Sinonasal melanoma: Survival and prognostic implications based on site of involvement

Background: Sinonasal melanoma (SNM) is a rare malignancy that commonly presents at an advanced age and has a slight male predominance. Local recurrence has been implicated as a major reason for treatment failure, and there are poor reported 5-year survival rates. We analyzed the impact of specific location within the sinonasal region on the survival of this rare malignancy. Methods: The U.S. National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) registry was used to extract data on SNM between 1973 and 2009. Survival trends and hazard ratios (HRs) were calculated to compare the prognostic implications of involvement of varying areas of the sinonasal tract. Results: A total of 567 cases were identified. Females constituted 56.44% patient. Disease-specific survival (DSS) at 5 years was 36.66% for patients diagnosed with nasal cavity disease, 23.80% for patients with maxillary sinus tumors, and 18.20% for patients with ethmoid sinus disease. Patients showing evidence of overlapping sinus involvement had approximate 1-year survival of 54.45% and none survived beyond 49 months. HRs for maxillary sinus, ethmoid sinus, and overlapping sinus disease were 1.34, 1.60, and 2.30, respectively. All DSSs and HRs were statistically significant (p < 0.05). There was a higher proportion of earlier-stage disease in the nasal cavity compared to the most common paranasal sinus region (p < 0.05). Conclusion: Prognosis in SNM is dependent on the anatomic subsite. Paranasal sinus involvement indicates a poorer prognosis when compared to nasal cavity disease. Patients presenting with overlapping sinus involvement have the poorest prognosis.