Head & Neck Spindle Cell Melanoma

Purpose: Head Neck Spindle Cell Melanoma (HNSCM) is very rare morphologic subtype of melanoma and unexplored comprehensively. The aim of this study was to investigate HNSCM’s incidence, general demographics, basic clinico-pathologic features, and treatment outcome and disease specific prognostic factors. Material and Methods: HNSCM cases were identified in Surveillance, Epidemiology, and End Results database (1973-2018). Results: A total of 2500 HNSCM cases with a median age of 66 years were found in the database. The Male-to-female ratio is 2:1. Statistically significant Overall Survival (OS) and Disease Specific Survival (DSS) differences were found were depending on age, gender, race, age, tumor location, SEER historic stage, T stage, N stage, M stage and pathological differentiation (p<0.05). In the multivariate Cox regression analysis, age >66 years [Hazard ratio (HR) (95%, Confidence Interval, CI) =2.785 (2.224-3.488), p=0.000, for OS; HR (95% CI) =2.140 (1.535-2.983), p=0.000, for DSS, age ≤ 66 years as reference], unmarried status [HR (95% CI) =1.254 (1.031-1.525), p=0.023, for OS, married as reference], T3+T4 stage [HR (95% CI) =1.330 (1.080-1.639), p=0.007, for OS, HR (95% CI) =1.577 (1.106-2.247), p=0.012, for DSS, TX+T1+T2, as reference] and M1 stage [HR (95% CI) =2.658 (1.385-5.101), p=0.003, for OS, HR (95% CI) =6.894 (2.122-22.39), p=0.003, for DSS, M0 as reference] were associated with worse DSS and OS. Besides, the non-skin tumor [HR (95% CI) =0.511 (0.366-0.714), p=0.000, for OS, HR (95% CI) =0.603 (0.366-0.994), for DSS, p=0.047 skin tumor as reference] was associated with favorable DSS. Conclusion: HNSCM mostly occurred in white people at 60~80 years old with predominance in males. The patient’s age, tumor location, T stage, M stage and marital status were independent prognostic factors for DSS and OS.