Survival and clinicopathological characteristics of breast cancer patient according to different tumour subtypes as determined by hormone receptor and Her2 immunohistochemistry. A single institution survey spanning 1998 to 2010

Abstract

As far as recent breast cancer molecular subtype classification is concerned, much work has dealt with clinical outcomes for triple negative and Her2 patients. Less is known about the course of patients in the remaining subtypes. Molecular classification based on immunohistochemistry is widely available and correlates well with genetic microarray assessment, but at a lower cost. The aim of our investigation was to correlate immunohistochemical subtypes of breast cancer with clinical characteristics and patient outcomes. Since 1998, 1167 patients operated for 1191 invasive breast tumours were included in our database. Patients were regularly followed up until March 2010. Disease-free survival, overall mortality, and breast cancer-specific mortality at 5 years were calculated for the cohort. 72% of tumours were ER+PR±HER2- group, 13% triple negative (ER-PR-HER2-), 10% ER+PR±HER2+ group, and 5% Her2 (ER-PR-HER2+). Cancer-specific survival was 94.2% for the ER+PR+HER2- subtype, 84.8% for the Her2 subtype, 83.3% for the ER+PR-HER2- subtype, and 78.6% for triple negatives. Distant metastases prevalence ranged from 7% to 22% across subtypes, increasing stepwise from ER+PR+HER2-, ER+PR+HER2+, ER+PR-HER2-, ER+PR-HER2+, ER-PR-HER2+ through triple negative. Small, low-grade tumours with low axillary burden were more likely to belong to the ER+PR±HER2- group. Conversely, larger high-grade tumours with significant axillary burden were more likely to belong to Her2 or triple negative groups. ER+PR±HER2- group patients with negative PR receptors performed more like Her2 or triple negative than like the rest of ER+PR±HER2± groups patients. Molecular classification of breast tumours based only on immunohistochemistry is quite useful on practical clinical grounds, as expected. ER+PR±HER2- group patients with negative PR receptors seem to be at high risk and deserve further consideration.

Breast Cancer Recurrence According to Molecular Subtype

“…In the present study, the non-luminal HER2-positive group did not tend to show a marker for contralateral breast cancer, in contrast to the aforementioned study. In terms of distant metastasis, the results of the present study were not in agreement with those of the earlier study, which reported that the non-luminal HER2-positive and triple negative subtypes were associated with a high risk of recurrence, rather than the luminal subtypes (García Fernández et al, 2012). There were no statically significant differences between the non-luminal HER2-positive subtype and the other subtypes, except for the luminal A subtype, despite our having observed that the non-luminal HER2-positive subtype was associated with a higher rate of distant metastasis than the other subtypes.…”

“…In contrast to the results of the present study, the study found that the triple negative subtype was an independent predictor of distant metastasis with statistical significance. García Fernández et al (2012) observed in a large cohort study that luminal tumors had a significantly smaller chance of distant metastasis than nonluminal HER2-positive and triple negative tumors.…”

Expression of Breast Cancer Subtypes Based on the Most Important Biomarkers: Comparison of Clinicopathological Factors and Survival

“…Overall, there has been increasing attention to new molecular classifications of BC, based on the genetic map (3,(34)(35)(36)(37)(38)(39)(40)(41)(42)(43), which can improve the prognostic power with low cost and high accessibility. In fact, IHC classification can improve the prognostic and therapeutic approaches (3,44).…”

“…Breast cancer (BC) is one of the most commonly diagnosed cancers among women worldwide (1)(2)(3). The prevalence of BC is increasing in both developed and developing countries (4), accounting for 19% -34% of all cancer cases among women around the world (5).…”

“…Molecular profiling distinguishes major BC subtypes, which are often determined via immunohistochemical (IHC) analysis of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) (10,12,13). These biomarkers are used to classify BC into at least 5 main groups, based on their molecular characteristics: luminal cell-like tumors (subdivided into luminal A and B), basal cell-like (BCL) or triple-negative phenotypic (TNP), Erb-B2, Copyright (3,14).…”