Chemotherapy for non-small cell lung cancer complicated by idiopathic interstitial pneumonia

Idiopathic interstitial pneumonia (IIP) is considered to be one of the risk factors for lung cancer (LC). However, therapeutic options for patients with LC complicated by IIP are not well established. In this study, we investigated the feasibility and efficacy of chemotherapy for patients with non-small cell lung cancer (NSCLC) complicated by IIP (NSCLC-IIP). We retrospectively analyzed 22 NSCLC-IIP patients who received chemotherapy. To determine how IIP affected the clinical outcomes in NSCLC, they were compared with 276 NSCLC patients without IIP, who were treated with chemotherapy alone. The response rate (partial response + stable disease) was 72.3% (17/22), whereas the incidence of acute exacerbation (AE) was 13.6% (3/22) in NSCLC-IIP patients treated with chemotherapy. NSCLC-IIP patients had significantly shorter survival compared with NSCLC patients without IIP (P<0.001) following chemotherapy, although the response rates to chemotherapy were not significantly different between the two groups. Multivariate analysis demonstrated that, in NSCLC patients receiving chemotherapy, IIP was a significantly unfavorable factor for progression-free and overall survival. Despite similar response rates to chemotherapy, NSCLC-IIP patients showed poorer prognosis than NSCLC patients without IIP, possibly due to the natural course of IIP. Chemotherapy may be a feasible option for NSCLC-IIP, if the risks of adverse effects are acceptable.