Eligibility criteria

Task: Specify inclusion and exclusion criteria including those relating to participants, interventions, comparisons, outcomes, study design and characteristics (e.g. years when conducted, required minimum follow-up). Note whether these were applied at the study or individual level i.e. whether eligible participants were included (and ineligible participants excluded) from a study that included a wider population than specified by the review inclusion criteria. The rationale for criteria should be stated.

Text: In describing the general eligibility criteria used across the EBCTCG systematic reviews, it is worth noting the omnibus nature and history of this project,* which involves the collaboration of hundreds of research groups from around the world. Over the last 30 and more years, we have identified more than 600 randomised trials of treatments for women with operable breast cancer, and collected IPD from ~500 of these, on more than 600,000 women. In the early 1990s, we routinely sought IPD from every randomized trial that had compared treatments for women who had been diagnosed with operable breast cancer (or breast cancer which might become operable through the use of neo-adjuvant therapy), in which recurrence or death was a principal outcome; regardless of other factors such as age, tumour characteristics, other interventions or place of treatment. As the scale of the task of collecting, processing and analyzing IPD for every trial grew, our efforts became more focused. This includes engagement with members of the EBCTCG, principally through its Steering Committee to prioritise work on comparisons of specific treatments, followed by concerted efforts to gather the IPD for these comparisons, and to prepare, discuss and publish the associated meta-analyses. The comparisons being tackled in the last decade, and continuing, relate to hormonal therapy (principally, ovarian ablation and suppression, tamoxifen and aromatase inhibitors), chemotherapy (including taxanes, anthracyclines and dose dense therapy), other systematic therapies (including bisphosphonates and biological therapies such as trastuzumab and bevacizumab) and local therapy (including radiotherapy and surgery and more general question such as the management of the axilla). Alongside the research into the main effects of treatments on recurrence, mortality and breast cancer mortality; we also study the effects on second cancers, non-breast-cancer mortality and cardiovascular disease.

* Darby S, Davies C, McGale P. The Early Breast Cancer Trialists’ Collaborative Group: a brief history of results to date. In Davison AC, Dodge Y, Wermuth N (editors). Celebrating statistics. Oxford University Press, Oxford, 2005 pp.185-198.