Outcomes of advanced stage non-small cell lung cancer (NSCLC) patients reexposed to platinum-based chemotherapy upon progression

Abstract

17136 Background: Platinum-based chemotherapy (PtCT) is the standard 1st-line treatment for advanced stage NSCLC patients. Nearly all patients (pts) that respond to 1st-line CT will relapse and some of them will be candidates for 2nd-line CT. There is no consensus definition of sensitive or resistant pts to PtCT and there are conflicting results about the relationship between response to prior PtCT and response to a 2nd-line reexposure. The aim of this study was to evaluate the outcomes of a subset of pts considered sensitive to platinum, who were reexposed to a PtCT regimen as 2nd-line CT. Methods: Based on a criterion of disease progression > 6 months of completing 1st-line as a hallmark platinum-sensitivity, pts were retrospectively selected. We reviewed the outcomes of 11 advanced NSCLC pts (stages IIIB or IV) treated between Jan 2000 and Jun 2005 at 1st-line with a PtCT (cisplatin or carboplatin combined to etoposide) and who upon progression were reexposed to a regimen of Carboplatin plus etoposide. Pts were evaluated for overall (OS) and progression-free survival (PFS) after 1st- and 2nd-line CT by Kaplan-Meyer method. Results: There were 6 women (54.5%) and 5 men (45.5%). Median age was 62 (range 49–78) and adenocarcinoma was the most prevalent histology (54.5%). At 1st-line CT, 6 patients (54.5%) were stage IIIB and ECOG PS 0/1 were 36.4 and 63.6%, respectively. The median number of cycles per patient was 6 (range 2–8) at 1st-line and 4 (range 2–4) at 2nd-line treatment. With a median follow-up of 29 months, there were 4 deaths (36.5%) with a median OS of 49 months (CI 95%; 29.38–68.62). The median PFS after first-line was 17 months (IC 95%; 13.87–20.13). To date, 7 pts have progressed after 2nd-line CT with a median PFS of 8 months (IC 95%; 5.92–10.09). Conclusions: This subset of pts with longer progression-free interval (> 6 months) after 1st-line PtCT seems to remain sensitive to platinum compounds upon disease progression. Despite the high proportion of stage III in our sample, based on the long DFS and OS observed, it seems that this population has a more favorable biology than the general population with NSCLC. Further studies, in particular pharmacogenetic analyses, are needed in order to better characterize and treat this population. No significant financial relationships to disclose.