Treatment outcome of patients with unresectable stage III non-small cell lung cancer and interstitial pneumonia

Treatment outcomes of patients with stage III non-small cell lung cancer and interstitial lung diseases receiving intensity-modulated radiation therapy: A single-center experience of 85 cases

OBJECTIVES

Whether curative-intent radiotherapy could be safely applied to lung cancer patients with interstitial lung diseases (ILD) remains unclear. We aim to evaluate radiation induced lung toxicities (RILTs) and the efficacy of intensity-modulated radiotherapy (IMRT) in these patients. ILD is characterized by inflammation or fibrosis in the interstitial tissue of the lung.

MATERIALS AND METHODS

Stage III non-small cell lung cancer (NSCLC) and ILD patients treated with curative-intent IMRT between 2010 and 2019 were retrospectively reviewed. Pre-radiation computed tomography (CT) was scored according to a thin-section CT scoring system for idiopathic pulmonary fibrosis.

RESULTS

A total of 85 of 1261 stage III NSCLC patients were found with ILD. Seventeen (20%) of them developed G3+ (greater than or equal to grade 3) RILTs. The incidence abruptly dropped to 11.1%, 3.8%, and 0% for patients with honeycombing score ≤1, V20 <20%, or both, respectively. Multivariate analysis showed that honeycombing score >1 and V20 ≥20% were independently associated with higher risk of G3+ RILTs. The median overall survival (OS) and progression-free survival (PFS) were 14.0 months and 7.4 months in the whole group, whereas 26.5 months and 10.6 months in the low-risk group (patients with honeycombing score <1 and V20 <20%). In the univariate analysis for overall survival, G3+ RILTs were evaluated as risk factors (p = 0.026) and low-risk group as the only protective factor (p = 0.063). In the multivariate analysis, G3+ RILTs were the only independent risk factor for OS.

CONCLUSION

Honeycombing score >1 and V20 ≥20% were associated with high incidence of RILTs. However, patients with low risk might benefit from IMRT with acceptable toxicities and durable OS.

Risk factors for acute exacerbation in lung cancer complicated by interstitial lung disease with slight reticular shadows

BACKGROUND

The risk of cancer treatment-related acute exacerbation (AE) in patients with lung cancer and mild interstitial lung disease (ILD) on imaging, classified as indeterminate for usual interstitial pneumonia (UIP), has not previously been clarified.

METHODS

We retrospectively reviewed the clinical records of 27 patients with lung cancer and ILD who were diagnosed and treated from April 2016 to March 2021.

RESULTS

Among the 27 patients, 21 were classified as indeterminate for UIP and six as UIP/probable UIP; furthermore, 10 (46.6%) and three (50%) patients from each group, respectively, developed treatment-related AEs. No significant difference was observed regarding the incidence of AEs between the two groups. However, significantly more patients in the AE group received immune checkpoint inhibitors (ICIs) compared to the non-AE group (p = 0.021). Multivariate analysis revealed that the use of ICIs was a significant independent risk factor for treatment-related AEs.

CONCLUSIONS

Lung cancer patients with mild ILD suggestive of indeterminate for UIP and UIP patterns are at an increased risk for treatment-related AEs. Furthermore, ICI use is an independent risk factor for AEs in patients with lung cancer complicated by ILD, and ICIs should be used with great caution.