypes.