Oral etoposide for merkel cell carcinoma in patients previously treated with intravenous etoposide

We describe three patients with advanced Merkel cell carcinoma who were tre ated with etoposide given orally for recurrent regional lymph node involvem ent 18 to 30 months after exposure to etoposide given intravenously. Etopos ide given orally (100 mg/day) was given for 10 to 14 consecutive days and r epeated every 21 to 28 days for a median of three courses (range: two to fo ur). Toxicity was minimal and mainly hematologic. Two patients showed a com plete response and one a partial response, all of very rapid onset. All thr ee patients are alive 6, 9, and 42 months from the start of oral treatment. Two remain progression free, and one had a recurrence I month after comple tion of chemotherapy. We suggest that orally administered etoposide, a topo isomerase II inhibitor, has a strong antitumor effect in advanced Merkel ce ll carcinoma, even in patients previously treated parenterally with the sam e drug. This action may be explained by the greater dependence of the drug' s efficacy on the duration of administration rather than the dose intensity .