383P - Comparison of molecular subtypes of breast cancer in women ≤35 years and > 35 years: Does age matter?

Date 27 September 2014
Event ESMO 2014
Session Poster Display session
Topics Cancer in Young Adults
Breast Cancer, Metastatic
Pathology/Molecular Biology
Presenter Atike Erdoğan
Citation Annals of Oncology (2014) 25 (suppl_4): iv116-iv136. 10.1093/annonc/mdu329
Authors A. Erdoğan1, B.S. Karaca2, H. Yasdik2, Z. Surmeli2, U.A. Sanli2, B. Karabulut2, R. Uslu2
  • 1Medical Oncology, Ege University, School of Medicine, 35100 - izmir/TR
  • 2Division Of Medical Oncology, Ege University, School of Medicine,Tulay Aktas Oncology Hospital, 35100 - izmir/TR

Abstract

Aim

Primary objective was to evaluate the impact of age, on determining molecular subgroups and whether the different outcome of patients ≤35 years and ≥35 years of age is related to the diversity of molecular subgroups.

Methods

A total of 216 patients ≤35 years and randomly selected 212 patients of all patients ≥35 years presented to Ege University Faculty of Medicine Department of Oncology between 2000 and 2011 diagnosed with breast cancer were enrolled in the study. Demographic data, clinico-pathological characteristics and treatment modalities were reviewed and recorded for each patient. Molecular subtyping was based on estrogen, progesteron receptors (ER, PR), cerb-B2 and Ki-67 proliferation index. Luminal A disease was defined as ER (+), PR (+), cerb-B2(-), Ki-67 ≤ %15. Cases that were ER/PR (+), cerb-B2 (-)/(+), Ki-67 ≥ %15 were classified as Luminal B. If all three receptors were negative, then it was accepted as triple negative disease and Her-2 positive disease was characterized by lack of hormon receptors and presence of cerb-B2.

Results

166 of 216 patients ≤35 years of age, and 154 of 212 patients ≥35 years were found to be appropriate and pathologically have been assessed for molecular subtyping. Accordingly, 87 patients (%40.3) in younger group were Luminal B and 32 patients (%14.8) were triple negative, which composed the largest proportion of all very young group. 29 patients (%13.4) were Luminal A, 18 patients (%8.3) were Her-2 positive. Among the ≥35 years group the majority was Luminal B (%28.3) as similar in very young population,however followed by Luminal A (%22.6) that has favorable prognostic features. 28 patients (%13.2) were triple negative, 18 patients (%8.5) were Her-2 positive. There was no statistically significant difference in molecular subtypes between the two age groups. However, triple negative subtype and Ki-67≥ %15 which is associated with poorer prognosis was numerically higher among ≤ 35 years group.

Conclusions

In our study there was no statistically significant difference in molecular subtypes between two diverse age groups. This could be explained by small size of the study population, but also could be an indication that age is an independent prognostic factor apart from all other clinico-pathologic features. Further studies based on genotypic analyses with larger patient series are required.

Disclosure

All authors have declared no conflicts of interest.