 Caldas led the METABRIC (Molecular Taxonomy of Breast Cancer International Consortium) study, analysing the genome and transcriptome of tumours from nearly 2,000 women and comparing this with long-term clinical information including survival, age and diagnosis.The METABRIC study concluded that breast cancer was at least ten different subtypes, characterised by distinct genomic drivers.In 2019, the team published research showing the subtype a women's breast cancer is initially placed in could predict the likelihood of the tumour returning or metastasising over the next 20 years.