Introduction Lung cancer is relatively common in patients with fibrotic ILD. The presence of ILD can influence patient selection for treatment and raises concerns about treatment risks and outcomes.
Aim To investigate the prevalence of ILD among patients with advanced lung cancer who received chemotherapy as an initial treatment and to explore clinical features and prognosis in this group compared to other lung cancer patients without ILD.
Method We studied consecutive lung cancer patients in the West of Scotland Lung Cancer Database treated with chemotherapy in one year (2017). Pre-treatment chest CT scans were evaluated by two radiologists with double reading of a proportion to assess consistency. If present, ILD was further classified into 3 groups: usual interstitial pneumonia (UIP), possible UIP, and inconsistent with a UIP pattern according to ATS/ERS/JRS/ALAT guidance.
Results 448 patients were included in the study, with 44 (9.8%) identified as having ILD (15 UIP, 14 possible UIP and 15 inconsistent with UIP). Compared with those without ILD, patients with ILD were older (mean:72 vs 66 years, p<0.001), predominantly male (77% versus 46%, P >0.01), had a significantly higher performance status score (p=0.014) and earlier TNM stage (49% stage IV versus 70% stage IV, p=0.009). Small Cell Lung Cancer was the most common histologic type in the ILD group (50%), while in the non-ILD group adenocarcinoma (37.4%) was followed by squamous cell carcinoma (36.4%). Pre-treatment pulmonary function tests showed that patients with ILD had significantly lower forced vital capacity (FVC) (median: 92% versus 105%, P = 0.002) and diffusing capacity for carbon monoxide (DLco) (median: 55% versus 72.5%, P<0.001).
Median survival times for ILD and non-ILD group were not significantly different at 319 and 344 days respectively (log-rank test P=0.3).
Conclusion Lung cancer patients with concomitant ILD have specific demographic, histological and functional features. However, concomitant ILD does not confer a survival disadvantage after receiving chemotherapy in this group with advanced lung cancer. These patients should not be denied the chance of treatment based solely on their underlying ILD.
