Epidemiologic evidence of superior outcomes for extramedullary plasmacytoma of the head and neck.

Abstract

To compare clinicopathologic data, epidemiologic factors, and survival outcomes between extramedullary plasmacytomas of the head and neck vs other body sites. Analysis of a national database. Extramedullary plasmacytoma (EMP) is a rare B-cell neoplasm with a tendency to occur in the head and neck. Due to limited clinical data, few studies have conducted a thorough comparison between head and neck EMPs and those arising at other body sites. We compared 690 EMPs of the head and neck with 495 non-head and neck EMPs, evaluating disease-specific survival (DSS) and overall survival (OS) based on tumor type, location, grade, stage, and treatment. Head and neck EMPs more often affected men (P > .001) and were typically located in the pharynx (21.5%), nasal cavity (19.3%), oral cavity (14.7%), and paranasal sinuses (13.0%). Non-head and neck EMPs were more often limited to only local disease at presentation (94.8% vs 82.1%-86.7%, P < .001). Patients with non-head and neck EMP more often received surgery alone, whereas those with head and neck EMP were more often treated with combination therapy or radiation alone (P < .001). Head and neck EMPs had a significantly higher 5-year DSS and OS than other plasmacytomas (P < .001), and they had a higher 10-year OS when treated with surgery or combination therapy than with radiation alone (P = .003). Extramedullary plasmacytoma of the head and neck represents a type of tumor unique from other plasmacytomas, with distinct epidemiologic characteristics and a superior prognosis. Evidence suggests that surgically based treatments may offer improved outcomes.