The Relative Survival Impact of Guideline-Concordant Clinical Staging and Stage-Appropriate Treatment of Potentially Curable Non-Small Cell Lung Cancer

BACKGROUND: Lung cancer management guidelines strive to improve outcomes. Theoretically, thorough staging promotes optimal treatment selection. We examined the association between guideline-concordant invasive mediastinal nodal staging, guideline-concordant treatment, and non-small cell lung cancer survival. RESEARCH QUESTION: What is the current practice of invasive mediastinal nodal staging for patients with lung cancer in a structured multidisciplinary care environment? Is guideline-concordant staging associated with guideline-concordant treatment? How do they relate to survival? STUDY DESIGN AND METHOD: We evaluated patients with nonmetastatic non-small cell lung cancer diagnosed from 2014 through 2019 in the Multidisciplinary Thoracic Oncology Program of the Baptist Cancer Center, Memphis, Tennessee. We examined patterns of mediastinal nodal staging and stage-stratified treatment, grouping patients into cohorts with guideline-concordant staging alone, guideline-concordant treatment alone, both, or neither. We evaluated overall survival with Kaplan-Meier curves and Cox proportional hazards models. RESULTS: Of 882 patients, 456 (52%) received any invasive mediastinal staging. Seventy-four percent received guideline-concordant staging; guideline-discordant staging decreased from 34% in 2014 to 18% in 2019 (P < .0001). Recipients of guideline-concordant staging were more likely to receive guideline-concordant treatment (83% vs 66%; P < .0001). Sixty-one percent received both guideline-concordant invasive mediastinal staging and guideline-concordant treatment; 13% received guideline-concordant staging alone; 17% received guideline-concordant treatment alone; and 9% received neither. Survival was greatest in patients who received both (adjusted hazard ratio [aHR], 0.41; 95% CI, 0.26-0.63), followed by those who received guideline-concordant treatment alone (aHR, 0.60; 95% CI, 0.36-0.99), and those who received guideline-concordant staging alone (aHR, 0.64; 95% CI, 0.37-1.09) compared with neither (P < .0001, log-rank test). INTERPRETATION: Levels of guideline-concordant staging were high, were rising, and were associated with guideline-concordant treatment selection in this multidisciplinary care cohort. Guideline-concordant staging and guideline-concordant treatment were complementary in their association with improved survival, supporting the connection between these two processes and lung cancer outcomes.