The prognostic performance of Adjuvant! Online and Nottingham Prognostic Index in young breast cancer patients

Background: Limited data are available on the prognostic performance of Adjuvant! Online (AOL) and Nottingham Prognostic Index (NPI) in young breast cancer patients. Methods: This multicentre hospital-based retrospective cohort study included young (p40 years) and older (55- 60 years) breast cancer patients treated from January 2000 to December 2004 at four large Belgian and Italian institutions. Predicted 10-year overall survival (OS) and disease-free survival (DFS) using AOL and 10-year OS using NPI were calculated for every patient. Tools ability to predict outcomes (i.e., calibration) and their discriminatory accuracy was assessed. Results: The study included 1283 patients, 376 young and 907 older women. Adjuvant! Online accurately predicted 10-year OS (absolute difference: 0.7%; P = 0.37) in young cohort, but overestimated 10-year DFS by 7.7% (P = 0.003). In older cohort, AOL significantly underestimated both 10-year OS and DFS by 7.2% (P<0.001) and 3.2% (P = 0.04), respectively. Nottingham Prognostic Index significantly underestimated 10-year OS in both young (8.5%; P<0.001) and older (4.0%; P<0.001) cohorts. Adjuvant! Online and NPI had comparable discriminatory accuracy. Conclusions: In young breast cancer patients, AOL is a reliable tool in predicting OS at 10 years but not DFS, whereas the performance of NPI is sub-optimal.