Key roles for MYC, KIT and RET signaling in secondary angiosarcomas.

BACKGROUND: Angiosarcomas may develop as primary tumours of unknown cause or as secondary tumours, most commonly following radiotherapy to the involved field. The different causative agents may be linked to alternate tumorigenesis, which led us to investigate the genetic profiles of morphologically indistinguishable primary and secondary angiosarcomas. METHODS: Whole-genome (18k) c-DNA-mediated annealing, selection, extension and ligation analysis was used to genetically profile 26 primary and 29 secondary angiosarcomas. Key findings were thereafter validated using RT-qPCR, immunohistochemistry and validation of the gene signature to an external data set. RESULTS: In total, 103 genes were significantly deregulated between primary and secondary angiosarcomas. Secondary angiosarcomas showed upregulation of MYC, KIT and RET and downregulation of CDKN2C. Functional annotation analysis identified multiple target genes in the receptor protein tyrosine kinase pathway. The results were validated using RT-qPCR and immunohistochemistry. Further, the gene signature was applied to an external data set and, herein, distinguished primary from secondary angiosarcomas. CONCLUSIONS: Upregulation of MYC, KIT and RET and downregulation of CDKN2C characterise secondary angiosarcoma, which implies possibilities for diagnostic application and a mechanistic basis for therapeutic evaluation of RET-kinase-inhibitors in these highly aggressive tumours.

Simple guidelines for efficient referral of soft-tissue sarcomas: a population-based evaluation of adherence to guidelines and referral patterns.

BACKGROUND: Optimal treatment of soft-tissue sarcoma requires multidisciplinary management at a sarcoma center. However, these rare tumors are often misinterpreted as benign and many are inadequately treated outside a sarcoma center, with an increased risk of local recurrence that often requires further extensive surgical treatment. To improve referral and centralization of soft-tissue sarcoma management in the southern Sweden health care region, an open-access outpatient clinic at our sarcoma center and simple referral guidelines have been established for the past thirty years. The guidelines call for referral of all deep-seated soft-tissue tumors and of all ≥5-cm superficial tumors before open biopsy or surgery. We evaluated adherence to these guidelines and characterized referral patterns. We also studied the consequences of our strategy with regard to the relative numbers of benign and malignant diagnoses among referred patients. METHODS: Adherence to guidelines, referral pathways, and time to referral to the sarcoma center were analyzed in a population-based series of 100 consecutive patients with soft-tissue sarcoma in the extremities or trunk wall. We also analyzed diagnosis and management of benign and malignant tumors in a second cohort consisting of 464 consecutive patients referred to the sarcoma center because of a soft-tissue tumor. RESULTS: Ninety-seven of the 100 patients with soft-tissue sarcoma were referred to the sarcoma center. All fifty-eight of the deep-seated soft-tissue sarcomas and twenty-eight of the forty-two superficial tumors were referred before open biopsy or surgery. Three-quarters of the patients with soft-tissue sarcoma first presented to a general practitioner. One-quarter of these patients were directly referred to the sarcoma center, which cut the referral time in half compared with patients initially referred to a local hospital. One-quarter of all patients referred to the outpatient clinic were diagnosed with a malignancy, with the majority of the malignancies being soft-tissue sarcoma. CONCLUSIONS: Our simple referral guidelines and open-access outpatient clinic resulted in nearly complete referral of patients with soft-tissue sarcoma to the sarcoma center. The "excess work" associated with referral of benign tumors according to our strategy was limited to the diagnosis of three benign tumors for each malignant tumor. We consider this surplus evaluation of benign tumors acceptable and probably necessary to achieve a high referral rate of soft-tissue sarcoma before initial surgery. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.