Treatment and Prognosis of Patients with Lung Cancer and Combined Interstitial Lung Disease

SIMPLE SUMMARY: Interstitial lung disease (ILD) is associated with a higher risk of lung cancer. The impact of underlying ILD on cancer’s clinical characteristics, treatment strategies, and outcome is unclear, particularly in Caucasian populations. In this article, we reviewed the files of all patients diagnosed with lung cancer in a 38-month period and compared the patients with and without underlying interstitial changes for population and lung cancer characteristics, treatment and clinical outcome. Seven percent of patients with lung cancer had associated ILD at diagnosis. They were significantly older, but no other significant difference in population or cancer characteristics was observed. Patients with combined lung cancer and ILD had a worse clinical outcome even when similar treatment modalities were offered. Therefore, the choice of aggressive treatment strategies needs to be made carefully, with an awareness of the risk of acute exacerbation of ILD. ABSTRACT: Background: Interstitial lung disease (ILD) is associated with a higher lung cancer (LC) risk and may impact cancer’s clinical characteristics, treatment strategies, and outcomes. This impact’s extent is unclear, particularly in Caucasians. Methods: In this retrospective observational study, we reviewed the files of all LC patients diagnosed in a 38-month period. Expert radiologists reviewed the computed tomography scans performed at diagnosis. Patients with LC and ILD (n = 29, 7%) were compared to those without ILD (n = 363, 93%) for population and cancer characteristics, treatments, and clinical outcomes. Results: Patients with LC and ILD were older (73 ± 8 vs. 65 ± 11 years; p < 0.001). There was no significant difference in LC histology, localization, stage, or treatment modalities. The respiratory complication rate after cancer treatment was significantly higher in the ILD group (39% vs. 6%; p < 0.01). Overall survival rates were similar at 12 (52% vs. 59%; p = 0.48) and 24 months (41% vs. 45%; p = 0.64) but poorer in the ILD group at 36 months, although not statistically significant (9% vs. 39%; p = 0.06). The ILD group had a higher probability of death (hazard ratio (HR) = 1.49 [0.96;2.27]), but this was not statistically significant (p = 0.06). In a Cox regression model, patients with ILD treated surgically had a significantly higher mortality risk (HR = 2.37 [1.1;5.09]; p = 0.03). Conclusions: Patients with combined LC and ILD have worse clinical outcomes even when similar treatment modalities are offered.