"You're really walking along the razor's edge": A meta-synthesis on the existential cost of breast cancer related to financial toxicity.

Cancer-related financial toxicity (FT) is a challenge of living with and beyond breast cancer (BC). A systematic review and meta-synthesis was conducted to report the experience of individuals with BC regarding cancer-related FT. Data were searched in MEDLINE, Embase, Cinahl, Scopus, PsycINFO, and Web of Science from inception. Eligibility was restricted to original qualitative studies. We performed a meta-synthesis by generating interpretative themes and a model of cancer-related FT. Thirty-two studies were included, encompassing 1080 individuals with BC. Of these studies, 17 were conducted in North America (719 individuals), nine in South, East, and West Asia (238 individuals), two in Oceania (53 individuals), and four in Northwest Africa (70 individuals). Five themes were identified: (i) the existential cost of cancer, (ii) the impact of insurance complexity, (iii) the need for timely and accessible information, (iv) seeking possible help, (v) negotiating daily life. The review highlights the lack of original qualitative studies conducted in Europe. Socioeconomic status, insurance, and employment amplify inequalities and shape the experience of FT. The interpretative model could support individuals with BC and providers' communication.