e17508 Background: Lung cancer remains uncommon among young adults but it causes great loss of life expectancy in this age group. The definition of young age varies in the published studies from 40 to 50 years of age. Methods: Our aim was to assess whether patients diagnosed at young ages have unique clinicopathological and prognostic characteristics. We retrospectively reviewed records of patients aged 45 or younger who were treated for primary lung cancer at a large tertiary center between June 2003 and June 2011. Results: 2,651 patients with lung cancer were screened of whom 73 (2.8%) were aged ≤45. The male-to-female ratio was 1.6:1 and the median age at diagnosis was 42. 89% of patients were smokers. Performance status (PS) was 0, 1 and 2 in 61%, 29% and 10% of patients, respectively. The most common histological types were adenocarcinoma (47%), small-cell lung cancer (SCLC) (18%) and squamous cell carcinoma (18%). The median time elapsing between beginning of symptoms and diagnosis was 3 months. Chronic hepatitis B or C was mentioned in the medical history of 5/13 (38%) SCLC patients, whereas it was present in 4/60 NSCLC patients under 45 (p=0.008) and in 16/518 SCLC patients over the age of 45 (p<0.0001). Patients were diagnosed with stages I, II, III and IV in 2 (3%), 11 (18%), 13 (22%) and 34 (57%) of NSCLC cases, respectively, whereas 7 of 13 (54%) SCLC patients were diagnosed with limited disease. The median overall survival was 21 months and multivariate analysis indicated that PS and time until diagnosis were independent prognostic factors. Conclusions: Although more than half of young patients are at stage IV when diagnosed, prognosis does not seem as dismal as previously considered. Larger studies need to be conducted in order to elucidate the possible role of chronic hepatitis in the pathogenesis of SCLC in young patients.
P35.29 The Genomic Landscape of Lung Cancer Patients Highlights Age-Dependent Mutation Frequencies and Clinical Actionability in Young Patients
