Prognostic Significance of Preexisting Interstitial Lung Disease in Japanese Patients With Small-Cell Lung Cancer

BackgroundIn Japan, iatrogenic acute exacerbation of interstitial lung disease (ILD) is a serious complication in patients with lung cancer and simultaneous ILD. Results of some reports suggest that patients with ILD and small-cell lung cancer (SCLC) might benefit from chemotherapy, but the influence of ILD on prognosis is unclear.Patients and MethodsRetrospective study of patients with SCLC with or without ILD. Between April 2006 and March 2011, 122 patients with SCLC who were receiving platinum-based combination chemotherapy participated.ResultsTwenty-eight patients (23.0%) had ILD at diagnosis. Pneumonitis associated with chemotherapy, including acute exacerbation–ILD was significantly increased in patients with preexisting ILD (8/28 vs. 2/94; P = .0001). In patients receiving chemotherapy alone, response rates and median progression-free survival of first-line chemotherapy in patients with or without preexisting ILD was not significantly different (P = .26; 20/26 vs. 52/60 and P = .089; 4.4 months vs. 5.4 months, respectively). The median overall survival of all patients was 15.5 months, but those without preexisting ILD survived significantly longer (P = .0010; 17.8 months vs. 10.7 months). Multivariate analysis revealed that performance status of 0 or 1 (hazard ratio [HR] 0.19 [95% confidence interval {CI}, 0.10-0.37]; P < .0001) limited disease (HR 0.42 [95% CI, 0.23-0.73]; P = .0017), and no preexisting ILD (HR 0.36 [95% CI, 0.19-0.69]; P = .0027) were significantly associated with longer overall survival.ConclusionPatients with SCLC and ILD might benefit from chemotherapy, but preexisting ILD is an independent prognostic factor for poorer survival.