RESEARCH ARTICLE Open Access

How do we estimate survival? External validation of a tool for survival estimation in patients with Decision Curve Analysis (DCA), and compared the Italian patient data to the training set (United States) and first Piccioli et al. BMC Cancer (2015) 15:424 DOI 10.1186/s12885-015-1396-5Stockholm, Sweden Full list of author information is available at the end of the articleexternal validation set (Scandinavia). Results: The Italian dataset contained 287 records with at least 12 months follow-up information. The AUCs for the three-month and 12-month estimates was 0.80 and 0.77, respectively. There were missing data, including the surgeon’s estimate of survival that was missing in the majority of records. Physiologically, Italian patients were similar to patients in the training and first validation sets. However notable differences were observed in the proportion of those surviving three and 12-months, suggesting differences in referral patterns and perhaps indications for surgery. Conclusions: PATHFx was successfully validated in an Italian dataset containing missing data. This study demonstrates its broad applicability to European patients, even in centers with differing treatment philosophies from those previously studied