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

Abstract

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–ILD) diagnosed over a 2-year period. LC–ILD patients’ characteristics were compared to those with LC without ILD (LC–noILD). Lastly, we conducted a case–control study within this cohort, matching three LC–noILDs to each LC–ILD patient, to evaluate the ILD impact on LC patients’ prognoses. Among 906 LC patients, 49 (5.4%) also had ILD. Comparing LC–ILD to LC–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: 0.1–39.4] vs. 17.5 [range: 0.8–50.4] months; p = 0.01). Multivariate analysis (hazard ratio [95% confidence interval]) retained two factors independently associated with LC risk of death: ILD (1.79 [1.22–2.62]; p = 0.003) and standard-of-care management (0.49 [0.33–0.72]; p < 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–ILD population.

Survival analysis in lung cancer patients with interstitial lung disease

“…Previous studies about lung cancer and ILD (the majority of the studies have focused on patients with IPF and CPFE) have also demonstrated lower survival and higher mortality rate among patients with lung cancer and ILD as compared to patients with lung cancer only or IPF only or emphysema without lung cancer. Gibiot et al [ 6 ], found median survival of 9 months for patients with lung cancer and ILD as opposed to 18 months for those with lung cancer only. Tzouvelekis et al [ 12 ], recently reported a median survival of 14 months in patients with lung cancer and IPF from the time of lung cancer diagnosis.…”

“…In two separate meta-analyses SCC was also found to be the most common histology with 38% and 42% followed by adenocarcinoma with 31% and 34%, respectively [ 5 , 7 ]. A few studies have shown that, adenocarcinoma is the most common histologic type with SCC being second to adenocarcinoma [ 6 , 25 ]. Gibiot et al recently found adenocarcinoma to be the most common histologic type in 49 patients with lung cancer and concurrent ILD (47%) followed by SCC (20%) [ 6 ].…”

“…Previous studies have reported lower survival rate in patients with lung cancer and IPF or combined pulmonary fibrosis and emphysema (CPFE), however fibrotic lung disease initially documented on chest CT may have different patterns from the typical UIP CT pattern [ 6 , 7 ]. The coexistence of lung cancer and fibrotic lung disease may also impact survival of these patients and have dismal prognosis compared to patients with lung cancer only.…”

Pre-diagnosis neutrophil-to-lymphocyte ratio and mortality in individuals who develop lung cancer

“…It is well established that inflammatory processes are associated with risk of lung cancer [6][7][8][9], and it is plausible that an individual's systemic inflammatory profile prior to a lung cancer diagnosis may be associated with mortality. In support of this hypothesis, inflammatory conditions such as chronic bronchitis and emphysema, chronic obstructive pulmonary disease (COPD), interstitial lung disease, and diabetes are associated with increased lung cancer mortality independent of their associations with increased lung cancer risk [10][11][12][13][14][15][16][17][18][19].…”

Pre-diagnosis neutrophil-to-lymphocyte ratio and mortality in individuals who develop lung cancer

“…It is well-established that in ammatory processes are associated with risk of lung cancer [6][7][8][9], and it is plausible that an individual's systemic in ammatory pro le prior to a lung cancer diagnosis may be associated with mortality. In support of this hypothesis, in ammatory conditions such as chronic bronchitis and emphysema, chronic obstructive pulmonary disease (COPD), interstitial lung disease, and diabetes are associated with increased lung cancer mortality independent of their associations with increased lung cancer risk [10][11][12][13][14][15][16][17][18][19].…”