364P - Immunohistochemical predictors of the clinical and pathological response to neoadjuvant chemotherapy in locally advanced breast cancer

Date 29 September 2012
Event ESMO Congress 2012
Session Poster presentation I
Topics Breast Cancer, Locally Advanced
Pathology/Molecular Biology
Presenter Maria Rodionova
Authors M. Rodionova1, D. Ryabchikov1, S. Portnoy2, I. Vorotnikov3, N. Chkhikvadze3
  • 1Breast Cancer Department, N. N. Blokhin Russian Cancer Research Center, 115478 - Moscow/RU
  • 2Department Od Female Reproductive System Carcinomas, N.N.Blohkin Cancer Research Center, 115478 - Moscow/RU
  • 3Breast Cancer Department, N.N. Blokhin Russian Cancer Research Center, 115478 - Moscow/RU

Abstract

Purpose

To determine predictive immunohistochemical characteristics of the tumor correlated with the response to neoadjuvant chemotherapy in patients with locally advanced breast cancer.

Material and methods

A prospective study of 87 breast cancer patients (Т2-4N0-M0) treated in N.N.Blokhin Russian Cancer Research Center 1997 - 2009. Tumor samples were taken prior to neoadjuvant chemotherapy (cor-biosy). Pathological criteria assessed were: histological variant, tumor grade, HR and Her-2/neu status, Ki67 expression and glycoprotein Pgp-170 status. After 4-6 cycles of chemotherapy all the patients underwent radical surgery. We quantified the response clinically and pathologically (Lavnikova's system of therapeutic pathomorphism evaluation).

Results

The experimental results showed the following response rates: complete response – 11 (12.6%), partial response – 54 (62.1%), stable disease – 21 (24.1%) patients. One patient had progression of the disease. Stable disease correlated significantly with positive Pgp-170 status (41.7% vs. 17.7%, р = 0.04), whilst negative Pgp-170 – with objective response (82.4% vs. 54.2%, р = 0.02). Pathomorphism was achieved as follows: lack of pathomorphism - 10(11.5%), first-degree pathomorphism 17(19.5%), second-degree – 28(32.2%), third-degree – 18(20.7%), fourth-degree – 14(16.1%). Rare histological variants had more often third-degree pathomorphism than ductal carcinoma (р = 0.02); G1 had more often fourth-degree pathomorphism than G2 (p = 0.002); high-degree pathomorphism was more frequently observed in patients with N2 status than with N0 (p = 0.006) and N1 (p = 0.009). Her-2/neu + tumors showed lower degree of pathomorphism that those with HR status (23.7% vs. 45.6%, р = 0.03). Pgp 170+ tumors had significantly more often no (p = 0.004) or first-degree pathomorphism (p = 0.004), and as a result – lower rate of high degree pathomorphism than in Pgp-170 negative tumors (12.5% and 47.1%, respectively).

Conclusions

Some pathological and immunohistochemical characteristics of the tumor can be assessed preoperatively and predict the likelihood of the clinical and pathological response to neoadjuvant chemotherapy.

Disclosure

All authors have declared no conflicts of interest.