Background: A Memorial Sloan Kettering (MSKCC) nomogram predicts disease specific survival (DSS) for gastric adenocarcinoma. The goal of this study is to use a cancer registry to compare nomogram predicted survival with actual survival in the general population.
Methods: All patients undergoing surgery for gastric adenocarcinoma from the Surveillance, Epidemiology, and End Results (SEER) database (1988-2012) were studied.
Results: 6954 patients were identified. Majority of cancers were in the antrum (30.2%), and had intestinal histology (73.7%). Median follow-up was 8.2 years. Five year DSS for nomogram risk groups (0-25%, 26-50%, 51-75%, and 76-100%) was 23%, 48%, 57%, and 81% respectively. Actual DSS was 7-15% lower than nomogram predicted DSS. Relative to patients in the 76-100% 5-year DSS risk group, patients in the 0-25%, 26-50%, and 51-75% groups had significantly higher risks of death with hazard ratios of 6.84 (95%CI 6.12-7.65), 3.30 (95%CI 2.83-3.86), and 2.64 (95%CI 2.30-3.03), respectively (all P < 0.001). The concordance index for 5-year nomogram predicted DSS was 0.68 (95%CI 0.67-0.69).
Conclusions: The MSKCC gastric cancer nomogram over-estimates DSS from gastric cancer in the general population and has a moderate concordance index. Predictive tools generated at specialized institutions may not perform as well in the general population.
Keywords: SEER program; gastric cancer; nomograms; prognosis; registries; validation studies.
© 2015 Wiley Periodicals, Inc.