Prognostic and predictive value of HER-2/Neu over expression in primary breast cancer

ABSTRACT

To investigate the presence of HER-2 over expression by immunohisto-chemistry in 81 archival breast cancer specimens and its impact on survival in relation to other prognostic factors. Paraffin embedded primary breast cancer specimens from 81 patients with stage I-III breast cancer, treated in Clinical Oncology and Nuclear Meadicine and surgical Oncology Dpartment, Mansoura University Hospital, were studied immuno-histochemically. All patients were subjected to modified radical mastectomy with axillary dissection. Locoregional postoperative radiotherapy was given to all patients with lymph node metastases or primary tumors large than 2 cm located in the medical or central area of the breast. Primenopausal node positive patients were treated with six courses of either CMF or FAC regimens. Postmenopausal node positive patients were given tamoxifen with or without CMF. HER-2neu protein over expression was detected in 28% of tumors. A significant correlation was noted between HER-2 expression, poor histologic grade and higher number of mitosis. Also, HER-2 expression was associated with shorter 5-year over all survival and disease free survival rates compared with HER-2 negative cases [52.8% V 84.8% and 44.8% V 73.9% respectively]. In a multivariate analysis, HER-2 over expression was found to be a significant predictor factor of overall and disease free survival [p=0.004 and 0.01 respectively]. HER-2/nen overxpression is an independent prognostic factor for risk of recurrence. Women with tumours without HER-2 overxpression have a good prognosic; aggressive therapy n this group in therefore difficult to justify. On the other hand, even with adjuvant chemotherapeutic treatment whose tumours exhibit HER-2 over expression have an increased risk of recurrence. Randomized trials to compare more aggressive adjuvant chemotherapy versus standard chemotherapy for women whose tumor exhibit HER-2 protein over expression are recommended