Prevalence, Prognostic Implications, and Survival Modulators of Incompletely Resected Non-Small Cell Lung Cancer in the U.S. National Cancer Data Base.

INTRODUCTION: The impact of incomplete lung cancer resection on survival has never been systematically quantified, nor has the value of postoperative adjuvant therapy in this setting been determined.
METHODS: We evaluated lung cancer resections in the National Cancer Data Base from 2004 to 2011 to identify factors associated with margin involvement. We compared the survival of patients with and without positive margins and evaluated the impact of postoperative adjuvant therapy.
RESULTS: Of 112,998 resections performed during the 8 years, 5,335 (4.7%) had positive margins. Patient demographic and clinical factors associated with an increased adjusted OR of incomplete resection included black race (p = 0.006), age-based Medicare insurance (p = 0.006), urban residence (p = 0.01), histologic diagnosis of squamous cell carcinoma, high tumor grade, tumor overlapping more than one lobe, and advanced pathologic stage (p < 0.001 for all clinical factors). Community cancer programs (p = 0.002), institutions with high proportions of underinsured patients (p = 0.01), and institutions with a lower volume of cancer resections (p = 0.006) also had an increased adjusted OR. The crude 5-year survival rates of patients with complete versus incomplete resections were 58.5% versus 33.8% (log-rank p < 0.001). After an incomplete resection, adjuvant chemotherapy was associated with improved 5-year survival across all stages (p < 0.01); radiotherapy was associated with worse survival in patients with stage I disease (p < 0.001).
CONCLUSIONS: Margin involvement significantly impaired survival after lung cancer resection irrespective of stage. Causative institutional and provider practices should be identified to minimize this adverse outcome. Postoperative adjuvant chemotherapy mitigated mortality risk independently of stage, whereas postoperative radiotherapy exacerbated the risk in patients with stage I disease. These findings need validation in prospective trials.