Brain metastases in non-small cell lung cancer patients on epidermal growth factor receptor tyrosine kinase inhibitors: symptom and economic burden

Objective: This study describes the symptom and economic burden associated with brain metastases (BM) in patients with non-small cell lung cancer (NSCLC) receiving epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (EGFR-TKIs).

Methods: This retrospective study included adults with ≥2 medical claims, within 90 days, for lung cancer and ≥1 administration of EGFR-TKIs. Based on ICD-9 codes, patients were stratified into cohorts by type of metastases (BM, other metastases [OM], or no metastases [NM]), and by when the metastasis diagnosis occurred (synchronous or asynchronous).

Results: The population (synchronous BM [SBM]?=?24, synchronous OM [SOM]?=?23, asynchronous BM [ASBM]?=?15, asynchronous OM [ASOM]?=?49, NM?=?85) was mostly female (57%), average age 69 years (SD?=?11). SBM patients experienced more fatigue and nausea/vomiting compared with SOM and NM patients and more headaches and loss of appetite than NM patients. ASBM was associated with more fatigue, nausea/vomiting, headaches, pain/numbness, altered mental status, and seizures than NM, and more headaches and pain/numbness than ASOM. SBM patients experienced a greater increase in per-member-per-month all-cause total healthcare costs after diagnosis ($20,301) vs SOM ($9,131, p?=?.001) and NM ($2,493, p?=?.001). ASBM’s cost increase between baseline and follow-up ($7,867) did not differ from ASOM’s ($4,947, p?=?.195); both were larger than NM ($2,493, p?=?.001 and p?=?.009, respectively).

Limitations: EGFR mutation status was inferred based on EGFR-TKI treatment, not by molecular testing. Patients were from US commercial insurance plans; results may not be generalizable to other populations.

Conclusions: Among patients with EGFR-TKI-treated NSCLC, patients with BM experienced more symptoms and, when diagnosed synchronously, had significant increases in total medical costs vs patients with OM and NM. Therapeutic options with central nervous system activity may offer advantages in symptomatology and costs in EGFR-mutated patients with BM.