Desmoplastic Melanoma of the Head and Neck: Incidence and Survival, 1992-2013.

Objective To describe the epidemiological characteristics and survival of desmoplastic melanoma of the head and neck (DMHN) and discuss the factors influencing survival variation among DMHN, DM of other sites (DMnHN), and conventional melanoma of the head and neck (CMHN). Study Design Retrospective cohort study. Setting Surveillance, Epidemiology, and End Results (SEER) database (years 1992-2013). Subjects and Methods Incidence and survival data for 1095 patients with DMHN, 1139 patients with DMnHN, and 40,257 patients with CMHN were obtained. Kaplan-Meier and Cox proportional hazards regression models were used to calculate survival outcomes. Results Patients with DMHN were diagnosed at greater Breslow thickness ( P < .001), stage ( P < .001), and Clark's level ( P < .001) compared to DMnHN and CMHN. Kaplan-Meier survival analysis demonstrated disease-specific survival (DSS) at 5 and 10 years for DMHN to be 80.5% and 74.7%, respectively, compared with 89.1% and 86%, respectively, for DMnHN and 88.1% and 83%, respectively, for CMHN (log-rank test; P < .001). On multivariate Cox regression analysis, age at diagnosis ( P < .001), Breslow depth >4.00 mm ( P = .006), lymph node status ( P < .001), and presence of ulceration ( P < .001) were found to be independent predictors of DSS for DMHN. Conclusion The increasing incidence and poor survivability of DMHN compared to DMnHN and CMHN are parsimoniously explained by the later stage of disease and depth of invasion at diagnosis, highlighting the importance of improved diagnosis and awareness of DMHN.