PERTRAS observational study: clinical and economic analysis of trastuzumab plus neoadjuvant pertuzumab in women with HER-2 positive breast cancer. [Studio osservazionale PERTRAS: analisi clinica ed economica di trastuzumab più pertuzumab neoadiuvante in donne con carcinoma mammario HER-2 positivo]

Background. Patients with HER-2 positive breast cancer treated with neoadjuvant co-administration of trastuzumab plus pertuzumab were analyzed to evaluate the adjuvant drugs expenditure and the pathologic complete response (pCR) rates in relation to tumor characteristics. Materials and methods. All patients diagnosed with HER-2 positive breast cancer treated with the neoadjuvant anti-HER-2 double blocker trastuzumab plus pertuzumab from January 1, 2018 through August 31, 2023 were extracted from company databases. Results. The sample size was 33 female patients, 25 patients achieved pCR while 8 no pCR, and one patient died. Furthermore, pCR was evaluated according to hormone receptors state, menopausal condition, MIB-1 rate, grading, and tumor staging. The average costs of neoadjuvant and adjuvant therapies on the 33 patients were analyzed, the total costs of which were € 740.094,57. The cost of the neoadjuvant setting was € 11.860,49, the cost of 14 cycles of complete adjuvant therapy for pCR was € 2.074,32, and for no pCR was € 42.986,72. The patient who subsequently died, having completed only 12 cycles of adjuvant setting, generated an expenditure of € 36.845,76. Conclusions. This study shows that most patients (76%) treated with neoadjuvant trastuzumab plus pertuzumab reach pCR and, for these, the cost of adjuvant treatment is less expensive than for patients not reaching pCR.