Potential clinical prognostic factors in non-small cell lung cancer (NSCLC) patients treated with gefitinib

Abstract

7088 Background: Phase II studies have shown that gefitinib (Iressa) produces approximately a 10% response rate in previously treated patients (pts) with NSCLC. Currently, little is known about which pts are likely to benefit from treatment with gefitinib. Tobacco, gender, and histologic subtype may be important factors in response to gefitinib(M Kris et.al.,V Miller et.al.). Our objective is to evaluate potential clinical prognostic factors in NSCLC pts treated with gefitinib. Methods: Response rate, progression free interval(PFI) and survival were evaluated for 126 patients (64 female/62 male, median age 68; 67 adenocarcinomas/59 other histologies; 72 PS 0–1/53 PS 2+; 110 used tobacco/ 16 no tobacco use) who were treated with gefitinib (500 mg po day 1, then 250 mg po daily) and evaluated monthly on the expanded access trial. CT scans were performed every two months. We collected data on the pts' age, sex, performance status(PS), tobacco use, number of previous chemotherapies and date of last prior chemotherapy Results: Median follow-up was 169 days(d). Overall response rate was 5.6%(1CR,6PR) and 24 pts (19%) had stable disease. Median Kaplan-Meier survival and PFI were 172 and 59 d, respectively. The Fisher's Exact Test was used to evaluated associations. A greater proportion of patients with adenocarcinoma 85% (6/7) responded than did other histologies 14% (1/7) p=.08. Median survival was 484 d for nonsmokers and 167 d for smokers. Similarly, PFI was146 days-nonsmokers and 59 days-smokers (p<.04). Significant differences in survival were also observed for pts with PS 0–1, 231 d and PS2+, 119 d (p=.0005). A significant association was also observed between tobacco use and gender; a larger proportion of females never used tobacco. Conclusions: Longer survival and PFI were observed in pts treated with gefitinib who have never used tobacco and have PS 0–1. These data suggest further investigation of tobacco usage and PS as predictive factors of response to gefitinib, as well as the relationship between tobacco use and gender is warranted. Author Disclosure Employment or Leadership Consultant or Advisory Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration AstraZeneca AstraZeneca AstraZeneca