Soft Tissue Metastases in Head and Neck Cutaneous Squamous Cell Carcinoma

Soft tissue metastases (STM) in head and neck cutaneous squamous cell carcinoma (HNcSCC) are non-nodal based metastases to the parotid and cervical soft tissues of the head and neck. This is a unique subgroup of regional metastases amongst patients with cSCC and have been shown to be associated with poor prognosis. Detailed studies of this subgroup are lacking in the literature. A retrospective cohort analysis was performed to characterize the prognostic significance of STM in HNcSCC based on individual clinicopathological features.

Patients with HNcSCC with STM were identified from the Sydney Head and Neck Cancer Institute database. Clinicopathological characteristics were extracted from the histopathological reports. Recurrence and follow-up data were analyzed to determine disease-free and overall survival using the Kaplan-Meier method and Cox proportional hazards models.

After excluding all patients with lymph node metastasis with no STM, there were 200 patients identified (161 parotid, 32 cervical, and seven with concurrent parotid and cervical STM) with a 5-year overall survival of 36%. In univariable analysis, age of patients, size of the deposits, location of the deposits, and patients that were not offered adjuvant radiotherapy have worse overall survival. However, on multivariable analysis, age and the number of STM deposits were independent factors that predict for worse survival.

The presence of STM in patients with HNcSCC is associated with poor prognosis. Increasing number of STM deposits, as well as involved margin of the regional excision, negatively impacted on the overall prognosis.

Level III - retrospective cohort study. Laryngoscope, 131:E1209-E1213, 2021.