Cause of death for patients with breast cancer: discordance between death certificates and medical files, and impact on survival estimates oleh Hava Izci, Tim Tambuyzer, Jessica Vandeven, Jérôme Xicluna, Hans Wildiers, Kevin Punie, Nynke Willers, Eva Oldenburger, Els Van Nieuwenhuysen, Patrick Berteloot, Ann Smeets, Ines Nevelsteen, Anne Deblander, Harlinde De Schutter, Patrick Neven, Geert Silversmit, Freija Verdoodt