Disease Free Survival among Molecular Subtypes of Early Stage Breast Cancer between 2001 and 2010 in Iran

Behrouz Najafi,Saeid Anvari,Zahra Atrkar Roshan

doi:10.7314/apjcp.2013.14.10.5811

Behrouz Najafi, Saeid Anvari + Show 1 more

Open Access

https://doi.org/10.7314/apjcp.2013.14.10.5811

Copy DOI

Abstract

Breast cancer is the most common cancer among women. Molecular subtypes are important in determining prognosis. This study evaluated five-year disease-free survival among four molecular subtypes in patients with early stages of breast cancer. In this retrospective descriptive-analytical study, information on patients with breast cancer between 2001-2010 was evaluated. Five hundred ninety two patients in the early stages of breast cancer (stages 1 and 2) were selected to undergo anthracycline-based chemotherapy. Relapse, death or absence (censor) were considered as the end of the study. Patients based on ER, PR and HER-2 expression were divided into four subtypes (luminal A, luminal B, HER-2 enriched and triple negative). Information based upon questionnaire was analysed. To show the patients survival rate, life table and Kaplan-Meyer methods were used, and for comparing mean survival among different groups, the Log-Rank test was utilized. Mean age at diagnosis was 47.9±9.6. Out of the 592 patients, 586 were female (99%) and 6 were male (1%). Considering breast cancer molecular subtypes, 361 patients were in the luminal A group (61%), 49 patients in the luminal B group (8.3%), 48 patients in the HER-2 enriched group (8.1%) and 134 in the triple negative group (22.6%). Mean disease-free survival was 53.7 months overall, 55.4 months for the luminal A group, 48.3 months for the luminal B group, 43 months for the HER-2enriched group and 54.6 months for the triple negatives. Disease free survival differed significantly among the molecular subtypes (p value=0.0001). The best disease-free survival rate was among the luminal A subgroup and the worst disease-free survival rate was among the HER-2 enriched subgroup. Disease free survival rate in the HER-2 positive groups (luminal B and HER-2 enriched) was worse than the HER-2 negative groups (luminal A and triple negative).

Highlights

Breast cancer is the most prevalent cancer among women and the second leading cause of cancer death in women and the major cause of death among women between 40-59 years old (Siegel et al, 2011)
The main breast cancer subtypes are due to different genetic expression patterns.In the molecular classification as well as the conventional use of nuclear grading, pathology, immunohistochemical analysis of the hormone receptor and overexpression of epidermal growth factor receptore (HER-2), differentiation in gene expression are used for determining breast cancer, which the results would constitute the major subtypes specification
In our study luminal A group was seen at an older age and triple negative group was seen at a younger age

Summary

Introduction

Breast cancer is the most prevalent cancer among women and the second leading cause of cancer death in women and the major cause of death among women between 40-59 years old (Siegel et al, 2011). The sixth subtype of breast cancer is defined as low claudin which is determined and characterized by low or no expression of cell-cell epithelial adhesion genes (claudin 3, 4, 7 and cadherin E), differentiated luminal cell surface markers (MUC-1, EpCAm) and large amount of mesenchimal to epithelial differentiation markers,cancer immune receptor genes and stem cell like factor (ALDH1A1), CD24, CD44. These subtypes are significantly different in prognosis and response to treatment targets (Prat et al, 2010). A similar process is utilized for diagnosing of HER-2 protein molecules on the cell membrane (King and Greene, 1984; Layfield et al, 1998)

Materials and Methods

Results

Discussion