Introduction: following the 2009-2013 cancer plan, trials with nurse coordinators (IDEC) in oncology showed a positive impact on the fluidity of care pathways. The 2014-2019 cancer plan guides their focus toward complex cases. The objective of this study is to build a tool to facilitate the recruitment of patients likely to experience a complex path. Method: this research was formed of two phases. The first one collected the elements of the dimensions that can predict the complexity of the care path, using a focus group. The second consisted of the reduction and selection of priority items and of estimating their importance using the Delphi method. Results: from the twelve selected items, two were recognized as having a significant risk scoring, seven probably correlated with a complex pathway, and three were unrelated to the complexity of the pathways. Discussion: this instrument should be validated by a test sample to evaluate its psychometric and metrological properties and its feasibility.