[Effect of topotecan as a second line treatment in small cell lung cancer patients. Preliminary report]

Abstract

Introduction: Small cell lung cancer (SCLC) is an aggressive malignancy with high propensity for early regional and distant metastases. Response rate to first-line chemotherapy is high but typically short-therm. All patients with extensive disease and majority with limited disease have recurrence of disease. The choice of second-line chemotherapy in case of progression depends on many factors, including type of first-line chemotherapy, response to treatment, progression-free survival and patients' performance status. No standard second-line treatment has been established until recently. Monotherapy with topotecan is widely used in second-line treatment especially in patients in poor performance status.

Material and methods: The aim of the study was to evaluate the results of monotherapy with topotecan. We also determined the predictive markers which could affect the therapeutic effect of topotecan. The examined group consisted of 42 patients with extensive stage of SCLC. Cox regression model was used to establish adverse factors, which were prognostic for overall survival of our patients divided into two groups according to administrated chemotherapy: 21 topotecan-treated and 21 standard chemotherapy-treated. Six variables that gave a maximum hazard ratio (HR) were used in the final model, e.g.: the age above 65 (HR = 2.35), anemia (HR = 1.83) and poor performance status (HR = 1.51). These variables scored the points according to their prognostic significance and HR.

Results: In Kaplan-Meier analysis, in the group of patients treated with topotecan, the higher survival probability was noted for patients scored below 10 points than for patients scored above 10 points. The prognostic scale was not useful for patients with other scheme of chemotherapy. Five partial responses (24%) in topotecan-treated patients were noted.

Conclusions: Precise qualification of patients to topotecan monotherapy in second-line treatment may be effective to prolong survival and increase the percentage of SCLC patients with objective response.