Metastatic Cutaneous Squamous Cell Carcinoma to the Axilla: A Review of Patient Outcomes and Implications for Future Practice

BACKGROUND: Nodal metastasis from cutaneous SCC carries a high morbidity and mortality. Limited direct evidence is available as to the impact of radiotherapy on the outcome of patients with metastatic axillary SCC. The purpose of this study was to report on the outcomes of patients with metastatic cutaneous SCC to the axilla treated with radiotherapy. METHODS: A retrospective review of patients treated with radiotherapy between 1993 and 2010 for metastatic cutaneous SCC to the axilla was undertaken at St George Hospital, Sydney. RESULTS: Radiotherapy was administered to 36 patients, 30 with curative intent (4 definitive, 26 adjuvant) and 6 with palliative intent, 27/36 (75%) were male, 22/36 (61%) had a previous diagnosis of cutaneous SCC, and 1/36 (3%) was immunosuppressed. Mean age was 74.6 years. Mean radiotherapy dose (BEDGy10) was 61Gy(10) (range 39-85 Gy(10)), 20/36 (56%) patients experienced recurrence, including 16 local failures and 4 isolated distant failures. Median survival for the curative and palliative groups was 3 years and 1 month, respectively. Relapse free survival (n = 36) at 2 and 5 years was 46% and 35%, respectively (curative 52% and 39%). Only 1 failure achieved complete salvage. CONCLUSION: Despite current best practice (surgery and radiotherapy), the predominant pattern of failure in these patients with metastatic axillary cSCC was locoregional. The difficulty in successfully salvaging patients after locoregional nodal relapse suggests a need for treatment intensification.