A B S T R A C T PurposeInhibitors of the epidermal growth factor receptor (EGFR) tyrosine kinase have demonstrated modest anticancer activity in advanced bronchioloalveolar carcinoma (BAC). We conducted a phase II study to evaluate cetuximab for the treatment of advanced BAC. Patients and MethodsPatients with advanced-stage pure BAC or adenocarcinoma with BAC features, fewer than two prior chemotherapy regimens, and Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2 were eligible. Those with prior EGFR inhibitor therapy were excluded. Cetuximab was given as a weekly intravenous infusion at 250 mg/m 2 after an initial loading dose of 400 mg/m 2 in week 1. The primary end point was determination of response rate. EGFR and KRAS mutations were evaluated by pyrosequencing. ResultsSeventy-two patients were enrolled and 68 met eligibility requirements. Characteristics of patients included median age, 71 years; sex, 57% females; PS 0 or 1, 88% of patients; and smoking status, 19% never-smokers. Central pathology review confirmed the diagnosis in 45 of 49 available specimens. Approximately 50% of patients received more than two cycles of therapy (Ͼ 8 weeks). Skin rash was the most common toxicity (grade 3, 15%). The confirmed response rate was 7%, and stable disease was observed in 35%. The median survival and progression-free survival were 13 and 3.3 months, respectively. Only one of the six patients with an EGFR mutation and one of the seven patients with a KRAS mutation had a partial response. ConclusionCetuximab was associated with modest efficacy in patients with advanced BAC, despite a low response rate. EGFR and KRAS mutations were not predictive of response to cetuximab.