Sinonasal extramedullary plasmacytoma: a population-based incidence and survival analysis

Sinonasal extramedullary plasmacytoma (SN-EMP) is a rare plasma cell neoplasm. Published literature on this tumor largely consists of case reports and case-series with small sample sizes. This study analyzed population-based data on SN-EMP patients to understand demographic and clinical features as well as incidence and survival trends.

The Surveillance, Epidemiology, and End Results (SEER) database was queried for SN-EMP and other head and neck EMP (HN-EMP) cases from 1973 to 2011. Cases were analyzed to determine patient demographics, initial treatment modality, and survival outcomes.

Of 778 patients identified with EMP in the head and neck region, 367 patients had SN-EMP and 411 had other HN-EMP. There was a strong male predilection found, with a male-to-female ratio of 3.65:1 in the SN-EMP group and 1.87:1 in the other HN-EMP group. The majority of the patients presented with localized disease in both SN-EMP (84.4%) and other HN-EMP (81.0%) groups. The most common treatment modality reported in this database was surgery with adjuvant radiotherapy in both SN-EMP (46.3%) and other HN-EMP (38.9%) groups, followed by radiotherapy alone (SN-EMP: 40.7%; other HN-EMP: 34.2%). Five-year and 10-year disease-specific survival rates were comparable between SN-EMP (88.2% and 83.3%, respectively) and other HN-EMP (90.0% and 87.4%, respectively) (p = 0.6016 and p = 0.4015, respectively).

This study analyzed the largest cohort of SN-EMP patients to date. There was no statistically significant survival advantage found for any 1 particular treatment modality over other treatment modalities in both SN-EMP and other HN-EMP.