275P - Efficacy and safety of trastuzumab in small HER2 positive tumors. A single institution experience

Date 01 October 2012
Event ESMO Congress 2012
Session Poster presentation III
Topics Cytotoxic agents
Breast Cancer
Therapy
Biological therapy
Presenter Maria Vita Sano
Authors M.V. Sano1, E. Taibi2, M. Alì2, M. Chiarenza2, S. Clementi2, M. Caruso3, R.A. Aiello2
  • 1Humanitas Centro Catanese di Oncologia, 95121 - Catania/IT
  • 2Medical Oncology, Humanitas Centro Catanese di Oncologia, 95121 - Catania/IT
  • 3Oncologia Medica, Humanitas Centro Catanese di Oncologia, IT-95121 - Catania/IT

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 < 35 years. However some patients with HER2 positive cancers develop a recurrence despite small tumor size (< 2 cm) and none of these factors. Four large trials confirmed the potential benefit of incorporating trastuzumab in adjuvant regimens as a standard treatment. The effectiveness of adjuvant trastuzumab has been demonstrated either for node negative pT1c patients and for diseases at a higher risk. However these trial were not able to provide any information regarding the outcome of patients with node negative tumours <1cm.

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.