Metastatic cutaneous squamous cell carcinoma to the parotid: the role of surgery and adjuvant radiotherapy to achieve best outcome.

BACKGROUND: Australia has the highest incidence of cutaneous squamous cell carcinoma in the world. The majority of lesions occur in the head and neck with metastases to the parotid gland lymph nodes reflecting an uncommon, but aggressive, manifestation. Parotidectomy +/- neck dissection followed by adjuvant radiotherapy should be considered as best practice.

METHODS: Between 1983 and 2000, seventy-four patients were treated for metastatic cutaneous squamous cell carcinoma to the parotid with surgery and adjuvant radiotherapy at Westmead Hospital, Sydney. Relevant data were extracted from patient files and a prospectively maintained database. Patterns of relapse and outcome were analysed.

RESULTS: Median age at diagnosis was 65 years (34-93 years) in 63 men and 11 women. Median follow-up duration was 41 months (12-188 months). All patients underwent parotidectomy with 52 undergoing a simultaneous neck dissection. Twelve patients required sacrifice of the facial nerve (4) or one or more branches (8). All received adjuvant radiotherapy to the parotid region with 56 also receiving radiotherapy to the ipsilateral neck. Despite treatment, 24% developed locoregional recurrence, with a median time to relapse of 7.5 months. The most common site for recurrence was the treated parotid region and upper neck. Most relapsed patients died. No variable independently predicted for locoregional recurrence on multivariate analysis. The 5-year absolute and cause-specific survival rates were 58% and 72%, respectively.

CONCLUSION: Parotid gland lymph node metastases from cutaneous squamous cell carcinoma are associated with a high rate of recurrence and cause-specific mortality despite current best practice (surgery and high dose adjuvant radiotherapy). The role of more aggressive surgery, altered fractionation or chemotherapy to enhance locoregional control remains unclear.