Extent of parotid disease influences outcome in patients with metastatic cutaneous squamous cell carcinoma

Objectives: To test a new clinical staging system in patients with metastatic cutaneous squamous cell carcinoma involving the parotid gland or lymph nodes of the neck. Design: Retrospective analysis of clinicopathological data from patients with a minimum of 2 years' follow-up. Setting: Multidisciplinary head and neck unit in a tertiary referral center. Patients: Between 1987 and 1999,126 patients (104 men and 22 women; median age, 69 years) were treated for metastatic cutaneous squamous cell carcinoma involving the parotid and/or neck. Main Outcome Measures: Locoregional recurrence and disease-specific survival. Results; Of the 126 patients, disease involved the parotid gland in 81 patients, of whom 14 also had clinical neck disease, while 45 patients had neck involvement only. Parotid stages were as follows: PO, 45 patients; P1, 55; P2, 20; and P3, 6. Neck stages were: N0, 67 patients; N1, 31; and N2, 28. Treatment involved combined surgery and radiotherapy in 93 patients, surgery alone in 12, and radiotherapy alone in 18. Three patients received palliative treatment only. There were 47 therapeutic and 40 elective neck dissections. Pathologic evaluation demonstrated parotid involvement in 70 patients and neck involvement in 5 1, representing 44 therapeutic and 7 elective neck dissections. Disease involved both the parotid and neck in 19 patients. The 5-year local (parotid) control rate was 80% and this varied statistically significantly with P stage. Parotid stages 2 and 3 were independent risk factors for a decrease in local control rate using multivariate analysis. The 5-year disease-specific survival rate for the entire group was 68% and P stage significantly influenced survival: P0, 60%; P 1, 81%; P2, 51%; and P3, 33% (P<.001). Pathological involvement of neck nodes did not worsen survival of patients with parotid disease. Overall multivariate analysis demonstrated that single-modality therapy, P3 stage, and presence of immunosuppression independently predicted a decrease in survival. Conclusions: These results confirm that the extent of metastatic disease in the parotid gland significantly influences outcome and suggests that staging the parotid separately in metastatic cutaneous squamous cell carcinoma may be useful. Further evaluation of the recommended staging changes with a larger patient cohort will be required to clarify the influence of neck node involvement.