Pleural contact decreases survival in clinical T1N0M0 lung cancer patients undergoing SBRT

Radiother Oncol. 2019 May:134:191-198. doi: 10.1016/j.radonc.2019.02.005. Epub 2019 Feb 26.

Abstract

Background: Clinical staging, as used for patients treated with stereotactic body radiotherapy (SBRT) for early-stage lung cancer, inadequately accounts for pleural invasion, which is a pathologic criteria. Considering the current situation, we analyzed effects of relationships between tumors and the pleura on treatment outcomes of SBRT for early-stage lung cancer.

Materials and methods: Among consecutive patients treated with SBRT between 2006 and 2017, we retrospectively identified non-small cell lung cancer patients with primary tumor diameters ≤4 cm and N0M0. The relationships between tumors and the pleura were investigated. The effects of these findings on treatment outcomes were analyzed.

Results: We identified 386 patients which met the inclusion criteria. Among these patients, 323 patients were with tumors of 0.1-3.0 cm (T1-size), and 63 patients were with tumors of 3.1-4.0 cm (T2a-size). Among patients with T1-size tumors, 120, 134, and 23 had findings of pleural contact, pleural indentation, and pleural thickening, respectively. When we divided T1-size patients into 2 groups based on pleural contact (contact- or contact+), the 3-year cause-specific mortality and overall survival in patients with T1-size & contact+ were significantly worse than those in patients with T1-size & contact- (17.6% (95% confidence interval (CI), 10.7-25.9%) vs. 6.6% (95% CI, 3.5-11.1%), p < 0.01), and 58.2% (95% CI, 47.6-67.5%) vs. 77.6% (95% CI, 70.5-83.2%), p < 0.01). Local recurrence, regional recurrence, pleural cavity recurrence, and distant metastasis were associated with worse cause-specific mortality and overall survival. On multivariate analysis, pleural contact was associated with cause-specific mortality (hazard ratio (HR), 1.96; 95% CI, 1.09-3.52; p = 0.03) and overall survival (HR, 1.59; 95% CI, 1.08-2.34; p = 0.02).

Conclusion: Pleural contact in clinical T1N0M0 lung cancer patients was associated with significantly worse survivals.

Keywords: Clinical T stage; Pleural contact; Pleural invasion; SBRT.

Publication types

  • Research Support, Non-U.S. Gov't

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*
  • Female
  • Humans
  • Lung Neoplasms / mortality
  • Lung Neoplasms / pathology*
  • Lung Neoplasms / radiotherapy*
  • Male
  • Middle Aged
  • Neoplasm Recurrence, Local / pathology
  • Neoplasm Staging
  • Pleura / pathology*
  • Proportional Hazards Models
  • Radiosurgery / methods
  • Radiosurgery / mortality
  • Retrospective Studies
  • Treatment Outcome