Cross-cultural adaptation of the PROFFIT Instrument to measure financial toxicity in people living with cancer within a UK population

•Financial toxicity due to out-of-pocket expenses poses a problem even in universal healthcare systems.•FT's impact on well-being, quality of life, treatment adherence needs attention in UK and Europe.•Financial Toxicity tool PROFFIT can tailor interventions for cancer patients to address and measure financial hardships.•Using the UK version of the PROFFIT, researchers can measure and compare FT in English-speaking countries.