Interstitial Lung Disease Associated with Lung Cancer: A Case–Control Study

Interstitial lung disease (ILD) seems to be associated with an increased risk of lung cancer (LC) and to have a poorer prognosis than LC without ILD. The frequency of ILD in an LC cohort and its prognosis implication need to be better elucidated. This retrospective, observational, cohort study evaluated the frequency of ILD among LC patients (LC&ndash
ILD) diagnosed over a 2-year period. LC&ndash
ILD patients&rsquo
characteristics were compared to those with LC without ILD (LC&ndash
noILD). Lastly, we conducted a case&ndash
control study within this cohort, matching three LC&ndash
noILDs to each LC&ndash
ILD patient, to evaluate the ILD impact on LC patients&rsquo
prognoses. Among 906 LC patients, 49 (5.4%) also had ILD. Comparing LC&ndash
ILD to LC&ndash
noILD patients, respectively, more were men (85.7% vs. 66.2%
p = 0.02)
adenocarcinomas were less frequent (47.1% vs. 58.7%, p = 0.08)
median [range] and overall survival was shorter: (9 [range: 0.1&ndash
39.4] vs. 17.5 [range: 0.8&ndash
50.4] months
p = 0.01). Multivariate analysis (hazard ratio [95% confidence interval]) retained two factors independently associated with LC risk of death: ILD (1.79 [1.22&ndash
2.62]
p = 0.003) and standard-of-care management (0.49 [0.33&ndash
0.72]
p &lt
0.001). Approximately 5% of patients with a new LC diagnosis had associated ILD. ILD was a major prognosis factor for LC and should be taken into consideration for LC management. Further studies are needed to determine the best therapeutic strategy for the LC&ndash
ILD population.