To assess the economic impact of the introduction of trastuzumab and lapatinib, as 1st and 2nd line treatment of HER-2 (Human Epidermal Growth Factor Receptor 2)-positive mBC (metastatic breast cancer) patients in Veneto region (North-East of Italy).

A Markov state decision model was implemented to evaluate the cost impact of trastuzumab and lapatinib use for a lapse of time of three years in Veneto public hospitals. The Markov model expressed transition probabilities from three different states, comparing in addition the expected deaths and the monthly survival rates in treatment and notreatment groups, along the lines of previously published studies.

From the initial cohort of 267 patients eligible for treatment, stable ones (195) were considered in order to evaluate the impact of the targeted therapy on overall progression of the disease. Trastuzumab administration accounted for a regional expense of 2765662 € within the 6 months, almost duplicating in 1 year. 2^nd line therapy accounted on the 6 months budget for almost 100000 €, costs overseen for the eligible patients at the beginning. All costs were considered together with the associated drug. Costs of second line treatment increased within the last year, taken the higher number of patients transiting from a stable condition to a progressive one.

Our result pointed out that mBC represents a considerably high cost also from a regional perspective. Economic evaluations are usually performed in different countries at national level, while in local health care decision making there is lack of health economic data and evaluations.