Merkel cell carcinoma: An Australian perspective and the importance of addressing the regional lymph nodes in clinically node-negative patients

Abstract

Merkel cell carcinoma (MCC) is a rare, aggressive cutaneous malignancy. Nodal status has prognostic significance. We sought to analyze for factors predictive of survival and explore the significance of lymph node status and indication for sentinel lymph node biopsy in patients with MCC. A review was undertaken of 136 patients presenting with MCC at our institution between 1980 and 2008. Patient and tumor characteristics, treatment, and patterns of relapse were analyzed. Ninety patients presented with stage I disease, and 46 presented with stage II disease. The median follow-up time was 21 months. In all, 74 patients developed relapse with the commonest site of relapse in the regional lymph nodes. A total of 24 patients developed nodal relapse without prior treatment of the nodal basin. The 5-year survival was 62% and the median disease-free interval was 16 months. Radiotherapy was associated with a better disease-free survival (P < .001) and overall survival was worse as the number of involved lymph nodes increased (P = .03). This was a retrospective review with a prolonged accrual time. A high rate of nodal relapse occurred in patients with stage I disease who had undergone treatment of the primary site only. These patients may have benefited from sentinel lymph node biopsy and subsequent treatment of the nodal basin if micrometastatic disease was present, as the number of involved nodes impacted negatively on survival. Conversely, sentinel lymph node biopsy may be used to select those patients with clinical stage I disease who may avoid elective nodal treatment. Radiotherapy should have a routine role in the management of MCC.