Dual intervention to improve pathologic staging of resectable lung cancer

Abstract

Background: 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.

Methods: 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.

Results: 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.

Conclusions: 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.

Keywords: 10; ACOSOG; American College of Surgeons Oncology Group; Chemo; ECOG; ESTS; Eastern Cooperative Oncology Group; European Society of Thoracic Surgeons; IQR; NCCN; NSCLC; National Comprehensive Cancer Network; PET/CT; SD; TNM; XRT; ambiguous pathologic nodal stage because of no examination of lymph nodes; interquartile range; non–small cell lung cancer; pN1; pN2; pNX; pathologic N1; pathologic N2; positron emission tomography/computed tomography; postoperative adjuvant chemotherapy; postoperative adjuvant radiation therapy; standard deviation; tumor, node, metastasis staging system.