Influencing factors of efficacy and long‐term use of amrubicin in patients with small cell lung cancer

BACKGROUND: Amrubicin (AMR) has become the standard of care for post‐relapse small cell lung cancer (SCLC). It has also been reported to achieve long‐term disease control in patients with good treatment response. However, the optimal patient population for whom AMR is effective and the factors associated with long‐term disease control are yet to be identified. The aim of the study was to identify the clinical characteristics and factors associated with long‐term disease control in patients with recurrent SCLC who would benefit from AMR therapy. METHODS: The clinical records of 33 patients diagnosed with recurrent SCLC and treated with AMR were retrospectively reviewed. Clinical information was compared between patients who achieved disease control (effective group) and who developed disease progression (noneffective group) on the first efficacy assessment after AMR and between patients who continued AMR for more than seven cycles (maintenance group) and those who terminated treatment after 1–6 cycles (discontinuation group). RESULTS: The noneffective group included significantly more patients with AMR dose reductions after the second cycle (p = 0.006). AMR dose reduction was an independent risk factor for disease progression. The maintenance group had significantly lower pretreatment lactate dehydrogenase (LDH) levels than the discontinuation group (p = 0.046). A high LDH level was an independent risk factor for short AMR discontinuation. Overall survival was significantly longer in the effective group than in the noneffective group (p < 0.001). CONCLUSIONS: In AMR therapy for patients with relapsed SCLC, continuation of AMR without dose reduction after the second cycle may contribute to disease control and prolonged survival.