Chemotherapeutics are the mainstay treatment for metastatic breast cancers. However, the chemotherapeutic failure caused by multidrug resistance (MDR) remains a pivotal obstacle to effective chemotherapies of breast cancer. Although in vitro evidence suggests that the overexpression of ATP-Binding Cassette (ABC) transporters confers resistance to cytotoxic and molecularly targeted chemotherapies by reducing the intracellular accumulation of active moieties, the clinical trials that target ABCB1 to reverse drug resistance have been disappointing. Nevertheless, studies indicate that ABC transporters may contribute to breast cancer development and metastasis independent of their efflux function. A broader and more clarified understanding of the functions and roles of ABC transporters in breast cancer biology will potentially contribute to stratifying patients for precision regimens and promote the development of novel therapies. Herein, we summarise the current knowledge relating to the mechanisms, functions and regulations of ABC transporters, with a focus on the roles of ABC transporters in breast cancer chemoresistance, progression and metastasis.

Oral mucositis (OM) is a painful condition caused by chemotherapeutic or radiotherapeutic cancer treatments, occurring in patients with different tumour characteristics and locations. OM greatly impacts a patient’s quality of life and cancer recovery. Current OM management strategies are not providing sufficient prevention and treatment; new approaches to injury management are needed. Studies on the benefit of omega-3 free fatty acids (FFA) in human health have increased significantly in recent years. FFA properties have been studied extensively, including their potential therapeutic use in inflammatory conditions. However, omega-3 FFA’s use as a supplementary treatment for OM has not been clinically tested. Preliminary evidence suggests that utilising FFA to manage OM could be a useful strategy for lesion management, assisting with healthy oral mucosa recovery. This review will describe the incidence, risk factors, biology of OM and the current treatment strategies, leading to a discussion of the utility of omega-3 FFA as a novel therapeutic agent for OM.