MUC-1 (CA 15-3 antigen) as a highly reliable predictor of response to EGFR inhibitors in patients with bronchioloalveolar carcinoma: an experience on 26 patients

Background: Bronchioloalveolar carcinoma (BAC) is a histological subtype of non-small cell lung cancer (NSCLC), particularly of adenocarcinoma. Given its multifocality and the poor activity of chemotherapy, there is no established treatment for BAC, although promising results have been achieved with inhibitors of the epidermal growth factor receptor (EGFR). No tumor marker has been validated in the diagnosis and follow-up of lung cancer, in particular to predict the outcome of treatment with EGFR inhibitors. Purpose: As CA 15-3 antigen serum levels are reported to be pathologically abnormal in adenocarcinoma of the lung, we chose this tumor marker to monitor treatment with EGFR inhibitors of patients affected by adenocarcinoma with BAC features or pure BAC. Patients and methods: We collected data from 26 consecutive Caucasian patients with BAC, mostly women and never smokers, who received EGFR inhibitors. Results: We noticed that all patients with normal CA 15-3 serum levels at baseline (15/26, 57.7%) showed a response to EGFR inhibitors, whereas all patients with abnormal CA 15-3 serum levels (11/26, 42.3%) did not. Conclusion: Our data suggest that CA 15-3 levels might be a predictive factor for the response to EGFR inhibitors in patients with BAC.