Open Access Research article

Prevalence of molecular subtypes and prognosis of invasive breast cancer in north-east of Morocco: retrospective study

Sanae Bennis13*, Fouad Abbass2, Yousra Akasbi4, Kaoutar Znati3, Khalid Amrani Joutei2, Omar El Mesbahi4 and Afaf Amarti13

Author Affiliations

1 Department of Pathology, Laboratory Biology of cancers-Faculty of Medicine & Pharmacy, Hassan II University Hospital Fez, Km 2.200 Route de Sidi Harazem, Fez, Morocco

2 Faculty of Sciences and Technology, Fez, Morocco

3 Department of Pathology, Hassan II University Hospital, Fez, Morocco

4 Medical Oncology unit, Hassan II University Hospital, Fez, Morocco

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BMC Research Notes 2012, 5:436  doi:10.1186/1756-0500-5-436

Published: 13 August 2012

Abstract

Background

Breast carcinoma is known as a heterogeneous disease because gene expression analyses identify several subtypes and the molecular profiles are prognostic and predictive for patients. Our aim, in this study, is to estimate the prevalence of breast cancer subtypes and to determine the relationship between clinico-pathological characteristics, overall survival (OS) and disease free survival (DFS) for patients coming from north-east of Morocco.

Methods

We reviewed 366 cases of breast cancer diagnosed between January 2007 to June 2010 at the Department of pathology. Age, size tumor, metastatic profile, node involvement profile, OS and DFS were analyzed on 181 patients. These last parameters were estimated by Kaplan-Meier analysis and log-rank test to estimate outcome differences among subgroups.

Results

The average age was 45 years, our patients were diagnosed late (57% stage III, 17.5% stage IV) with a high average tumor size. Luminal A subtype was more prevalent (53.6%) associated with favorable clinic-pathological characteristics, followed by luminal B (16.4%), Her2-overexpressing (12.6%), basal-like (12.6%) and unclassified subtype (4.9%).

Survival analysis showed a significant difference between subtypes. The triple negative tumors were associated with poor prognosis (49% OS, 39% DFS), whereas the luminal A were associated with a better prognosis (88% OS, 59% DFS). The luminal B and the Her2-overexpressing subtypes were associated with an intermediate prognosis (77% and 75% OS, and 41% and 38% DFS respectively).

Conclusion

This study showed that molecular classification by immunohistochemistry was necessary for therapeutic decision and prognosis of breast carcinoma. The luminal A subtype was associated with favorable biological characteristics and a better prognosis than triple negative tumors that were associated with a poor prognosis and unfavorable clinic-pathological characteristics.

Keywords:
Breast cancer; Molecular subtypes; Prognosis; Overall survival (OS); Disease free Survival (DFS)