title: Decreased topotecan platelet toxicity with successive topotecan treatment cycles in advanced ovarian cancer patients.
abstract: The dose-limiting toxicities of the DNA topoisomerase I inhibitor topotecan are hematological. We prospectively analyzed the platelet toxicity pattern in patients receiving topotecan to optimize the clinical management of topotecan hematotoxicity. Twenty-one advanced ovarian cancer patients, all pretreated with cisplatin and paclitaxel, were treated with 1.25 mg/m2/day topotecan as a 30 min infusion for 5 days, every 3 weeks. No prophylactic granulocyte colony stimulating factor (G-CSF) was given. No topotecan dose reduction was planned according to hematologic toxicity. One hundred and thirty-three topotecan courses were administered (median per patient 6; range: 1-15). Despite no dose reduction, the mean platelet nadir values were significantly less pronounced at cycle 2 than at cycle 1 (82 versus 46 x 10(3)/mm3, p=0.0007). Similar differences were found between cycle 1 and any following cycle. The percent of patients experiencing grade 4 thrombocytopenia decreased from 43% at the first cycle, to 15 and 19% at the second and third courses, respectively (p=0.058). We conclude that the currently recommended topotecan schedule is feasible in heavily pretreated ovarian cancer patients without prophylactic G-CSF. The severity of topotecan-induced thrombocytopenia is maximal at the first cycle but significantly decreases from the second cycle in the absence of dose reduction.
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D002945:Cisplatin / Q000008:administration & dosage; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000188:drug therapy*; D017239:Paclitaxel / Q000008:administration & dosage; D010976:Platelet Count; D011446:Prospective Studies; D013921:Thrombocytopenia / Q000139:chemically induced*; D019772:Topotecan / Q000008:administration & dosage / Q000009:adverse effects*