The Ratio KL-6 to SLX in Serum for Prediction of the Occurrence of Drug-Induced Interstitial Lung Disease in Lung Cancer Patients with Idiopathic Interstitial Pneumonias Receiving Chemotherapy.

We retrospectively evaluated whether the ratio KL-6 to SLX in serum (K/S ratio) before chemotherapy was a predictor for the occurrence of drug-induced interstitial lung disease (D-ILD) in lung cancer patients with idiopathic interstitial pneumonias (IIPs). D-ILD occurred in 8 of 20 IIPs-positive cases and in 14 of 100 IIPs-negative cases (40 vs. 14%, p = .015). In IIPs-positive cases, the high K/S ratio (>20) before first-line chemotherapy had a tendency to increase the risk of D-ILD (p = .085). Serum K/S ratio may be a useful predictor for the occurrence of D-ILD in lung cancer patients with IIPs.