Impact Of Underlying Pulmonary Diseases On Treatment Outcomes In Early-Stage Non-Small Cell Lung Cancer Treated With Definitive Radiotherapy

Abstract

Purpose

Current guidelines recommend definitive radiotherapy for patients with medically inoperable early-stage non-small cell lung cancer (NSCLC). However, the impact of underlying pulmonary diseases on survival in those patients remains unclear.

Methods

We retrospectively reviewed the medical records of 234 patients with stage I-II NSCLC treated with definitive radiotherapy alone at Samsung Medical Center between January 2010 and October 2017. We compared survival outcomes according to the presence of underlying pulmonary diseases, including chronic obstructive pulmonary disease (COPD), combined pulmonary fibrosis and emphysema (CPFE), and idiopathic pulmonary fibrosis (IPF). The control group in this study was stage I-II NSCLC patients who were non-COPD, non-CPFE, and non-IPF.

Results

The median follow-up duration was 17 (range, 1–92) months. The median survival times of the control, COPD, CPFE, and IPF groups were 32, 49, 17, and 12 months, respectively (P<0.001). In a Cox proportional hazards analysis for factors associated with overall survival, patients with COPD showed a similar risk of death (adjusted hazard ratio [HR], 1.306; 95% confidence interval [CI], 0.723–2.358; P=0.376) compared to that of the control group, while patients with CPFE (adjusted HR, 3.382; 95% CI, 1.472–7.769; P=0.004) and IPF (adjusted HR, 4.061; 95% CI, 1.963–8.403; P<0.001) showed an increased risk of death.

Conclusion

Definitive radiotherapy may be a tolerable treatment for early-stage NSCLC with COPD. However, poor survival in early-stage NSCLC patients with IPF or CPFE requires further study to identify and develop patient selection criteria as well as an optimal radiotherapy modality.

Keywords:

• non-small cell lung cancer
• pulmonary disease
• radiotherapy
• survival

Acknowledgments

This work was supported by the National Research Foundation of Korea (NRF), grant funded by the Ministry of Science and ICT (NRF-2017M2A2A7A02018569).

Abbreviations

3DCRT, 3-dimensional conformal RT; BED₁₀, biologically equivalent doses at α/β of 10 Gy; CI, confidence interval; COPD, chronic obstructive pulmonary disease; CPFE, combined pulmonary fibrosis and emphysema; CTV, clinical target volume; DL_CO, diffusing capacity of the lung for carbon monoxide; EBUS-TBNA, endobronchial ultrasound-guided transbronchial needle aspiration; FEV₁, forced expiratory volume in one second; FVC, forced vital capacity; GOLD, Global Initiative for Chronic Obstructive Lung Disease; GTV, gross tumor volume; HRCT, high-resolution CT; HR, hazard ratio; IMRT, intensity-modulated RT; IPF, idiopathic pulmonary fibrosis; NSCLC, non-small cell lung cancer; OS, overall survival; PET-CT, 18F-fluorodeoxyglucose positron emission tomography with CT; PTV, planning target volume; SBRT, stereotactic body radiation therapy.

Ethics Approval And Consent To Participate

This study was approved by the ethics committee of Samsung Medical Center (no. 2018-08-108) and informed consent was waived due to the retrospective nature.

Availability Of Data And Material

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Disclosure

The authors report no conflicts of interest in this work.