ANÁLISIS DE N2 INSOSPECHADO EN PACIENTES CON CÁNCER DE PULMÓN DE CÉLULAS NO PEQUEÑAS ESTADIO CLÍNICO IA: IMPACTO DE LA ESTADIFICACIÓN ACTUAL Y LOCALIZACIÓN DEL TUMOR

Abstract

Background: Accurate staging in non small cell lung cancer (NSCLC) is essential to define the appropriate treatment, primary

being the affection of mediastinal lymph node groups (N2).

Objective: To determine the incidence of unexpected N2 compromise, according to the new subdivision of T1 tumors in T1a and T1b, and lobe tumor location, in patients with clinical stage IA.

Setting: Thoracic Surgery Department, Hospital Británico de Buenos Aires

Design: Restrospective, cohort

Population: Patients operated on with curative intent, clinical Stage IA, with final histological diagnosis of NSCLC between 2000

and 2010.

Methods: Incidence of unsuspected N2 disease was analyzed according to the tumor size (up to 20 mm, more than 20 to 30 mm), side, lobe location (upper and middle, lower lobes), sex, age, tumor type and smoking history.

Outcome measures: Student’s t test, Chi square and Fisher.

Results: 115 patients were included (men, 54.7%; mean age, 61 years, range 44-85). Average nodule size was 17.4 mm (6-30); 57.3% patients had nodules up to 20 mm (T1a) and 42.7% between 20 mm and 30 mm (T1b). Histology showed 82.6% adenocar- cinoma. Lobectomy was performed in 101 patients (87.8%). Unsuspected N2 compromise was present in 9 (7.8%) patients. When divided into subgroups, 3 (4.5%) were T1a and 6 (12.2%) were T1b (p=0.14). All of the N2 were observed in tumors located in the upper or the middle lobes (9/80, 11.2%, p= 0.03). No nodules smaller than 10 mm showed N2 disease.