e17521 Background: The cancer anorexia-cachexia syndrome (CACS) is a debilitating syndrome of involuntary weight loss, anorexia, declining function, muscle catabolism, and inflammation. It affects many patients with cancer, especially those with advanced disease. We aimed to describe the experience of a group of patients with advanced lung cancer who meet published weight-based criteria for CACS. Methods: Tablet computers were used to collect patient-reported outcomes data from 97 patients with advanced non-small cell lung cancer, using the Patient Care Monitor v2.0 and the FACIT family of questionnaires. 25 patients met published weight criteria for CACS (>=5% weight loss in the past 6 months). 51 patients with stable weights were used as a comparison group; those lacking weight data were excluded. Statistical comparisons were made between these groups to explore differences in symptoms, quality of life, and survival. Results: Patients meeting weight criteria for CACS had lower serum albumins (median 3.7 vs. 3.9, p=0.006) and worse performance status by Karnofsky and ECOG (70 vs. 80, p=0.004, and 2 vs. 1, p=0.027). CACS patients had worse FAACT anorexia-cachexia subscale scores (34.5 vs. 38.5, p=0.018) but were not statistically more likely to be prescribed CACS therapies; only 17% of patients in the CACS group were on medication for this (N=4). FACIT fatigue subscale scores were not statistically different between groups, nor was quality of life by FACT-G. Grip strength and 6-minute walk distance were also not statistically different. Patients in the CACS group had a significantly shorter survival (HR 2.066 [95% CI=1.229,3.474], p=0.005). Conclusions: Patients with advanced non-small cell lung cancer who meet standard weight-based criteria for CACS have inferior survival compared to a similar population without weight loss. Though traditional descriptions of CACS presume a general impairment in quality of life, we did not find statistical differences here aside from the anorexia-cachexia subscale score of FAACT. Few patients were prescribed medication to address symptomatic anorexia/cachexia, suggesting it may be an unmet need in patients with advanced lung cancer.