Chemotherapy for patients with locally advanced or metastatic Merkel cell carcinoma.

BACKGROUND: Merkel cell carcinoma (MCC) is a highly malignant skin neoplasm. Regional lymph node and distant metastasis occur in 20-52% of patients. The role of chemotherapy in the treatment of patients with this rare tumor is unclear.
METHODS: An exhaustive analysis of the literature (1980-1995) describing chemotherapy for patients with locally advanced or metastatic MCC was performed. All available published medical records (n = 101 patients) were entered in a database. In addition, data on six additional patients given chemotherapy during this time frame in Lyon, France, were included in the database.
RESULTS: For the 107 patients, the overall objective response rate to first-line chemotherapy was 61% (61 of 101 evaluable patients). The response rate was 57 % (41 of 72) for patients with metastasis and 69% (20 of 29) for patients with locally advanced tumors. No clinical parameter was found to be correlated to response to chemotherapy. A high rate of toxic death during first-line treatment (n = 7.7%) was reported for these patients. The median overall survival from the date of chemotherapy initiation was 9 months for patients with metastasis and 24 months for patients with locally advanced tumors. The projected overall survival at 3 years was 17% for patients with metastasis and 35% for patients with locally advanced tumors. Progression after first-line chemotherapy was associated with significantly worse survival for patients with metastasis. Rates of response to second-line (n = 33) and third-line (n = 10) chemotherapy were 45% and 20%, respectively.
CONCLUSIONS: MCC is chemosensitive but rarely chemocurable in patients with metastasis or locally advanced tumors. A high incidence of toxic death due to chemotherapy is reported in the literature.