Our findings suggest that the frequency of EGFR mutations in Latin America lies between that of Asian and Caucasian populations and therefore support the genetic heterogeneity of NSCLC around the world.

Since the International Association for the Study of Lung Cancer (IASLC), American Thoracic Society (ATS) and European Respiratory Society (ERS) reported a new lung adenocarcinoma (ADC) classification, several groups have validated its association with prognosis in early stage disease. To our knowledge, there are no studies in advanced disease.We reviewed 313 patients with invasive lung ADC who were re-classified using the new IASLC/ATS/ERS criteria. Patients received platinum-based chemotherapy. Clinical characteristics, EGFR mutations, response and progression-free survival (PFS) after chemotherapy and overall survival were analysed.ADCs were classified as lepidic 7.4%, acinar 44.7%, papillary 10.1%, micropapillary 3.5% and solid 34.2%. When patterns were lumped into groups, response rates and PFS to platinum-based chemotherapy were better in high-grade ADC (micropapillary, papillary and solid-predominant) versus intermediate-grade ADC (lepidic and acinar-predominant) (36.9% versus 25.4% p50.034 and 6.4 versus 5.5 months p50.009, respectively). Overall survival was better in high-grade ADC (25 versus 16.8; p50.023). Factors associated with better overall survival were Eastern Cooperative Oncology Group (0-1), EGFR mutations and highgrade ADC.Prognostic differences found with the new classification in early disease may not apply to patients with advanced disease. Unlike in early stages, patients with high-grade ADC have longer overall survival compared with intermediate-grade ADC, probably due to a better response to chemotherapy. @ERSpublications Impact of the novel classification of lung adenocarcinoma in advanced disease

NSCLC patients who smoked tobacco/cigarettes differed from those having a background of WSE regarding tumor histology, mutation profile, response rate, and OS, indicating that different carcinogenic mechanisms were induced by these two types of smoke exposure.

KRAS mutation status is a good biomarker for response to EGFR-TKIs in patients with NSCLC. KRAS mutational status could impact the decision to give CT or EGFR-TKIs as a second line of treatment to patients with NSCLC, particularly in patients with WT-EGFR.

Tumor cells cultured in three-dimensional models provide a more realistic and biologically meaningful analysis of the initial phases of cancer development and drug resistance. Several studies have demonstrated that culture of cancer cells in three dimensions induces cellular resistance to a variety of anti-neoplastic drugs by poorly understood mechanisms. The role of the transcription factor NF-kappaB and inhibitors of apoptosis proteins (IAPs) in the onset and development of drug resistance during tumor spheroid growth has not been established. In this work, we found a significant increase in the activity and expression of NF-kappaB and its downstream target XIAP (X-linked IAP) in cancer cells grown as multi-cellular tumor spheroids. Blocking XIAP expression with RNA interference markedly increased the sensitivity of cancer tumor spheroid cells toward anti-neoplastic drugs, indicating a role for IAPs in establishing drug resistance. In turn, inhibition of NF-kappaB by negative dominants suppressed spheroid formation, whereas overexpression of the upstream kinase IkappaBKbeta increased their growth and resistance. The present data suggested that NF-kappaB and its downstream target XIAP were essential for the growth and drug resistance of small avascular tumor.