The North Central Cancer Treatment Group designed a phase II trial to assess the efficacy and toxicity of topotecan in patients with unresectable malignant pleural mesothelioma. Twenty-two previously untreated patients with unresectable pleural mesothelioma and good performance status (Eastern Cooperative Oncology Group performance status 0, 1, or 2) were enrolled on this trial from October 1993 through July 1994. Nineteen men and three women, median age 66 years (range, 44-78 years), were treated with topotecan 1.5 mg/m2 intravenously over 30 minutes daily for 5 days at 3-week intervals until toxicity, progression of disease, or a patient decided to discontinue treatment. There were seven patients with measurable disease and 15 with evaluable disease; all were assessable for response and toxicity. A total of 113 cycles of treatment were given, for a median of three cycles (range, 1-26 cycles). Myelosuppression was the most frequent toxicity. Eighteen of 21 patients (86%) experienced grade 3 or 4 neutropenia during the initial treatment cycle. The median neutrophil nadir was 0.5 × 103/μl (range, 0.1-1.6 × 103/μl), and the median platelet nadir was 127 × 103/μl (range, 18-460 × 103/μl). Other toxicities more than grade 2 included malaise (two patients), and anorexia, infection, fever, pulmonary, and cardiac in one patient each. There were no objective responses, and 18 patients had stable disease for a median of 74 days. The median survival for all patients was 230 days, with 23% alive at 1 year. Topotecan as administered in this trial is reasonably well tolerated; however, the response rate was insufficient to warrant additional study in pleural mesothelioma.
From the Saskatoon Cancer Centre (A.W.M.), Saskatoon, Canada; Mayo Clinic Scottsdale CCOP (R.F.M.), Scottsdale, Arizona, U.S.A.; Mayo Clinic and Mayo Foundation (H.D.T., J.G., J.C.B., J.R.J.), Rochester, Minnesota, U.S.A.; Geisinger Clinical Oncology Program (S.N.), Danville, Pennsylvania, U.S.A.; Ochsner Community Clinical Oncology Program (C.G.K.), New Orleans, Louisiana, U.S.A.; Nebraska Oncology Group-Creighton University, University of Nebraska Medical Center and Associates (J.A.M.), Omaha, Nebraska, U.S.A.; Toledo Community Clinical Oncology Program (P.L.S.), Toledo, Ohio, U.S.A.
Conducted as a trial of the North Central Cancer Treatment Group and supported in part by Public Health Service Grants CA-25224, CA-37404, CA-60276, CA-35448, CA-35272, CA-35415, CA-52352, and CA-35269 from the National Cancer Institute, Department of Health and Human Services.
Additional participating institutions included: Cedar Rapids Oncology Project CCOP, Cedar Rapids, Iowa (Martin Wiesenfeld, M.D.), and Duluth Community Clinical Oncology Program, Duluth, Minnesota (Ron J. Kirschling, M.D.).
Address correspondence and reprint requests to Dr. James R. Jett, North Central Cancer Treatment Group, 200 First Street Southwest, Rochester, MN 55905, U.S.A.