Article Abstract

Long term and disease-free survival following surgical resection of occult N2 lung cancer

Authors: Bilal H. Kirmani, Sara Volpi, Giuseppe Aresu, Adam Peryt, Thida Win, Aman S. Coonar


Background: Despite systematic investigation with computed tomography (CT), positron emission tomography (PET)/CT, CT or magnetic resonance imaging (MRI) brain imaging and supplementary investigation using endobronchial ultrasound guided biopsy (EBUS), endo-oesophageal ultrasound guided biopsy (EUS), fine needle aspiration (FNA), mediastinoscopy or mediastinotomy, there is an approximately 10% rate of occult N2 disease identified at pathological staging. It has been hypothesised that such occult disease, too small or inactive to be identified during pre-operative multi-modality staging, may represent low volume disease that may have equivalent survival to patients with similar stage at clinical, pre-operative assessment. We compared the long-term survival and disease-free survival of patients with the same clinical TNM stage with and without occult N2 disease.
Methods: We retrospectively analysed a database that prospectively captured information on all patients assessed and treated for lung cancer in our surgical unit. We reviewed data on patients who underwent lung cancer surgery with curative intent between January 2006 and August 2010.
Results: A total of 312 lung cancer resections were performed [mean age 68 (range, 42–86) years old and male:female ratio 1.14:1]. Occult N2 disease was identified in 28 (8.7%) of 312 patients. There was no difference in the rate of N2 disease for different tumour histological types. Five-year survival with occult N2 disease was 35.8% vs. 62.5% without. Median survival was 34 months with occult N2 disease vs. 84 months without.
Conclusions: With contemporary staging techniques, so-called occult N2 disease, even with low volume and PET non-avid disease, does not have an indolent course and should still be considered a risk factor for poorer prognosis.