1726P - Comparison of Breast Cancer Subtypes between young and elderly women

Date 11 September 2017
Event ESMO 2017 Congress
Session Poster display session
Topics Cancer in Young Adults
Breast Cancer
Geriatric Oncology
Pathology/Molecular Biology
Presenter Ivane Kiladze
Citation Annals of Oncology (2017) 28 (suppl_5): v595-v604. 10.1093/annonc/mdx391
Authors I. Kiladze1, A. Mariamidze1, M. McHedlishvili2, K. Tsomaia2, F. Todua1
  • 1Medical Oncology, Research Institute of Clinical Medicine, 0112 - Tbilisi/GE
  • 2Pathology, TSU, 0160 - Tbilisi/GE

Abstract

Background

Breast cancer(BC) are increasingly recognized as heterogeneous disease based on expression of receptors for estrogen (ER), progesterone (PR), and human epidermal growth factor receptor 2 (HER2). There are four main subtypes of BC with differing tumor characteristics and different risk factors, treatment options and prognoses. Few data exist on the frequency of molecular subtypes in young and older women. The purpose of this study is to compare the distribution of the BC subtypes in young and elderly patients.

Methods

BC during the period 2013 to 2015 including ER/PR and HER2 status, was obtained from the Georgian main histopathology laboratories all over the country. We analyzed 1003 women with BC included 85 women aged 20 to 39 years (YA’s), 118 women aged 40 to 45 years (older premenopausal),665 women aged 46-70 (postmenopausal) and 135women older than 70 years (elderly group) at diagnosis. Incidence rates were calculated by subtype (triple-negative; HR +/HER2 -; HR +/HER2 +; HR -/HER2 +), and differences in subtype characteristics by age groups were evaluated.

Results

The incidence of BC in YA’s was 8,5%. The most common BC subtype was HR +/HER2- among all age groups, and HR -/HER2 + was the least; however, the relative contribution of each subtype varied within age categories. In YA’s HR +/HER2 - was the most commonly diagnosed subtype (62%), followed by HR +/HER2 + (15%), triple-negative (12%) and HR -/HER2 + (11%). Statistically no significant difference of BC subtypes was observed in age groups. HR +/HER2 - subtype was lesser in YA’s than in elder population (62% vs 73%), but statistically non-significant (p = 0.19) and there was not significant difference in prognostically “unfavorable” subtypes (HR-/HER2+ and triple-negative) (23% vs 17%) (p = 0.134; (CI) 95%: 0.09 to 1.71). Surprisingly no difference of Triple-negative BC was observed in YA and elderly groups (12% vs 13%).

Conclusions

The distribution of breast cancer subtypes among young adults didn’t vary from that observed in older women. Our study results seem to be in contradiction with other studies previously reported in literature. Future studies should consider whether distribution of breast cancer subtypes influences long-term survival in young compared with older women.

Clinical trial identification

GYO 02/17

Legal entity responsible for the study

Georgian Group of Young Oncologists

Funding

None

Disclosure

All authors have declared no conflicts of interest.