Sarcomas of the Head and Neck

Overview
Overall, sarcomas are particularly rare neoplasms as they constitute only 1% of all cancer diagnosed in the United States and 1% of all head and neck primary cancers. Furthermore, these tumors do not commonly manifest as primary malignancies in the head and neck region except in the pediatric population, in which as many as 35% of all sarcomas affect head and neck sites. The most commonly encountered sarcomas of the head and neck region are osteogenic sarcoma, malignant fibrous histiocytoma, rhabdomyosarcoma, and angiosarcoma.

The rarity of sarcomas, as well as the multitude of histologic subtypes, can make definitive diagnosis difficult, and an experienced pathologist is key to the initial evaluation. Appropriate pathologic characterization forms the basis for prognosis and subsequent treatment selection. The biology of a neoplasm and its propensity for locally aggressive growth and systemic dissemination are clearly reflected in its histology and grade. Size and location of the lesion, which have become more precisely delineated with improvements in radiographic modalities, also impart reliable prognostic information. All of these factors, along with the complexities of head and neck anatomy (especially regarding function and cosmesis), make optimal treatment difficult to determine in many cases.

Traditionally, surgery has formed the cornerstone of therapy for head and neck sarcomas. However, multimodality treatment of these tumors incorporating a multidisciplinary approach has yielded encouraging results. Data collected by ongoing cooperative studies such as the Intergroup Rhabdomyosarcoma Study Group (IRSG) have demonstrated improved outcomes for those patients treated with surgery along with other nonsurgical modalities. These protocols also serve as a model for the evolving roles of chemotherapy and radiation either as adjuvant treatments or even primary therapy in select patients. As a result, many patients, particularly children, are now able to avoid surgery in functionally and cosmetically critical areas of the head and neck without compromising their survival.

Osteosarcoma
Osteogenic sarcoma is the most common nonhematopoietic malignant neoplasm of bone, usually occurring in the long bones of adolescent patients. However, 10% of these neoplasms arise in the head and neck region and occur in patients who are on average 10 to 15 years older than those patients with tumors occurring in other body sites. Most of these tumors present as a painless mass of the maxilla or mandible, often accompanied by loose teeth. Surgical resection achieving negative margins remains the crucial element in the treatment of head and neck osteosarcomas. It has been repeatedly shown that surgical margin status correlates significantly with local control and survival. In those cases in which margins were positive following resection, 5-year survival decreased dramatically to 35% from approximately 75% in those individuals with negative margins. In one series, positive margins were shown to be uniformly fatal at 4 years after treatment. Most recent experiences with this disease have been with multimodality therapy. Several centers have applied external beam irradiation in the postoperative period, particularly in cases of high-grade tumors, large lesions, close or positive margins, or inoperability. Unfortunately, radiation, whether delivered externally or as brachytherapy, does not appear to significantly improve overall survival in head and neck osteosarcomas. The addition of chemotherapy, however, has shown greater promise as an adjuvant modality in the treatment of osteosarcomas, especially in those individuals with lesions of the extremities. In a meta-analysis of 201 patients with craniofacial osteosarcomas, Smeele and colleagues suggested that chemotherapy increases survival even in those cases of incomplete surgical resection. Nevertheless, other series and meta-analyses have not shown such promising results. Five-year survival in larger series is only 42% to 55%, and disease-free survival at 5 years is achieved in only 25% to 30% of all patients. Combinations of surgery and chemotherapy, and possibly even radiation, for these aggressive neoplasms may provide better outcomes. Data continue to accrue, and future treatment protocols will be instituted based on these experiences.