Background: Conditional survival is the survival probability after already surviving a predefined time period. This may be informative during follow-up, especially when adjusted for tumor characteristics. Such prediction models for patients with resected pancreatic cancer are lacking and therefore conditional survival was assessed and a nomogram predicting 5-year survival at a predefined period after resection of pancreatic cancer was developed. Methods: This population-based study included patients with resected pancreatic ductal adenocarcinoma from the Netherlands Cancer Registry (2005–2016). Conditional survival was calculated as the median, and the probability of surviving up to 8 years in patients who already survived 0–5 years after resection was calculated using the Kaplan–Meier method. A prediction model was constructed. Results: Overall, 3082 patients were included, with a median age of 67 years. Median overall survival was 18 months (95% confidence interval 17–18 months), with a 5-year survival of 15%. The 1-year conditional survival (i.e. probability of surviving the next year) increased from 55 to 74 to 86% at 1, 3, and 5 years after surgery, respectively, while the median overall survival increased from 15 to 40 to 64 months at 1, 3, and 5 years after surgery, respectively. The prediction model demonstrated that the probability of achieving 5-year survival at 1 year after surgery varied from 1 to 58% depending on patient and tumor characteristics. Conclusions: This population-based study showed that 1-year conditional survival was 55% 1 year after resection and 74% 3 years after resection in patients with pancreatic cancer. The prediction model is available via www.pancreascalculator.com to inform patients and caregivers.

Additional Metadata
Keywords Conditional survival, Pancreatic cancer, Prediction model, Survival
Persistent URL dx.doi.org/10.1245/s10434-020-08235-w, hdl.handle.net/1765/124903
Journal Annals of Surgical Oncology
Citation
Latenstein, A.E.J. (Anouk E. J.), van Roessel, S. (Stijn), van der Geest, L.G.M, Bonsing, B.A, Dejong, C.H.C. (Cornelis H. C.), Groot Koerkamp, B, … Besselink, M.G. (2020). Conditional Survival After Resection for Pancreatic Cancer: A Population-Based Study and Prediction Model. Annals of Surgical Oncology. doi:10.1245/s10434-020-08235-w