The Value of Topotecan in the Second-Line Treatment of Small-Cell Lung Cancer. Preliminary Report

Introduction: Small-cell lung cancer (SCLC) is a highly aggressive malignancy with a high potential for growth and spread. Responses to first-line treatment are common but generally short-lived. Nearly all patients with extensive disease and most with limited disease relapse. The choice of second-line treatment depends on many factors, including previous treatment, previous response, time from completion of previous treatment to progression, and performance status. The most common chemotherapy regimen used in the second-line setting is the one which has led to long-term remission in the first-linesetting. Topotecan monotherapy is increasingly used in second-line treatment, especially in patients with poor performance status. Material and methods: Our aim was to evaluate the outcomes of topotecan monotherapy and to determine the effects of predictive/prognostic factors on the efficacy of the treatment. We investigated 42 patients with SCLC with extensive disease. Twenty-one subjects received topotecan monotherapy and the remaining ones received other chemotherapy regimens. Using the Cox proportional hazards model we demonstrated that such factors as the following reduce overall survival to the greatest degree: age over 65 years (HR = 2.35), anaemia (HR = 1.83), and poor performance status (HR = 1.51). A predictive/prognostic scale was created taking into account 6 factors that were assigned scores depending on the hazard ratio values. Results: The survival probability of subjects managed with topotecan was non-significantly higher (P = 0.097) in the group of subjects who scored less than 10, compared to the group scoring 10 or more on our proposed scale. The scale failed to prove useful for predicting the course of SCLC in patients receiving other chemotherapy. Objective response to topotecan was observed in 5 patients (24%). Conclusions: Precise qualification for topotecan monotherapy may prolong survival and increase the response rate.