C.K. Bedrosian1, E.S. Kawaguchi3, L. Ding4, G. Rosenberg2, T. Harano2, S. Wightman2, S. Atay2, A.W. Kim2, G. Woodard5, B.V. Udelsman2 1University Of Southern California, Keck School Of Medicine, Los Angeles, CA, USA 2University Of Southern California, Surgery, Los Angeles, CA, USA 3University Of Southern California, Population And Public Health Sciences, Los Angeles, CA, USA 4University Of Southern California, Clinical And Translational Science Institute, Los Angeles, CA, USA 5Yale University School Of Medicine, Surgery, New Haven, CT, USA
Introduction: Treatment guidelines for non-small cell lung cancer (NSCLC) recommend systemic therapy for patients with tumors >5cm even in the absence of metastatic or nodal disease. We hypothesized that systemic therapy for patients with T3N0M0 NSCLC would be associated with a survival benefit but underutilized due to clinician decision rather than patient status (e.g., comorbidities, socioeconomic factors).
Methods: Patients with surgically resected NSCLC tumors >5 and ≤7cm diagnosed between 2010 and 2019 were selected from the National Cancer Database. Exclusion factors were metastatic disease, nodal involvement, missing follow-up data, ≥R1 resection, or previous cancer. Tumor size was based on the resected pathological specimen or radiological imagining in a neoadjuvant setting. Patients who received systemic therapy (chemotherapy, immunotherapy, or targeted therapy) were compared to those who did not receive systemic therapy. Covariates included sociodemographic factors, Charlson Comorbidity Index (CCI), surgical procedures, facility type, and tumor characteristics. Survival was compared using a Kaplan-Meier method and a Cox proportional hazard model. Reasons for not including systemic therapy in the treatment plans were recorded.
Results: Of 8,274 identified patients, 3,787 (45.8%) received systemic therapy. Among those patients, 3,075 (37.2%) received adjuvant therapy, 540 (6.5%) neoadjuvant therapy, 101 (1.2%) received systemic therapy before and after surgical resection, and 71 (0.9%) patients had an unrecorded order. Systemic therapy recipients tended to be younger (64.6 vs. 69.5; p<0.001), female (45.1% vs 42.1%; p=0.01), have private insurance (37.4% vs. 24.4%; p<0.001), be treated at an academic center (39.2% vs. 35.7%; p<0.001), have a CCI of 0 (54.0% vs. 50.5%; p<0.001), and have adenocarcinoma (47.5% vs. 40.7%; p<0.001). The 5-year survival was 67.4% with systemic therapy compared to 52.7% with surgery only. Using a multivariable Cox regression, systemic therapy remained associated with a decreased mortality risk (HR 0.73, 95%-Confidence Interval 0.68-0.78; p<0.001). The primary reason for a lack of systemic therapy treatment for 3,368 (75.1%) patients was “not planned as part of treatment”, followed by “recommended but declined by patients or caregivers” for 742 patients (16.5%) (Table).
Conclusion: Although systemic therapy for T3N0M0 NSCLC is associated with increased survival, it is severely underutilized. Clinicians should be aware of this phenomenon and advocate accordingly.