OBJECTIVES: Breast Cancer (BC) is the most prevalent cancer among Portuguese women, being responsible for significant socio-economic burden. Every year there are 7.500 new cases and over 1.700 women die from this disease. To estimate the direct costs for the NHS of a BC patient, a model was built based on the patient pathway. METHODS: The patient pathway was designed considering published guidelines, desk research and input from oncology experts. It was developed for the most common BC subtype (Luminal B) and for HER2-positive, covering the full patients’ journey (from diagnosis to follow-up). BC staging was coded into four categories: very early, early, locally advanced, and metastatic. Direct costs included costs of appointments, exams, treatments, and other relevant interventions. Patient shares for BC subtypes, categories and treatment options were included in the model to estimate the total direct cost of the BC patient journey. RESULTS: Overall, BC incidence accounts for up to 285 million euros of total direct cost for the NHS. The estimated average direct cost for the NHS per BC patient is 37.968€, with 24.126€ (63.5%) accounting for therapies cost and 13.842€ (36.5%) corresponding to care activities. For Luminal B BC, treatment cost in very early and early stages are -40% and -21%, respectively, compared to treatment in the metastatic stage (12.045€ and 15.851€ vs 19.972€). For HER2+ BC patients, very early and early stages represent -89% and -74%, respectively, compared to the metastatic stage (12.883€ and 28.763€ vs 112.280€). CONCLUSIONS: Besides considerable health and social burden for patients, BC is associated with a very high economic impact. The patient pathway model is an important tool to assess BC impact to NHS budget and resource allocation. It reflects the importance of prevention and early detection of BC to maximize health gains and mitigate economic impact in BC patients.