Improved therapeutic index of lower dose topotecan chemotherapy in recurrent ovarian cancer

Objective. Topotecan (1.5 mg/m(2)) administered daily for 5 consecutive days of a 21-day cycle is an established chemotherapeutic regimen in recurrent ovarian cancer. However, noncumulative myelosuppression has limited its use by many clinicians. We sought to determine whether a lower dose of topotecan could provide comparable tumor activity and higher tolerability in pretreated ovarian cancer patients. Methods. A retrospective chart review was conducted on recurrent ovarian, peritoneal, or fallopian tube cancer patients with measurable disease or elevated cancer antigen 125 levels (evaluable disease). Patients were treated with topotecan (1.0 mg/m(2)) given by 30-min intravenous infusion for 5 consecutive days every 21 days until disease progression or unacceptable toxicity. Results. Treatment records from 37 women who had been treated with a median of 3 courses (range, 1 to 17) of lower dose topotecan were evaluated; all were evaluable for tolerability and 36 were evaluable for response. Patients had received a median of 3 (range, 1 to 6) previous treatments. The overall response rate was 22% (8/36); the response rates for patients with evaluable disease and measurable disease were 35.7 (5/14) and 13.6% (3/22), respectively. An additional 8 patients (22%) achieved stable disease. Grade 4 neutropenia, thrombocytopenia, and anemia occurred in 48.6, 5.4, and 5.4% of patients, respectively. Granulocyte colony-stimulating factor support was used in 37% of patients, including 5 who experienced febrile neutropenia. Conclusion. Topotecan at 1.0 mg/m(2) x 5 days every 21 days is active in platinum- and paclitaxel-resistant ovarian cancer, with significant improvements in hematologic toxicity. In heavily pretreated patients-topotecan can be safely given at reduced doses without apparent loss of efficacy. (C) 2001 Academic Press.