Surgically Managed Clinical Stage IIIA-Clinical N2 Lung Cancer in The Society of Thoracic Surgeons Database

Abstract

Background: The role of surgical resection in patients with clinical stage IIIA-N2 positive (cIIIA-N2) lung cancer is controversial, partly because of the variability in short- and long-term outcomes. The objective of this study was to characterize the management of cIIIA-N2 lung cancer in The Society of Thoracic Surgeons General Thoracic Surgery Database (STS-GTSD).

Methods: The STS-GTSD was queried for patients who underwent operations for cIIIA-N2 lung cancer between 2002 and 2012. A subset of patients aged older than 65 years was linked to Medicare data.

Results: Identified were 3,319 surgically managed, cIIIA-N2 patients, including 1,784 (54%) treated with upfront resection (treatment naïve upfront surgery group, and 1,535 (46%) with induction therapy. A positron emission tomography scan was documented in 93% of patients, and 51% of patients were coded in STS-GTSD as having undergone invasive mediastinal staging. Nodal overstaging (cN2→pN0/N1) was observed in 43% of upfront surgery patients. Lobectomy was performed in 69% of patients and pneumonectomy in 11%. Operative mortality was similar between patients treated with upfront surgery (1.9%) and induction therapy (2.5%, p = .2583). The unadjusted Kaplan-Meier estimate of 5-year survival of cIII-N2 patients treated with induction therapy then resection was 35%.

Conclusions: STS surgeons achieve excellent short- and long-term results treating predominantly lobectomy-amenable cIIIA-N2 lung cancer. However, prevalent overstaging and abstention from induction therapy suggest "overcoding" of false positives on imaging or variable compliance with current guidelines for cIIIA-N2 lung cancer. Efforts are needed to improve clinical stage determination and guideline compliance in the GTSD for this cohort.

Figure 1

Description of Cohorts.

Figure 2

Changes in cIII-N2 over time. The progressive increase in the number of cIII-N2 cases (black line) follows the increase in number of STS-GTDB participants (dashed line). For comparison, the number of patients having surgery for cIII-N2 lung cancer in the National Cancer Database (NCDB) is shown (gray line). The NCDB captures approximately 65% of newly diagnosed lung cancer in the United States

Figure 3

Staging Evaluations. The prevalence (y-axis) of noninvasive (part A) and invasive (part B) staging evaluations are shown for patients in the “full staging cohort” (METHODS) treated with upfront surgery or with induction therapy.

Figure 3

Staging Evaluations. The prevalence (y-axis) of noninvasive (part A) and invasive (part B) staging evaluations are shown for patients in the “full staging cohort” (METHODS) treated with upfront surgery or with induction therapy.

Figure 4

Comparison of operative mortality in the linked subset of patients. 90-day mortality was available for the subset of patients ≥65 that were able to linked to Medicare data. The 90-day mortality is shown across three procedures, stratified according to whether patients were treated with upfront surgery (gray bars) or induction therapy (black bars). For comparison, the 30-day mortality (a composite of STS-GTSD and Medicare data) is shown (white bars).