Jonathan Montomoli1, Rune Erichsen1, Mette Nørgaard1, Morten Høyer2, Jesper Bach Hansen3, Jacob Bonde Jacobsen11Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark; 2Department of Oncology, Aarhus University Hospital, Aarhus, Denmark; 3Medical Department of Gastroenterology, Aalborg Hospital, Aalborg, DenmarkObjective: Primary liver cancer (PLC) is a serious disease with high mortality. During the last decade, improvements in the diagnostic procedures and treatment of PLC may have improved survival. However, few updated longitudinal studies examined this issue. In a population-based setting, we studied changes in the prognoses over time.Methods: Between 1998 and 2009, we identified all patients with PLC in the central and northern Denmark regions, with a combined population of 1.8 million. We determined age- and period-stratified survival, and computed mortality rate ratios (MRRs) with 95% confidence intervals (CIs), using Cox proportional hazard regression to assess changes over time, while controlling for age and gender. We conducted the analyses for PLC overall and separately for hepatocellular carcinoma (HCC) and cholangiocarcinoma, respectively.Results: We included 1064 patients with PLC. Their median age was 69 years (range 17–94 years). The number of patients diagnosed with PLC in the period 2007–2009 was approximately 40% higher than the number in 1998–2000. One-year survival increased from 16% in 1998–2000 to 28% in 2007–2009, corresponding to an adjusted 1-year MRR of 0.65 (95% CI: 0.54–0.79). In patients aged ,60 years, we found the most pronounced increase in 1-year survival, from 14% to 49% in women and from 19% to 41% in men. The 3- and 5-year survival in the entire cohort increased from 5% to a predicted 11% and from 2% to a predicted 7% during our study period, respectively. Accordingly, the expected 3- and 5-year adjusted MRRs were 0.68 (95% CI: 0.57–0.82) and 0.68 (95% CI: 0.57–0.81), respectively. One-, 3-, and 5-year survival improved during the study period for both HCC and cholangiocarcinoma.Conclusion: PLC survival remains poor in the Danish population, although we observed an increase over the period 1998–2009, particularly in young people.Keywords: liver neoplasm, prognosis, mortality, epidemiology