Current topics and management of head and neck sarcomas

Abstract

Given the low incidence, variety of histological types, and heterogeneous biological features of head and neck sarcomas, there is limited high-quality evidence available to head and neck oncologists. For resectable sarcomas, surgical resection followed by radiotherapy is the principle of local treatment, and perioperative chemotherapy is considered for chemotherapy-sensitive sarcomas. They often originate in anatomical border areas such as the skull base and mediastinum, and they require a multidisciplinary treatment approach considering functional and cosmetic impairment. Moreover, head and neck sarcomas may exhibit different behaviour and characteristics than sarcomas of other areas. In recent years, the molecular biological features of sarcomas have been used for the pathological diagnosis and development of novel agents. This review describes the historical background and recent topics that head and neck oncologists should know about this rare tumour from the following five perspectives: (i) epidemiology and general characteristics of head and neck sarcomas; (ii) changes in histopathological diagnosis in the genomic era; (iii) current standard treatment by histological type and clinical questions specific to head and neck; (iv) new drugs for advanced and metastatic soft tissue sarcomas; and (v) proton and carbon ion radiotherapy for head and neck sarcomas.

Keywords: Ewing’s sarcoma; angiosarcoma; chemotherapy; osteosarcoma; radiotherapy; rhabdomyosarcoma.

Figure 1

Pathological findings of alveolar rhabdomyosarcoma. (A) HE staining. Primitive, small, round cells appear to ‘float’ in a nest outlined by fibrous septa. (B) The nuclear expression of myogenin was 80%. (C) Desmin-positive cells are scattered. (D) The PAX3-FOXO1 fusion FISH probe. The fusion gene is detected as a yellow signal, with the green and red signals confocalized.

Figure 2

A case of alveolar rhabdomyosarcoma in a 6-year-old patient. (A–C) An invasive tumour located in the submandibular region. (D) After one cycle of VAC, the tumour dramatically shrunk. (E) After four cycles of VAC, the tumour was in complete remission on imaging. (F) Surgical specimen of a delayed primary excision (submandibular dissection). A few viable tumour cells were detected in the red lines. After DPE, VAC chemotherapy and postoperative radiotherapy were performed.

Figure 3

A 20-year-old woman with high-grade osteosarcoma of the mandible. (A) The tumour invaded to the masseter and pterygoid muscles. (B) Imaging results: after two cycles of MAP neoadjuvant chemotherapy. (C) Intraoperative photograph of segmental mandibulectomy. (D) Surgical specimen of segmental mandibulectomy. Viable tumour cells were detected in 70% of the area (red lines). After surgery, MAP chemotherapy and postoperative radiotherapy were performed.

Figure 4

A 32-year-old woman with Ewing’s sarcoma of the pharynx. (A) A submucosal tumour invading the anterior vertebral muscles was detected on the posterior wall of the pharynx. (B) After VDC-IE neoadjuvant chemotherapy, the tumour was in complete remission on imaging. (C) Partial pharyngectomy and free flap reconstruction were performed. The resected specimen revealed no viable tumour cells. After surgery, VDC-IE chemotherapy was performed.