Staging cutaneous squamous cell carcinoma metastases to the parotid gland.

Objective: The staging of cutaneous squamous cell cancers (cSCC) was revised by the American Joint Committee on Cancer in 2010 to incorporate known prognostic factors and expand the N (node) category. The purpose of this study was to validate this staging system using a North American cohort, and to compare it to the O'Brien P (Parotid) and N staging system.

Methods: An exhaustive collaborative database search was performed for all patients with cSCC metastasis to the parotid gland treated at three major Canadian tertiary referral centers from December 1999 to March 2015. The data collected for each patient included overall survival; disease-free survival; tumor, node, and metastasis) staging; and postoperative radiation status. Post-hoc analysis was completed to discern the strongest prognostic factors of survival as they relate to the abovementioned staging systems.

Results: Of 136 patients identified, 80% had a documented history of previously treated head and neck cSCC an average of 27 months prior to presentation. Average size of the parotid lesion at recurrence was 4.5 cm. Ninety-six percent of patients underwent surgical resection of the parotid metastasis. Five-year overall and disease-free survival is 79% and 55%, respectively. Only cSCC staging and cSCC-N category had statistically significant differences between groups. cSCC staging had the largest percentage of variation in overall survival explained.

Conclusion: Patients with cSCC metastasis to the parotid gland proved to have a moderate survival rate, despite presenting with advanced disease. cSCC staging in the setting of parotid metastasis, despite its limitations, currently offers the most predictive staging system available.

Level Of Evidence: 4. Laryngoscope, 127:2063-2069, 2017.