Soft tissue sarcomas (STSs) are rare malignant tumors, of which 3/4 are high-grade and 1/3 metastasize. For optimal management, STSs should be treated at multidisciplinary sarcoma centers. Study I demonstrated that simple referral guidelines, an open-access outpatient clinic and repeated educative measures to raise sarcoma awareness result in successful referral of untouched STSs to sarcoma center. Further, for each malignant tumor, 3 benign tumors were referred. Study II showed that though small STSs in general have a good prognosis, tumors with either of the risk factors necrosis or intratumoral vascular invasion had a 3-fold increased risk and STSs with both risk factors had an 11-fold increased risk of metastases. Study III describes changing clinical presentation of secondary angiosarcoma after breast cancer treatment; from late tumors in edematous arms, after median 11 years, to early tumors in the irradiated fields after median 7 years. Study IV report that secondary angiosarcomas on the thoracic wall are difficult to treat; the recurrence rate is high also after surgery with R0 margins and the prognosis dismal. Study V addressed differences in gene expression profiles between primary and secondary angiosarcomas. In secondary angiosarcomas RET, KIT and FLT4 within the receptor protein tyrosine kinase pathway, are significantly up-regulated. In summary, these studies show that high referral rates of STSs to a sarcoma center are possible to achieve, that small STSs with necrosis and vascular invasion had high risk of metastases, that the clinical presentation of secondary angiosarcomas has changed, that these tumors have high recurrence rates, and that up-regulation of the receptor protein tyrosine kinase pathway is common
