Purpose: Approximately 10% of patients with stage I non-small cell lung cancer (NSCLC) are managed without definitive therapy. We therefore investigated whether this rate is similar among veterans cared for by the Veterans Health Administration (VHA), and explored the outcomes and factors associated with under- utilization of these standard of care management strategies.
Methods: The Veterans Affairs (VA) Corporate Data Warehouse (CDW) was queried for all patients diagnosed with NSCLC between 2003 and 2016. Receipt of definitive therapy was determined using VHA cancer registry data, CPT codes and ICD-9/ICD-10 procedure codes within a year after diagnosis. We also captured receipt of chemotherapy as the primary course of treatment, whenever this was the case. Vital status data were assessed using the Kaplan-Meier method.
Results: A total of 19,971 veterans were diagnosed with biopsy-proven clinical stage I NSCLC. The primary treatment for 13,080 (65.5%), 4,889 (24.5%), and 2,002 (10.0%) patients was surgery, RT, or no documented surgery or RT, respectively. The 5-year overall survival for these 3 groups was 53.1%, 19.7%, and 8.9%, respectively. The proportion of patients without documentation of definitive therapy was highest in 2004 at 16.9%, decreasing to 6.3% by 2016. Patients treated at a VA medical center with an on-site radiation oncology service were more likely to receive definitive therapy (chi-square P<0.01). However, this difference was driven by higher utilization of surgery instead of radiation therapy. Among patients without documentation of definitive therapy, 17.4% received systemic chemotherapy as their first reported treatment course.
Conclusion: The proportion of patients without documentation of definitive surgery or RT was similar to previous publications. The rate of no definitive therapy has declined by more than 50% over the past decade, and is coincident with the increased availability of onsite radiotherapy services, as well as minimally invasive thoracic surgery and stereotactic radiotherapy within and outside the VHA. Future investigations of this dataset are likely to increase our understanding about the reasons for treatment delay or avoidance, and its consequences for patients with a highly curable stage I NSCLC.
