Carcinoma

Adenocarcinoma

Surgery

Lung cancer

Radiology

Lesion

Alternative medicine

Mediastinoscopy

Internal medicine

Oncology

Medicine

Nuclear medicine

Occult

Cancer

Lung

Positron emission tomography

Mediastinum

Pathology

Journal of Thoracic Oncology

Accuracy in lung staging is essential for the management of lung cancer. Positron emission tomography (PET-CT) allows us to identify occult disease and avoid unnecessary surgeries in patients with extended disease. In recent years, the histological distribution has varied in non-small cell lung carcinomas. Historically, squamous carcinoma had been more frequent, but in recent years adenocarcinoma has been progressively increasing its incidence. We have retrospectively reviewed all patients that underwent surgery after cN0-N1 staging. Staging studying consisted in chest computed tomography, PET-CT and fiberbronchoscopy. In case of increased mediastinal PET-CT uptake, hiliar lesion, N1 involvement or tumour greater than 3 cm an endobronchial ultrasound (EBUS) and/or mediastinoscopy was performed. Our aim was to study if this histological change has increased our occult pN2 in cN0-N1 patients Between January 2010 and March 2016, 484 patients were consecutively operated. 112 patients (92 men and 20 women) had hilar or mediastinal homolateral involvement. The average age was 63.62 years ± 8.99. The initial nodal involvement was cN0 73.2% (82 patients), cN1 21.4% (24p) and ycN0 after neoadjuvant therapy 5.4% (6p). The following data were analysed: age of the patient, sex, histology of the lesion, staging, location, type of resection performed, laterality and nodal involvement. Subsequently, the statistical analysis was performed with SPSS 25. The most frequent histology was adenocarcinoma in 256 patients (52.89%), squamous carcinoma in 198 (40.9%), other 30 (6.1%). 25.78% adenocarcinoma (66p) and 23.23% squamous carcinoma (46p) presented nodal involvement. By zones, N1 and N2 involvement was 11.71% (30p) and 14.06% (36p) in adenocarcinoma group. 16.16% (32p) and 7.07% (14p) in squamous group (p <0.05). The odds ratio for occult pN2 was 1,988 in adenocarcinoma (p<0.05). PET-CT underestimates the presence of unexpected pN2 in adenocarcinoma lung cancer. Further mediastinal investigations may be necessary in these patients prior to surgical resection

P2.13-01 PET-CT Underestimates Unexpected pN2 in Lung Adenocarcinoma