Abstract
IMPORTANCE: There are significant gaps in the literature pertaining to the locoregional control and survival rates of extramedullary plasmacytoma (EMP) with respect to various treatment approaches. OBJECTIVE: To systematically evaluate the differences in radiotherapy and surgical outcomes in EMP. DATA SOURCES: Databases including PubMed, Scopus, Web of Science, Embase, and ScienceDirect were systematically searched from their inception up to November 2023. STUDY SELECTION: Articles reporting radiotherapy and surgical outcomes of head and neck EMP were included. DATA EXTRACTION AND SYNTHESIS: A random-effects model for meta-analysis was used to obtain pooled estimates and calculate hazard ratios for survival and odds ratios for recurrence and progression of EMP. MAIN OUTCOMES AND MEASURES: Survival, tumor control, and progression rates to multiple myeloma (MM) between radiation therapy and surgery for EMP of the head and neck. RESULTS: Of 742 included patients from 12 studies, 527 (71.0%) were male, and the median (IQR) age was 59.1 (53-62) years. A total of 505 patients (68.1%) received radiotherapy only, while 237 (31.9%) underwent surgery-only treatment for EMP. All included patients had an initial diagnosis of EMP without MM. Comparable trends were observed in overall survival and disease-free survival (DFS) rates at 2, 3, 5, and 10 years between patients with EMP treated with radiotherapy only and surgery only. Notably, there were no significant differences in recurrence rate (odds ratio, 0.65; 95% CI, 0.20-2.06) between radiotherapy-only and surgery-only treatment. However, radiotherapy-only treatment of EMP was associated with decreased odds of progression to MM compared with surgery (odds ratio, 0.4; 95% CI, 0.1-0.9). Sensitivity analysis revealed that the radiotherapy-only population had significantly better 5-year DFS (hazard ratio, 0.55; 95% CI, 0.31-0.96) compared with surgery-only treatment. CONCLUSIONS AND RELEVANCE: This systematic review and meta-analysis provides evidence that patients with EMP receiving radiotherapy had significantly lower chances of progression to MM compared with surgery-only therapy. Additionally, radiotherapy had better 5-year DFS outcomes compared with surgery. Comparable outcomes in terms of overall survival rates, recurrence, and mortality rates were noted between radiotherapy-only and surgery-only EMP treatment groups.