Effect of Interstitial Lung Abnormality on Concurrent Chemoradiotherapy-treated Stage III Non-small Cell Lung Cancer Patients.

Background/aim: Pre-treatment interstitial lung abnormality (ILA) is associated with post-cancer treatment adverse events and high mortality rate in lung cancer patients. This study aimed to assess whether ILA affects the survival and development of symptomatic radiation pneumonitis (RP) in unresectable stage III non-small cell lung cancer (NSCLC) patients who had undergone definitive concurrent chemoradiotherapy (CCRT).

Patients And Methods: Data of stage III NSCLC patients who underwent definitive CCRT between January 2010 and November 2017 were retrospectively collected. Univariate and multivariate regression analyses were performed to evaluate the risk factors for symptomatic RP. The association between pre-treatment ILA and survival was assessed using Kaplan-Meier analysis with log-rank test and Cox proportional hazards regression.

Results: This study included 201 patients (188 men) of a mean age of 64.7±7.3 years. Pre-treatment ILA and fibrotic ILA were observed in 21.9% and 12.9% of the patients, respectively. Symptomatic RP (grade ≥2) occurred in 13.5% of the patients. Fibrotic ILA was a significant risk factor for grade ≥2 RP and grade ≥3 RP (p=0.004 and 0.033, respectively). The survival rate was significantly poorer in patients with fibrotic ILA than in those without ILA. Cox proportional hazards regression revealed that fibrotic ILA was an independent risk factor for mortality (p<0.001).

Conclusion: Pre-treatment fibrotic ILA is significantly associated with symptomatic RP and poor survival in unresectable stage III NSCLC patients who have undergone definitive CCRT. CCRT should be cautiously performed in patients presenting pre-treatment fibrotic ILA to prevent adverse outcomes.