A nomogram for the prediction of the survival of patients with advanced non-small cell lung cancer and interstitial lung disease

Background: Lung cancer is frequently accompanied by interstitial lung disease (ILD), and the overall survival (OS) of patients with these comorbidities is poor. Thus, we developed a nomogram for the prediction of the OS of patients with advanced non-small cell lung cancer (NSCLC) and ILD.

Patients and methods: Patients with wild-type gene advanced NSCLC with and without ILD who underwent chemotherapy between 2014 and 2019 were enrolled in the present study. The 0.5- and 1-year progression-free survival (PFS) and overall survival (OS) times of patients with and without ILD were determined using the Kaplan-Meier method. Cox regression was used to assess the prognostic value of clinical factors for patients with ILD. Based on the multivariate regression results, a nomogram for survival prediction was developed. The nomogram was validated using calibration curve.

Results: Data from 155 patients with lung cancer and ILD and 118 matched patients with lung cancer alone who were receiving first-line chemotherapy were analyzed. The first-line chemotherapy regimens were paclitaxel + carboplatin, pemetrexed + carboplatin, gemcitabine + carboplatin, and other. The median PFS and OS were significantly shorter in patients with than in those without ILD (3.0 vs. 7.0 months [p < 0.001] and 7.0 vs. 15.0 months (p < 0.001), respectively). Multivariate analysis showed that the lymphocyte count (hazard ratio [HR] 2.38; 95% confidence interval [CI], 1.44-3.94; p = 0.01), partial pressure of oxygen (PaO₂ ; HR, 1.37; 95% CI, 1.03-1.82; p = 0.03), and chemotherapy regimen were independently associated with prognosis. The nomogram showed good discriminatory ability [C-index = 0.69 (95% CI, 0.49-0.82)]. Calibration curves showed that predicted and actual prognoses were consistent.

Conclusion: This nomogram can aid the prediction of the OS of patients with advanced NSCLC and ILD.