Merkel cell carcinoma: report of ten cases with emphasis on clinical course, treatment, and in vitro drug sensitivity.
BACKGROUND
Merkel cell carcinoma (MCC) is an uncommon primary neuroendocrine skin tumor most often seen in the elderly. The clinical course varies. Treatment is controversial and few data on drug sensitivity are available.


OBJECTIVE
We evaluated the clinical course and treatment of 10 MCC patients and determined MCC chemosensitivity.


METHODS
Clinical records as well as laboratory and histopathologic data from 10 patients with MCC treated in our department were examined. Chemosensitivity to various chemotherapeutic agents and interferons of MCC cells from four patients was determined in a soft agar clonogenic assay.


RESULTS
MCC behaved as an aggressive tumor with early and frequent local relapses (4 of 10 patients at a 2.2-month average), regional (4 of 10 patients at 2.5 months), and distant metastases (5 of 10 patients 9.6 months after excision of the primary tumor). In all but one patient, regional metastases preceded distant ones. Metastatic spread was associated with an average survival of 21 months from the initial diagnosis. Long-term survival (53+ and 65+ months) was observed in two women. Wide excision of the primary tumor, alone or combined with adjuvant chemotherapy and radiotherapy, was the most effective treatment. In advanced disease, chemotherapy and radiotherapy were not able to induce long-term remission. In vitro assays for MCC drug sensitivity revealed cisplatin, doxorubicin, and vindesine to be the most active.


CONCLUSIONS
MCC has a poor prognosis in advanced stages; therefore the primary tumor should be aggressively treated. The in vitro clonogenic assay may help to identify the chemosensitivity profile of MCC and to optimize chemotherapy protocols.
Krasagakis
K
K
Department of Dermatology, University Medical Center Benjamin Franklin, Free University of Berlin, Germany.
Almond-Roesler
B
B
Zouboulis
C C
CC
Tebbe
B
B
Wartenberg
E
E
Wolff
K D
KD
Orfanos
C E
CE
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use; D015266:Carcinoma, Merkel Cell / Q000175:diagnosis / Q000628:therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012878:Skin Neoplasms / Q000175:diagnosis / Q000628:therapy; D014410:Tumor Stem Cell Assay
D000970:Antineoplastic Agents