Drawing on interviews with staff and patients, we ask how breast cancer care in 2020 has affected views of a previous targeted, tailored or personalised medicine. How is this form of experimental care – simultaneously research and treatment – reconfigured in retrospect?

In 2018 we returned to a research-intensive breast cancer service we had studied five years previously (Day et al. 2017). We found a more hopeful atmosphere with increased options for treatment, close monitoring and intricate adjustments to therapy which led participants to approach advanced cancers as chronic conditions (Day et al. 2021).

More recently, Covid-19 has had a pronounced impact. It has promoted an increasingly digital practice with simplified treatments and extended data linkage. Clinical trials and tissue banking have been restricted while health care records are linked into a greater variety of data sets in near ‘real time’ analysis. Our own research belongs with these developments as it too has become digitised. A single ‘case’, a collaboration between three of us –  researchers and a recipient of experimental care for advanced breast cancer – illustrates developments before and during Covid-19. We ask how observational, in silico research is reconfiguring experimental care and consider a variety of implications for ‘chronic living’.