RÉSUMÉ
INTRODUCTION: Median age at diagnosis of lung cancer is 70 years. Its presentation in patients 40 or younger is uncommon and it has been proposed that maybe it is a different disease due to its clinical characteristics and genetic makeup. There are a limited number of studies in this population and they report different clinic-pathological characteristics in comparison with older patients. METHODS: We described the incidence of lung cancer patients diagnosed at age 40 or younger at the Instituto Nacional de Enfermedades Neoplasicas (INEN), Lima-Peru; from 2009 to 2017 and evaluated the characteristic of NSCLC. Epidemiologic and clinic-pathological data was collected from clinical files. Analysis was carried out using SPSSvs19 software. RESULTS: We identified 3823 patients with lung cancer seen at INEN during the study period. Among these, 166 (4.3%) patients were 40 years or younger, and 137/166 (82.5%) were NSCLC. Median age at diagnosis was 36 years (range 14-40 years) and 59.1% of patients were female. A smoking history was present in 14.4% of patients. Frequent symptoms at diagnosis were cough (62.0%), chest pain (51.8%) and dyspnea (40.9%). Adenocarcinoma was the most common histological type (63.3%). Most patients had advanced disease at diagnosis (84.7%). The median overall survival was 8.2 months. CONCLUSIONS: The proportion of young patients with lung cancer in our population is higher than that reported in the most recent literature. Lung cancer in the young is mostly sporadic, more frequent in women, usually adenocarcinoma type and it presents with advanced disease, resulting in a very poor survival.