OBJECTIVES: A drug protocol that incorporated docetaxel with the conventional anticancer agents doxorubicin and cyclophosphamide (TAC) has shown better efficacy than 5-FU with the same agents (FAC) in terms of disease-free survival and overall survival, in a long term (5 year) randomised controlled trial in women with early breast cancer (BCIRG001 trial). Considering the cost difference between the two regimens and the potentially large number of patients affected by this new indication, an economic assessment was deemed necessary. METHODS: In order to assess long term costs and effectiveness of both regimens beyond the time scope of the trial, we developed a lifetime Markov model comparing TAC and FAC. Four health states were defined: alive without relapse, alive with loco-regional relapse, alive with distant relapse and dead. Transitions occurred every 6 months accordingly to time dependent transition probabilities derived from the clinical trial. Model consistency was checked against the 5-year trial results. We took into account costs of initial chemotherapy, of severe (grade 3/4) adverse events (febrile neutropenia, stomatitis, diarrhoea, infection), of secondary prophylaxis with growth factors and of follow-up after treatment. In case of relapse, a cost was assigned to patients including pre-treatment check-up, chemotherapy, supportive care and follow-up. The perspective was that of the French public health insurance. RESULTS: Patients receiving TAC had a longer life expectancy than those treated with FAC (28.61 versus 26.33 years). Overall lifetime average costs were 20,837€ and 16,143€ respectively for TAC and FAC. The incremental cost-effectiveness ratio (ICER) was 2,059€ in the base case, varying from 1,474€ to 4,963€ according to the multi-ways sensitivity analysis. CONCLUSION: The economic assessment shows that TAC is cost-effective in the management of early breast cancer in France with an ICER below the threshold commonly cited in such analyses.