e13071 Background: Body mass index (BMI) is inversely associated with lung cancer risk, particularly in former or current smokers. KRAS mutant non-small cell lung cancer (NSCLC) has been shown to be highly associated with smoking status. Therefore, we sought to investigate the association of BMI and stage in a cohort of patients with KRAS mutant NSCLC. Methods: Patients with KRAS mutant lung cancer who underwent tumor genotyping using next generation sequencing testing were identified. BMI( kg/m2 ) was categorized as: Underweight ( < 18.5), normal weight (18.5 – 24.9), overweight (25-29.9) and obese (≥30). Chi-square and t-tests were performed to test association between stage (I vs. II+) and BMI (4 categories), and stage and BMI as a continuous variable, respectively. Results: From 5/2013 to 9/2016, 201 patients with KRAS mutant NSLC were identified. Of these, 178 (88.6%) were current or former/ever smokers (SM) and 23 (11.4%) were never smokers (NS). In the SM group, 114 were female and 64 male with a median age at diagnosis of 66.5 years (range 45-93). In the NS group, 15 were female and 8 male with a median age at diagnosis of 71.5 years (range 51-92) (age for NS vs. SM p = 0.0439). Fifty-two (25.9%) patients presented with stage I disease, 149 (74.1%) presented with advanced (stage II-IV) disease. There was no significance in the BMI at diagnosis of SM vs. NS or by sex. There was a difference (p = 0.0430) in the BMI between patients with stage I disease (mean 28.6) and patients with stage II or greater disease (mean 26.6). This was also seen in SM with stage I vs. II+ disease (p = 0.0417); however, this was no longer significant in SM when broken out by sex or in NS alone. Conclusions: We identified a significant difference in BMI in patients with KRAS mutant NSCLC with stage I vs. advance stage disease, with a higher BMI associated with early stage disease at diagnosis. The lower BMI in patients with more advanced stage may be a confounding variable explained by comorbidities, and the lung cancer itself. It is unlikely that treatment effects were a factor as the KRAS testing was done prior to initiating therapy. Further studies looking at BMI and survival analysis in patients with mutant KRAS NSCLC are warranted.
Role of combining neutrophil‑to‑lymphocyte ratio and pretreatment body mass index in predicting progression‑free survival in patients with non‑small cell lung cancer treated with nivolumab