Original scientific paper

Testing tumor type dependent relations between expression of ER and PgR with Ki-67 values in a single series of 1180 invasive ductal cancer patients

Sven Kurbel ; Dept. of Internal Medicine, School of Medicine, Osijek, Croatia
Branko Dmitrović ; Dept. of Pathology and Forensic Medicine, School of Medicine, Osijek, Croatia
Ksenija Marjanović ; Dept. of Pathology and Forensic Medicine, School of Medicine, Osijek, Croatia
Branka Kristek ; Dept. of Radiology, School of Medicine, Osijek, Croatia

Abstract

Background: Model of cancer-associated epigenetic changes (Kurbel S.
Tumour Biol. 2013;34:2011-7) proposes that dysfunctional estrogen receptors (ER), unable to adequately express progesterone receptors (PgR), beside in the ER+PgR– breast cancers might also be present in ER+PgR+ tumors showing weak PgR expression.

Methods: In 1180 patients with invasive ductal cancers, ER and PgR
positivity were semiquantitatively classified in four groups: “0” means no
positive cells; “1+” <10% positive cells; “2+” 11–30% positive cells; and “3+” 31–100% positive cells. Tumors were divided in breast cancer types.

Results: Among patients older than 54, Luminal A and B1 tumors were
frequently ER3+ (p<0.01), while PgR3+ tumors were more common among Luminal A patients younger than 55 (p=0.034), suggesting that in older Luminal A or B1 patients, high ER and low PgR expression is common. Among Luminal B2 patients, ER and PgR expression did not depend much on age or on their Ki–67 values. The model predicted share of dysfunctional ERs was 7.32% (for Luminal A), 11.26% (B1), 12.62% (B2 & Ki–67<=20%) and 14.73% (B2 & Ki-67>20%). The predicted values matched well with the found shares of
ER3+PgR1+ tumors within these three types (p>0.10).

Conclusions: The results support heterogeneity among ER+PgR+ tumors.
Future studies of ER+PgR+ phenotype variants are required since hypothetical dysfunctional ERs in some ER+PgR+ breast cancer patients might alter their endocrine treatment outcomes.

Keywords

Hrčak ID:

138310

URI

https://hrcak.srce.hr/138310

Publication date:

30.12.2014.

Visits: 1.230 *