A simple risk scoring system for predicting acute exacerbation of interstitial pneumonia after pulmonary resection in lung cancer patients

Objective: Lung cancer patients with interstitial lung diseases (ILDs) who have undergone pulmonary resection often develop acute exacerbation of interstitial pneumonia (AE) in the post-operative period. To predict who is at high risk of AE, we propose a scoring system that evaluates the risk of AE in lung cancer patients with ILDs.

Methods: We derived a score for 30-day risk of AE onset after pulmonary resection in lung cancer patients with ILDs (n = 1,022; outcome: risk of AE) based on seven risk factors for AE that were identified in a previous retrospective multi-institutional cohort study. A logistic regression model was employed to develop a risk prediction model for AE.

Results: A risk score (RS) was derived: 5 × (history of AE) + 4 × (surgical procedures) + 4 × (UIP appearance in CT scan) + 3 × (male sex) + 3 × (preoperative steroid use) + 2 × (elevated serum sialylated carbohydrate antigen, KL-6 level) + 1 × (low vital capacity). The RS was shown to be moderately discriminatory with a c-index of 0.709 and accurate with the Hosmer–Lemeshow goodness-of-fit test (p = 0.907). The patients were classified into three groups: low risk (RS: 0–10; predicted probability <0.1; n = 439), intermediate risk (RS: 11–14; predicted probability 0.1–0.25; n = 559), and high risk (RS: 15–22; predicted probability >0.25; n = 24).

Conclusion: Although further validation and refinement are needed, the risk score can be used in routine clinical practice to identify high risk individuals and to select proper treatment strategies.