154 Background: By allowing patients (pts) to self-report key issues related to their quality of life and symptoms, PROs have important clinical and research implications. The PanCAN Registry, which began collecting data in July 2015, is a pancreatic cancer-specific global online registry enabling pts to report sociodemographics, disease/management characteristics, and PROs via online surveys. We sought to describe pt experiences with the PanCAN Registry. Methods: We assessed individual characteristics and interactions with the registry (visits, survey completions, and longitudinal use) from 7/2015-10/2019 for pts who provided permission to use their data. The registry allows pts to complete surveys about their experience (e.g. basics of pancreatic cancer, general information), symptoms (e.g. fatigue, pain), diagnostics (e.g. labs, scans), and drug therapy (e.g. type, frequency). We validated PROs using the PanCAN Know Your Tumor database. For a subset of pts (those with de novo metastatic disease), we compared PROs, treatment patterns, and side effects by age (+/- 65 years) and treatment site (community or academic). Results: Of 2,836 pts who visited the registry, 2,076 (73%) completed at least one survey (median age = 64 [range: 18-97], 48% women, 92% white, 32% metastatic disease). Pts most commonly completed the basics (73%), general information (39%), and drug therapy (37%) surveys. Overall, 10% answered surveys longitudinally. We observed 95% concordance between PROs and the PanCAN Know Your Tumor database. Among the 667 pts with de novo metastatic disease, 34% were older (age 65+) and 50% were treated at academic sites. Younger pts were more hopeful about the treatment plan (strongly agree: 24% v 12%, p < .01) and reported less constipation (moderate/severe: 33% v 48%, p < .01) compared with older pts. Pts treated at academic sites reported less frequent treatment breaks of > 2 weeks (28% v 58%, p = 0.01) and more frequent severe cytopenias (27% v 12%, p = 0.01) compared with those treated at community sites. Conclusions: With > 2,800 pts visiting the PanCAN registry and > 70% completing a survey, these findings demonstrate the feasibility, robustness, and research potential of an online PRO registry. We observed important differences by age and treatment site regarding pts’ outlook, symptoms, treatment patterns, and side effects. With increasing focus on PROs, registries like this can facilitate standardized PRO reporting and monitoring, while also providing a valuable research database.