Biotherapies in Solid Tumors: Are Negative Results Still of Low Priority for Publication?

In 2005, we performed the largest survey on clinical trials of biotherapies for all solid tumors and found indirect evidence of a publication bias: editors of medical journals were more prone to publish positive results independently from the quality of the studies. We collected data from 2003 to 2015 in 487 studies, and the publication bias previously described was not found in the years between 2010 and 2015: this could be related to changes and/or innovations in the guidelines and editorial policies of oncology journals occurred over the last years.