The addition of erlotinib to gemcitabine and cisplatin does not appear to improve median survival in metastatic pancreatic cancer.

Abstract

Metastatic pancreatic cancer carries a poor prognosis, with median survival on the order of several months. There is evidence that combining gemcitabine with either erlotinib or cisplatin may be superior to single agent gemcitabine in patients with good performance (PS 0-1). We retrospectively compared outcomes of patients treated with either the three drug regimen of gemcitabine, cisplatin, and erlotinib (GCE) or the doublet of gemcitabine and cisplatin (GC) in order to assess the potential benefit of erlotinib. We also evaluated the role of erlotinib among smokers and non-smokers. We retrospectively analyzed 145 patients who presented between 2006 and 2009 with previously untreated metastatic pancreatic cancer initially treated at the M.D. Anderson cancer center with either GC or GCE. Information on tumor characteristics and overall survival time (OS) was collected by medical record review. Kaplan-Meier curves were used to estimate OS. Log rank tests were used to compare OS between groups. The Cox proportional hazards regression model was used to evaluate the ability of patient prognostic variables or treatment group to predict OS. A total of 71 patients were treated with GC, while 74 were treated with GCE. Cox analyses found no significant difference in overall survival (median 5.5 vs. 8.0 months, respectively, p-value=0.1). Small sampling numbers may have contributed to this result. One year survival was 23 % in the GCE group and 13 % in the GC group. Patients with poor performance status (PS=2-3) had worse survival as compared to patients with better performance status (PS=0-1, p=0.001). As in earlier studies, patients treated with more lines of therapy tended to have better survival (p <0.0001), and CA19-9 was found to be a significant predictor for OS (p=0.001). No statistical evidence of a survival difference was found between smokers and non-smokers in both treatment groups (p=0.72). In conclusion, though there was a trend towards improved survival with the addition of erlotinib to gemcitabine and cisplatin, this does not reach statistical significance.