The natural history and management of Merkel cell carcinoma of the skin: a review of 22 patients treated at the Royal Marsden Hospital.

Merkel cell carcinoma is a rare skin malignancy, which primarily affects the elderly. Currently, there is only limited data on the natural history of this condition and no consensus on its optimum management. We have reviewed the natural history and management of 22 patients with Merkel cell carcinoma, who were treated at the Royal Marsden Hospital between 1985 and 1994. The median age at diagnosis was 75 years (range 55-96), with the head and neck region being the most common site of disease (nine patients: 41%). Seventeen patients (77%) presented with skin disease, three (14%) with regional lymphadenopathy and two (9%) with metastatic disease. Of the Stage I patients, 41% developed local recurrence postoperatively at a median time to relapse of 12 months. Those with head and neck disease had the highest risk of local recurrence, which occurred in 62.5% of this group. Stage I patients also had a high risk of disease progression, with 53% developing regional lymphadenopathy or visceral metastases. The median survival for all disease stages was 47 months. The treatment of unresectable primary or recurrent disease with radiotherapy led to valuable long term control in four of nine patients treated. Six courses of chemotherapy were administered; one brief complete response was observed, occurring in a patient treated with cyclophosphamide, vincristine and doxorubicin. The data in this study confirms the predilection for the elderly and the aggressive nature of Merkel cell carcinoma, with only four of 17 Stage I patients remaining disease free. To clarify the role of adjuvant postoperative radiotherapy and to establish the appropriate use of chemotherapy in metastatic spread of this rare malignancy will require further studies with multicentre cooperation.