Adherence to Posttreatment Surveillance Guidelines in Non-Small Cell Lung Cancer: Retrospective Cohort Study.

Background: Several guidelines recommend posttreatment surveillance for non-small cell lung cancer (NSCLC). However, studies evaluating surveillance patterns often cannot distinguish between imaging ordered for surveillance versus for symptoms suggestive of recurrence. Moreover, early recurrences and other competing events hamper efforts to determine true surveillance rates because of wide variability in reported guideline adherence in clinical practice. Leveraging comprehensive Veterans Health Administration data, we developed a novel competing risks framework to describe the patterns and predictors of NSCLC imaging surveillance.

Objective: This study aims to examine posttreatment surveillance to estimate the true surveillance rates and predictors of guideline-concordant care in patients with early-stage NSCLC.

Methods: The study cohort comprised veterans who were treated for stage 1 to 3 NSCLC between 2008 and 2016 and who survived for ≥6 months. Clinical documents and radiology reports were abstracted for image indication and clinical information. We estimated the cumulative probability of receiving guideline-concordant surveillance, defined as chest computed tomography imaging within 4 to 9 months after treatment, accounting for competing risks and censoring. Multivariable cause-specific Cox regression was used to estimate associations between patient factors and guideline-concordant surveillance, with adjustments made for multiple comparisons.

Results: The cohort consisted of 1888 patients. The mean age of the analysis cohort was 66.4 (SD 7.9) years; 95.9% (1811/1888) of the patients were male, 71.1% (1342/1888) of the patients were White, and 43.1% (814/1888) were married. Of the 1888 patients, 57% (n=1076) presented with stage 1 disease, and the most common treatment modality was surgery alone (n=1068, 56.6%). The most common type of imaging performed during the initial 120- to 270-day window was chest computed tomography (1460/3278, 44.5%). Chest X-rays accounted for 36.3% (1190/3278) of all imaging performed, while the remaining 11.8% (386/3278) and 7.4% (242/3278) were positron emission tomography scans or other imaging modalities, respectively. Compared to the years 2008 to 2010, patients treated for NSCLC from 2014 to 2016 had a significantly higher likelihood of receiving guideline-concordant surveillance (hazard ratio 1.42, P<.001).

Conclusions: In this unique application of a competing risks framework, the rate of guideline-concordant surveillance in this national cohort was lower than that reported in many previous studies. This finding highlights a potentially substantial gap in surveillance among eligible, asymptomatic lung cancer survivors. More strategies are needed to measure the true rate of guideline-concordant surveillance, along with education and advocacy to ensure guideline-concordant care.