Characterizing Terminality in Cancer: Conceptual Analysis and Proposal for a Unified Definition for Clinical Contexts.

Objective: Systematically map and synthesize the range of definitions, diagnostic criteria, and operational characteristics associated with these key concepts in the oncology literature. The ultimate aim is to generate a comprehensive evidence base to inform the development of a unified, pragmatic definition for implementation within institutional context. Introduction: The concepts of "terminal disease/terminal illness," "advanced/irreversible disease/advanced cancer," and related terms are foundational to oncology and palliative care, guiding critical decisions in treatment goals, care transitions and resource allocation. However, a pervasive lack of conceptual clarity and operational consensus creates variability in clinical practice, research inclusion criteria, and healthcare policy. This heterogeneity can lead to miscommunication, delayed palliative care integration, and inequitable service access. Inclusion criteria: Original research articles (qualitative or quantitative), conceptual or theoretical review articles, national or international clinical guidelines, formal consensus statements from specialized societies and position papers that focus primarily on defining or characterizing concepts for the target terms ("terminal disease/terminal illness", "advanced/irreversible disease/advanced cancer" in oncology) in the adult population. Methods: This review will adhere to the PRISMA methodology and will be reported following the PRISMA extension for Scoping Reviews (PRISMA-ScR). A comprehensive search strategy will be executed across multiple databases (MEDLINE/PubMed, Embase, Scopus, Web of Science, LILACS) and sources of gray literature. We will include scholarly articles, clinical guidelines, and consensus statements that address definitions or operationalization of terminal/advanced cancer in adult populations. Two independent reviewers will screen titles, abstracts, and full texts, extracting data into a standardized form. Data extraction will focus on the specific terminology used, textual definitions, proposed operational criteria (prognostic timelines, performance status, treatment refractoriness), and the context in which definitions are applied.