Background Advance care planning (ACP) is the process of discussing and recording personal values, beliefs and preferences, to guide clinical decision-making in the event that person lose capacity to make or communicate their treatment decisions. Despite recommendations from guidelines, rates of documentation for people with cancer are considerably low.

Aim To systematically clarify and consolidate the evidence base of ACP in cancer care by exploring how it is defined; identifying benefits, and known barriers and enablers across patient, clinical and healthcare services levels; as well as interventions that improve advance care planning and are their effectiveness.

Methods A systematic overview of reviews was conducted and was prospectively registered on PROSPERO. PubMed, Medline, PsycInfo, CINAHL, and EMBASE were searched for review related to ACP in cancer. Content analysis and narrative synthesis were used for data analysis. The Theoretical Domains Framework (TDF) was used to code barriers and enablers of ACP as well as the implied barriers targeted by each of the interventions.

Results Twenty-nine reviews met the inclusion criteria. There was a lack of consistency in relation to definitions. Many proposed benefits did not actualize into empirically identified benefits. Interventions tended to target a different population and barriers, than the ones where the majority of evidence identified as a problem.

Conclusion To improve ACP uptake in oncology settings; the definition should include key categories that clarify the utility and benefits. Interventions need to target healthcare providers and empirically identified barriers to be most effective in improving uptake.