Abstract P4-18-03: IBCSG BIG 1-98 study: The long-term follow-up experience
Authors: Giobbie-Hurder Anita , Thürlimann Beat , Ejlertsen Bent , Neven Patrick , Coleman Robert E , Smith Ian , Wardley Andrew M , Láng István , Colleoni Marco , Debled Marc , Forbes John F , Price Karen N , Regan Meredith M , Rabaglio Manuela , Goldhirsch Aron , Coates Alan S , Gelber Richard D 
Published: May 2015

Abstract
Background
Industry-sponsored clinical trials often have duration of patient follow-up that is defined according to regulatory requirements. However, in diseases such as endocrine-responsive, early breast cancer, recurrences occur after protocol follow-up, and monitoring of long-term toxicity is important. It is challenging to continue patient follow-up after industry sponsorship ends. Transferring responsibility for additional follow-up to the participating academic centers is required. One such example is the long-term follow-up (LTFU) of patients in the Breast International Group (BIG) 1-98 Trial. We present the procedures and current status of the BIG 1-98 LTFU protocol.
Methods
In 2010, the BIG 1-98 trial embarked on a new LTFU protocol to gather data on patient outcomes for an additional five years after study completion (2011-2015). Industry sponsorship ceased at the end of 2010. The LTFU study is designed as an observational, non-interventional study to continue the collection of simplified and updated data on survival, disease status, and long-term adverse events from centers participating in the 4-arm option. The International Breast Cancer Study Group (IBCSG) is sponsoring BIG 1-98 LTFU, and per case reimbursement is available.
Results
The potential BIG 1-98 LTFU cohort consists of the 148 academic medical centers that participated in the 4-arm option with a maximum of 6843 patients enrolled to the parent study. In May 2014, approximately 3 years after initiation of the LTFU protocol, 96 centers had agreed to participate, of which 67 sites had activated the protocol and submitted LTFU data; 31 additional centers were not participating, and the status of 21 centers was unknown.
Participation StatusNumber of CentersPatients Enrolled in BIG 1-98Closed317Not Participating28643No response/Unknown21850Yes, participating965333 Activated674215Not Activated291118Totals1486843
Because the original BIG 1-98 informed consent indicated life-long follow-up, only three countries required patient re-consent in order to participate. At least one LTFU data submission has occurred for 73% of patients participating in the LTFU (May 2014).
Conclusion
Long-term follow-up for a large-scale clinical trial is feasible, but challenging. The methods used for BIG 1-98 LTFU will be described and the status will be updated at the meeting.
Citation Format: Anita Giobbie-Hurder, Beat Thürlimann, Bent Ejlertsen, Patrick Neven, Robert E Coleman, Ian Smith, Andrew M Wardley, István Láng, Marco Colleoni, Marc Debled, John F Forbes, Karen N Price, Meredith M Regan, Manuela Rabaglio, Aron Goldhirsch, Alan S Coates, Richard D Gelber. IBCSG BIG 1-98 study: The long-term follow-up experience [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P4-18-03.