Factors influencing response to second-line treatment with teniposide (VM26) in patients with progressive small cell lung cancer (SCLC)

Twenty-eight patients with small cell lung cancer (SCLC), 12 with limited (LD) and 16 with extensive (ED) disease, 22 of them relapsed to first-line treatment and 6 not responsive, were treated with a single-agent second-line treatment consisting of teniposide (VM26) 60 mg/m2, i.v. on days 1 to 5, every three weeks, until progression. After a minimum of two courses, we observed no complete response, 7 (LD/ED = 4/3) partial responses (25%), 4 (LD/ED = 2/2) minor responses (14%), and 17 (LD/ED = 6/11) with no change (61%). Median duration of response (partial plus minor) was 3.5 months (range 1-8). Median duration of survival, from VM26 administration, was in LD 6 months (range 2.5-11), in ED 3 months (range 1.5-6) and in all patients 4 months (1.5-11). Correlating the 11 responses with major prognostic variables present in the patients, we observed that KPS > 70, few initial courses of PL/VP16 and response to first-line treatment were significant determinants for successful salvage treatment. This study suggests the need to consider detailed patient characteristics of exposure to previous treatment before prompting new drug phase II studies on SCLC.