Evaluation of disease-free survival (DFS) as a surrogate for overall survival (OS) in the adjuvant therapy of HER2-positive early breast cancer (EBC) calls for individual-patient data (IPD). (March 2017) - Saad, E.; Delaloge, S.; Mavroudis, D.; Perez, E.; Piccart-Gebhart, M.; Schneider, B.; Wolmark, N.; Buyse, M.; Burzykowski, T.