Prevalence and prognosis of molecular phenotypes in breast cancer patients by age: a population-based retrospective cohort study in western Algeria

Abstract

Introduction: breast cancer is related to age. The young age remains a controversial issue as a prognostic factor and have more aggressive clinical behavior with poor outcome. We aimed for the first time in Algeria to explore on a large cohort of patients the prevalence of the molecular phenotypes and to describe their clinical characteristics and survival.

Methods: medical record of 1140 Algerian patients were analysed and categorized into three age groups: "young" when women were aged below 40 years; "middle-age" when women were aged from 41 to 54 years old and "elder" when women were over 54 years. Baseline categorical variables were analysed using the Chi-square test and survival curves were constructed using Kaplan Meir method.

Results: the distribution of the various prognostic factors did not differ significativelly by age groups except for histological types, hormone receptors status and molecular phenotypes. Most patients were luminal A, indeed, young and intermediate age patients were most likely to be luminal A whereas the aged patients were triple negative with the highest mean DFS. Elsewhere young women are considered as human epidermal growth factor receptor 2 (HER2+) or triple negative molecular subtypes involving more rigorous therapeutic monitoring. The high rate of triple negative breast cancer in aged patients may due to genetic predispositions.

Conclusion: this study sheds light on the histoclinical and molecular characteristics of breast cancer in young patients, which has a good prognosis than their older counterparts. Our results are therefore surprisingly different from what the literature suggests. A further study should understand this uncommon finding.