Table 3.

Definitions of variables in chart review for patients diagnosed with NSCLC in our single-institutional cohort.

Variable	Definition	Timing of Variable	Included in model	Remarks
Age at NSCLC diagnosis	The age at which patient was first ever diagnosed with NSCLC	At diagnosis	Baseline & extended
Primary NSCLC tumor size	Measurement in centimeters (cm) of largest diameter of primary NSCLC tumor	At diagnosis	Baseline & extended
Overall stage	Clinical stage of patient’s NSCLC
T stage	Clinical T stage	At diagnosis	Baseline & extended
N stage	Clinical N stage	At diagnosis	Baseline & extended
M stage	Clinical M stage	At diagnosis	Baseline & extended
Histologic grading	Histologic grade of primary NSCLC tumor	Follow-up data	N/A	Classified as “unknown” when grade was not determined or data was missing
Histologic subtype	Classification of the histologic subtype of primary NSCLC	Follow-up data	Extended only	Placed into subgroups of adenocarcinoma, squamous cell carcinoma, large cell carcinoma, or other
Surgery	Y/N status of whether patient received surgery for resection of primary NSCLC tumor	Follow-up data	Extended only
Radiation	Y/N status of whether patient received radiation for treatment of primary NSCLC tumor	Follow-up data	Extended only
Chemotherapy	Y/N status of whether patient received chemotherapy for treatment of primary NSCLC tumor	Follow-up data	Extended only
EGFR	Mutational status of EGFR	Follow-up data	N/A
Metastatic Disease	Y/N status of whether patient was ever diagnosed with NSCLC metastatic disease (at time of NSCLC diagnosis or anytime thereafter)	Follow-up data	N/A
Number of extracranial metastatic sites	Number of metastatic sites of disease other than brain	Follow-up data	Extended only
Number of brain metastases	Number of NSCLC brain metastases (diagnosed at time of NSCLC diagnosis or anytime thereafter)	Follow-up data	N/A