A Directory of Poor Prognostic Markers of Breast Cancer for the Oncology Practice
Fawwaz S. Al Joudi *
Department of Biotechnology, Faculty of Engineering, McMaster University, 1280 Main Street, Hamilton, Ontario, Canada.
Raad S. Yusufani
Department of Surgery, Sharjah University Medical School, Sharjah, U.A.E.
Suhair A. Ahmed
Nutrition Clinic, Red Crescent Hospital, Mansour Street, Al-Mansour, Baghdad, Iraq.
*Author to whom correspondence should be addressed.
Abstract
Breast cancer is biologically heterogeneous, and the prognostic significance of a biomarker depends on molecular subtype, disease stage, treatment exposure, assay method and the clinical outcome under evaluation. This narrative evidence directory organises reported biomarkers associated with unfavourable outcomes in breast cancer and distinguishes their potential roles in prognosis, treatment response and disease monitoring. The literature was identified through an iterative manual search of peer-reviewed publications and relevant review articles. Eligible material included clinical studies and evidence syntheses that reported an association between a tissue, cellular, molecular, immune, circulating or clinicopathological marker and recurrence, metastasis, treatment resistance, progression-free survival, disease-free survival or overall survival. The extracted markers were grouped by general or unspecified breast cancer, triple-negative breast cancer, invasive disease, metastatic disease, luminal subtypes, HER2-positive disease, basal-like disease, male breast cancer, uncommon presentations, immunotherapy-related settings and treatment-associated contexts. The resulting tables contain more than 200 reported markers. This breadth illustrates the intensity of biomarker discovery but does not imply equivalent evidentiary strength or clinical readiness. Established markers such as oestrogen receptor, progesterone receptor, HER2, tumour stage, histological grade and selected validated multigene assays have substantially greater clinical support than most exploratory single-gene or bioinformatic candidates. The directory is therefore intended as a structured map of published associations rather than a clinical testing guideline. Translation into routine oncology practice requires analytical validation, independent clinical validation, clearly defined cut-offs, demonstration of incremental prognostic value and evidence that testing improves clinical decision-making.
Keywords: Prognostic markers, breast cancer, oncology practice, metastatic disease, hormone receptors