Five-year Long-term Outcomes of Stereotactic Body Radiation Therapy for Operable Versus Medically Inoperable Stage I Non-small-cell Lung Cancer: Analysis by Operability, Fractionation Regimen, Tumor Size, and Tumor Location

Clin Lung Cancer. 2019 Jan;20(1):e63-e71. doi: 10.1016/j.cllc.2018.09.004. Epub 2018 Sep 20.

Abstract

Background: Stereotactic body radiation therapy (SBRT) is standard for medically inoperable stage I non-small-cell lung cancer (NSCLC) and is emerging as a surgical alternative in operable patients. However, limited long-term outcomes data exist, particularly according to operability. We hypothesized long-term local control (LC) and cancer-specific survival (CSS) would not differ by fractionation schedule, tumor size or location, or operability status, but overall survival (OS) would be higher for operable patients.

Patients and methods: All consecutive patients with stage I (cT1-2aN0M0) NSCLC treated with SBRT from June 2009 to July 2013 were assessed. Thoracic surgeon evaluation determined operability. Local failure was defined as growth following initial tumor shrinkage or progression on consecutive scans. LC, CSS, and OS were calculated using Cox proportional hazards regression.

Results: A total of 186 patients (204 lesions) were analyzed. Most patients were inoperable (82%) with Eastern Cooperative Oncology Group performance status of 1 (59%) or 2 (26%). All lesions received biological effective doses ≥ 100 Gy most commonly (94%) in 3 to 5 fractions. The median follow-up was 4.0 years. LC at 2 and 5 years were 95.6% (95% confidence interval, 92%-99%) and 93.7% (95% confidence interval, 90%-98%), respectively. Compared with operable patients, inoperable patients did not have significant differences in 5-year LC (93.1% vs. 96.7%; P = .49), nodal failure (31.4% vs. 11.0%; P = .12), distant failure (12.2% vs. 10.4%; P = .98), or CSS (80.6% vs. 91.0%; P = .45) but trended towards worse OS (34.2% vs. 45.3%; P = .068). Tumor size, location, and fractionation did not significantly influence outcomes.

Conclusions: SBRT has excellent, durable LC and CSS rates for early-stage NSCLC, although inoperable patients had somewhat lower OS than operable patients, likely owing to greater comorbidities.

Keywords: Local control; NSCLC; SABR; SBRT; Stereotactic ablative radiotherapy.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Carcinoma, Non-Small-Cell Lung / mortality
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Carcinoma, Non-Small-Cell Lung / radiotherapy*
  • Dose Fractionation, Radiation
  • Female
  • Follow-Up Studies
  • Humans
  • Lung Neoplasms / mortality
  • Lung Neoplasms / pathology
  • Lung Neoplasms / radiotherapy*
  • Male
  • Middle Aged
  • Neoplasm Staging
  • Radiosurgery*
  • Survival Analysis
  • Treatment Outcome
  • Tumor Burden