Background: Recent reports have suggested the efficacy of amrubicin (AMR) for relapsed small-cell lung cancer (SCLC). However, doses of AMR in these reports were 40 mg/m(2) or 45 mg/m(2), and severe and frequent myelosuppression were observed. Such side effects are occasionally intolerable, as serious myelosuppression may induce fatal infections. To overcome this clinical problem, we investigated whether 35 mg/m(2) of AMR administration with routine prophylactic use of granulocyte-colony stimulating factor (G-CSF) can reduce myelosuppression, while maintaining efficacy.
Methods: Between July 2003 and November 2008, 30 relapsed SCLC patients receiving 35 mg/m(2)/day of AMR were evaluated. Amrubicin was administered on days 1-3 every 3 or 4 weeks. Routine prophylactic use of G-CSF was performed beginning on day 8 and continuing for at least 5 consecutive days or until neutrophils recovered to the normal level.
Results: The median number of treatment cycles was four (range 1-9). No complete responses and 13 partial responses were observed, with response rates of: overall 43% (95% confidence interval [CI]: 26-63%); sensitive cases 33% (95% CI: 10-65%); and refractory cases 50% (95% CI: 26-74%) (p=0.4651). The disease control rate (partial response and stable disease) was 80% (95% CI: 61-92%). The progression-free survival times were: overall 4.2 months (95% CI: 3.2-5.2 months); sensitive cases 4.7 months (95% CI: 2.6-5.4 months); and refractory cases 3.5 months (95% CI: 2.6-5.2 months) (p=0.7124). The median OS times were: overall 9.6 months (95% CI: 7.2-12.5 months); sensitive cases 8.4 months (95% CI: 4.6-13.4 months); and refractory cases 11.0 months (95% CI: 6.5-12.6 months) (p=0.9315). The 1-year survival rate was 33%. Regarding grade 3/4 hematological toxicities: leukopenia (47%); neutropenia (50%); anemia (30%); and thrombocytopenia (33%) were observed. Febrile neutropenia occurred in three patients (10%). Transfusions of red blood cells and platelets were performed for eight (27%) and one (3%) patients, respectively. Treatment-related deaths and grade 3/4 non-hematological toxicities were not observed at all.
Conclusions: Considering both safety and efficacy, AMR at a dose of 35 mg/m(2) with routine prophylactic use of G-CSF may be more desirable for the treatment of relapsed SCLC in clinical practice.
Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.