Dual Intervention to Improve Pathologic Staging of Resectable Lung Cancer

Abstract

Detection of lymph node metastasis is of immense prognostic value in patients with resectable non-small cell lung cancer (NSCLC), but routine pathologic nodal staging is suboptimal. To determine the impact on the rate of detection of nodal metastasis, we tested dual intervention with a prelabeled lymph node specimen collection kit to improve intraoperative node dissection and a fastidious gross dissection of the lung resection specimen for intrapulmonary lymph nodes. We matched dual-intervention cases with controls staged using standard surgical specimen collection and pathologic examination protocols. Controls were hierarchically matched for extent of resection, laterality, surgeon, pathologist, and T stage. All statistical comparisons were made with exact conditional logistic regression, to account for the matched case-control design. One hundred dual-intervention cases were matched with 100 controls. The dual interventions resulted in approximately a 3-fold increase in the number of lymph nodes examined and the number of lymph nodes with metastasis detected; they also increased the proportion of patients with lymph node metastasis from 21% to 35% (p= 0.02). There were strong trends toward higher aggregate stage distribution, and eligibility for postoperative adjuvant chemotherapy in the dual-intervention cases. The combination of interventions improved the thoroughness and accuracy of pathologic nodal staging. A prospective randomized trial to test the survival impact of the dual interventions is warranted.