The accurate and transparent reporting of clinical trial results is of the utmost importance to all stakeholders (clinicians, patients, regulatory agencies, the global scientific public) for several reasons. It enables precise interpretation of trial results, facilitates cross-trial comparisons and meta-analyses, and, most importantly, allows informed clinical decision-making, ultimately benefiting patients and saving lives. The standardization of clinical trial end points is 1 crucial step toward this. With respect to clinical trials of adjuvant breast cancer therapy, the definition of the Standardized Definitions for Efficacy End Points (STEEP) criteria by a working group convened by Hudis et al¹ in 2007 was a big achievement in terms of harmonization of trial end points, eventually resulting in invasive disease-free survival (IDFS) being used as a primary end point in most contemporary clinical trials. IDFS includes locoregional and distant recurrences as well as second primary cancers (breast and nonbreast origin) and all causes of death. IDFS is also seen as an early surrogate marker for overall survival. Since 2007, international experts have reassessed the STEEP criteria and evaluated IDFS and potentially even better and more focused end points.² More specifically, Tolaney et al² used simulations to investigate the impact of second primary nonbreast cancers (SPNBCs) on a primary trial end point and eventually proposed a new standardized end point: invasive breast cancer–free survival (IBCFS). IBCFS includes all event types included in IDFS, except for SPNBCs. Unfortunately, they did not provide enough details to enable an exhaustive interpretation of the results and conclusions. At first glance, it appears logical to exclude events that are not (except rarely, it is hoped, as treatment adverse effects) related to the disease itself. However, the exclusion of SPNBCs from the proposed composite end point of IBCFS raises an important question: How should SPNBCs be handled during the statistical analysis? As an SPNBC is an intercurrent event,³ it undoubtedly, and essentially, is a postrandomization event that can in principle affect the interpretation of the results. In investigating ways to correctly deal with the issue, we ask another consequential question: What is the (strategic) objective of IBCFS (as compared with IDFS)?