Intraoperative Versus Preoperative Diagnosis of Lung Cancer: Differences in Treatments and Patient Outcomes.

OBJECTIVES: Non-small cell lung cancer (NSCLC) is frequently diagnosed during surgical resection. It remains unclear if lack of preoperative tissue diagnosis influences likelihood of receipt of guideline-concordant care or postoperative outcomes. METHODS: A retrospective cohort analysis was completed utilizing the National Cancer Database for patients undergoing lung resection with clinical stage 1 NSCLC from 2004 to 2018. Diagnosis during resection was defined as zero days between diagnosis and definitive lung resection. Patients receiving neoadjuvant therapy were excluded. Subgroup analyses were completed by resection type, including wedge resection. RESULTS: The cohort included 91,328 patients, 33,517 diagnosed during definitive resection and 57,811 diagnosed preoperatively. For patients diagnosed preoperatively, median time from diagnosis to surgery was 42 days (interquartile range 28-63 days). Patients diagnosed intraoperatively had smaller median tumor size (1.7 cm vs. 2.5 cm, P < .01) and were more likely to undergo wedge resection (10,668 [31.8%] vs. 7,617 [13.2%], P < .01). Intraoperative diagnosis resulted in lower likelihood of nodal sampling (27,356 [81.9%] vs. 53,183 [92.4%], P < .01) and nodal upstaging (2,482 [9.7%] vs. 7701 [15.5%], P < .01). Amongst patients with intraoperative diagnoses, those treated via wedge resection were less likely to undergo lymph node sampling (5,515 [52.0%] vs. 5,606 [61.1%], P < .01). Amongst patients with positive lymph nodes, patients diagnosed intraoperatively were less likely to receive adjuvant therapy (1,677 [5.0%] vs. 5,669 [9.8%], P < .01). CONCLUSIONS: Preoperative tissue diagnosis of NSCLC is associated with more frequent lymph node harvest, increased rates of upstaging and receipt of adjuvant therapy. Preoperative workup may contribute to increased rates of guideline-concordant lung cancer care.