Long non-coding RNAs and drug resistance in breast cancer patients: a scoping review

Breast cancer (BC) is the most prevalent cancer among women. Despite improvements in the detection and treatment of BC, drug resistance is widespread, making it the leading cause of cancer mortality in women. Long non-coding RNAs (lncRNAs) have been shown to play essential roles in regulating drug resistance in pre-clinical models. However, their clinical relevance remains largely unexplored. This review addresses this gap by identifying and examining lncRNAs with potential predictive value as biomarkers for drug resistance in BC cancer patients. A systematic search (last updated February 7, 2024) was conducted across five databases (Cochrane Library, Embase, PubMed, Scopus, and Web of Science) for research articles in English, published after 2010, involving BC patients who underwent treatment. Following the selection and review process, 66 studies were short-listed, and 185 unique lncRNAs linked to drug resistance in BC patients were identified. Notably, only five lncRNAs (BCAR4, CCAT2, DSCAM-AS1, GAS5, and H19) were reported in at least two independent studies, indicating the scarcity of replicated evidence in clinical cohorts. Receiver operating characteristic curve analysis for these five lncRNAs confirmed that BCAR4, GAS5, and H19 expression levels have prognostic potential for predicting chemotherapy response. However, further validation is required before lncRNAs can be effectively utilized as prognostic markers in a clinical setting.