Is cigarette smoke associated with increased catabolism of gemcitabine in patients with advanced solid tumors

2602 Background: Cigarette smoking can accelerate chemotherapy metabolism and result in lower plasma concentrations of the chemotherapeutic agent. Reduced drug levels may lead to undertreatment in smokers and, conversely, increased treatment-related neutropenia in nonsmokers. Methods: An IRB-approved retrospective chart review was performed on 151 patients with solid tumor malignancies who received gemcitabine alone or in combination with oral chemotherapy agents from July 1, 2009 to June 30, 2011 at the University of Michigan. Using logistic regression, we compared toxicity, including neutropenia, and smoking history measured in pack-years in smokers vs. nonsmokers to ascertain whether cigarette smoking is an independent factor predictive of toxicity to gemcitabine. Results: Tumor types included breast (9.3%), lung (4.6%), pancreatobiliary (70.9%), or other/unknown primary (15.2%). Most patients had advanced disease (stage III-IV; 78.1%); specifically, of the pancreatobiliary cohort (PB; n=107), 77.6% pa...