Real-World Results of Stereotactic Body Radiotherapy for 399 Medically Operable Patients with Stage I Histology-Proven Non-Small Cell Lung Cancer

Abstract

Surgery is the standard treatment for stage I non-small cell lung cancer (NSCLC); however, no clear randomized trial demonstrates its superiority to stereotactic body radiotherapy (SBRT) regarding survival. We aimed to retrospectively evaluate the treatment outcomes of SBRT in operable patients with stage I NSCLC using a large Japanese multi-institutional database to show real-world outcome. Exactly 399 patients (median age 75 years; 262 males and 137 females) with stage I (IA 292, IB 107) histologically proven NSCLC (adenocarcinoma 267, squamous cell carcinoma 96, others 36) treated at 20 institutions were reviewed. SBRT was prescribed at a total dose of 48-70 Gy in 4-10 fractions. The median follow-up period was 38 months. Local progression-free survival rates were 84.2% in all patients and 86.1% in the T1, 78.6% in T2, 89.2% in adenocarcinoma, and 70.5% in squamous cell subgroups. Overall 3-year survival rates were 77.0% in all patients: 90.7% in females, 69.6% in males, and 41.2% in patients with pulmonary interstitial changes. Fatal radiation pneumonitis was observed in two patients, all of whom had pulmonary interstitial changes. This real-world evidence will be useful in shared decision-making for optimal treatment, including SBRT for operable stage I NSCLC, particularly in older patients.

Keywords: operable; real-world evidence; stage I non-small cell lung cancer; stereotactic body radiotherapy.

Figure 1

Local control rate (A) and overall survival rate (B) of all cases. All of the “+” on the curve mean censored cases.

Figure 2

Local control rates according to subgroups arranged by tumor size ((A): maximum diameter less than or equal to 20 mm versus more than 20 mm) (A) and histology ((B): adenocarcinoma versus squamous cell carcinoma). All of the “x” and “+” on the curves mean censored cases.

Figure 3

Overall survival rates according to sex ((A): male versus female), age ((B): less than 75 years old versus more than or equal to 75 years old), tumor size ((C): maximum diameter less than or equal to 20 mm versus more than 20 mm), histology ((D): adenocarcinoma versus squamous cell carcinoma), performance status ((E): 0 versus 1, 2), existence of pulmonary emphysema ((F): negative versus positive), and existence of pulmonary interstitial changes ((G): negative versus positive). All of the “x” and “+” on the curves mean censored cases.

Figure 3

Overall survival rates according to sex ((A): male versus female), age ((B): less than 75 years old versus more than or equal to 75 years old), tumor size ((C): maximum diameter less than or equal to 20 mm versus more than 20 mm), histology ((D): adenocarcinoma versus squamous cell carcinoma), performance status ((E): 0 versus 1, 2), existence of pulmonary emphysema ((F): negative versus positive), and existence of pulmonary interstitial changes ((G): negative versus positive). All of the “x” and “+” on the curves mean censored cases.