Outcomes in stage I non-small cell lung cancer following the introduction of stereotactic body radiotherapy in Alberta - A population-based study.
OBJECTIVE
To review outcomes of patients with stage I non-small cell lung cancer (NSCLC) following the introduction of stereotactic body radiation therapy (SBRT).


METHODS
SBRT cases were linked to the cancer registry database along with clinical, treatment and health service parameters for n=2146 cases of stage I NSCLC diagnosed between 2005 and 2011. The pre-diagnosis Aggregated Clinical Risk Grouping score (ACRG3) was used as a proxy for pre-treatment patient comorbidity. A Cox regression model and the concordance statistic (C-statistic) were used to examine variables predicted for overall survival (OS).


RESULTS
The SBRT utilization rate increased annually with superior OS to conventional RT (median survival [MS] of 39.4 VS. 23.5months, P<0.001) despite higher ACRG3 scores. Surgical patients were younger, had lower ACRG3, achieving MS of 69.6months. Regression analysis indicated both Surgery (hazard ratio [HR]=0.23, 95% CI: 0.18-0.28) and SBRT (HR=0.33, 95% CI: 0.21-0.51) remained most strongly associated with OS. ACRG3 (HR=0.79, P<0.001) and age (HR=0.83, P=0.03) were independently associated with OS. The OS model was associated with the C-statistic at 0.86, 95% CI: 0.81-0.90.


CONCLUSIONS
In stage I NSCLC patients treated with surgery have the best survival. SBRT demonstrates improved OS compared to conventional RT. C-statistic result demonstrates discrimination of treatment selection factors on OS.
Central Alberta Cancer Centre, Red Deer, Canada; Department of Oncology, University of Alberta, Canada; Department of Oncology, University of Calgary, Canada. Electronic address: hongwei.liu@albertahealthservices.ca.
Hong-Wei
HW
Liu
Cross Cancer Institute, Edmonton, Canada; Department of Oncology, University of Alberta, Canada.
Zsolt
Z
Gabos
Cross Cancer Institute, Edmonton, Canada; Department of Oncology, University of Alberta, Canada.
Sunita
S
Ghosh
Data Integration, Measurement & Reporting, Alberta Health Services, Canada.
Barbara
B
Roberts
Tom Baker Cancer Centre, Calgary, Canada; Department of Oncology, University of Calgary, Canada.
Harold
H
Lau
Tom Baker Cancer Centre, Calgary, Canada; Department of Oncology, University of Calgary, Canada.
Marc
M
Kerba
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000416:Alberta / Q000453:epidemiology; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D016634:Radiosurgery / Q000379:methods / Q000706:statistics & numerical data*; D012042:Registries; D016896:Treatment Outcome
Concordance statistic; Lung SBRT; Overall survival; Population study; Stage I NSCLC