Efficacy and Safety of Trastuzumab in Small HER2 Positive Tumors. A Single Institution Experience

ABSTRACT Background Patients affected by breast cancer with negative lymph-node are considered at high risk if at least one of the following factors is present: tumor size > 2 cm, HR negative, histological and/or nuclear grade 2-3 or age  Purpose To assess the efficacy and safety of trastuzumab in HER2 positive small tumors (pT1 pN0 M0/ stage I). Patients and methods Between January 2005 and February 2012, 88 patients with small (pT1) Her2 positive node negative breast cancers were retrospectively reviewed at our institution. Nine patients(10,2%) were staged pT1a N0, 17(19,3%) pT1b pN0 and 65(73,8%) pT1c pN0. Among them 83(94%) patients were treated with adjuvant anthracyclines regimens for 4 or 6 cycles followed by one year of trastuzumab (52 weeks). Median age at diagnosis was 51,5 years (range 28-73) Fifty-two patients were followed up for at least 1 year, the median follow up was 35 months (range 13–63). The Left Ejection Ventricular Fraction (LEVF) was assessed at baseline and every three months. Results Two patients relapsed; (one lung metastasis during treatment, one local recurrence 13 months after the last dose). An asymptomatic absolute decrease in LVEF by 10% was recorded in three patients. No patients discontinued the treatment. Conclusions The use of trastuzumab in HER2 positive small tumor seems safe and effective. More data should be available for tumors smaller than 1 cm. Disclosure All authors have declared no conflicts of interest.