Background: Guidelines recommend mediastinal lymph node sampling as the first invasive test in patients with suspected lung cancer with mediastinal lymphadenopathy without distant metastases, but there are no comparative effectiveness studies on how test sequencing affects outcomes. The objective was to compare practice patterns and outcomes of diagnostic strategies in patients with lung cancer.
Methods: The study included a retrospective cohort of 15,316 patients with lung cancer with regional spread without distant metastases in the Surveillance, Epidemiology, and End Results or Texas Cancer Registry Medicare-linked databases. If the first invasive test involved mediastinal sampling, patients were classified as receiving guideline-consistent care; otherwise, they were classified as receiving guideline-inconsistent care. We used propensity matching to compare the number of tests performed and multivariate logistic regression to compare the frequency of complications.
Results: Twenty-one percent of patients had guideline-consistent diagnostic evaluations. Among patients with non-small cell lung cancer, 44% never had mediastinal sampling. Patients who had guideline-consistent care required fewer tests than those with guideline-inconsistent care (P < .0001), including thoracotomies (49% vs 80%, P < .001) and CT image-guided biopsies (9% vs 63%, P < .001), although they had more transbronchial needle aspirations (37% vs 4%, P < .001). The consequence was that patients with guideline-consistent care had fewer pneumothoraxes (4.8% vs 25.6%, P < .0001), chest tubes (0.7% vs 4.9%, P < .001), hemorrhages (5.4% vs 10.6%, P < .001), and respiratory failure events (5.3% vs 10.5%, P < .001).
Conclusions: Guideline-consistent care with mediastinal sampling first resulted in fewer tests and complications. We found three quality gaps: failure to sample the mediastinum first, failure to sample the mediastinum at all in patients with non-small cell lung cancer, and overuse of thoracotomy.