BACKGROUND: Breast cancer is currently the leading cause of
cancer morbidity and mortality among Algerian women. Molecular classification of
breast cancer is an important factor for prognosis and clinical outcome.
There are limited data regarding molecular breast cancer subtypes among
Algerian women. The objective of the present study was to analyze the
proportion and distribution of molecular subtypes and to determine their
associations with some clinical and tumor characteristics: age at diagnosis,
menopausal status, histological type and histological grade.
MATERIALS AND METHODS: The study population included 3014 female breast cancers.
We analyzed breast cancers from cancer registries of academic medical oncology service of
public hospital of Rouiba, anticancer center of Blida, and anticancer center
of Batna. Breast cancers were diagnosed between 2008 and 2013. Molecular
subtype classification was done based on immunohistochemical surrogates for
ER (Estrogen receptor), PR (Progesterone receptor) and HER2 (human epidermal
growth factor receptor-2) status obtained from medical records for 3014
breast cancer patients. Breast cancer subtypes definitions were as follow:
Luminal A (ER+ and/or PR+, HER2-), Luminal B (ER+ and/or PR+, HER2+), TNBC (ER-, PR - , HER2-), HER2+ (ER-, PR-,
HER2+). Molecular subtypes
were correlated with the clinicopathological characteristics of the tumors.
RESULTS: The mean age at diagnosis cancer was 48.5 years. Proportions of
the luminal A, TNBC, luminal B and HER2+ breast cancer subtypes were 50.59%,
20.80%, 19.67% and 8.92%, respectively. We noted a significant
difference in the distribution of age at diagnosis among the four cancer
subtypes (P= 0.004). Luminal A, Luminal B, TNBC and HER2+ subtypes
were significantly different by premenopausal and postmenopausal status (P=
0.01). Invasive Ductal Carcinoma was the most common histological type in
all breast cancer subtypes. Tumors with histological grade 2 and 3 were more
common in patients for the four breast cancer subtypes.
CONCLUSIONS: For the first time, we report the distribution of molecular
breast cancer subtypes and their associations with some clinicopathological
characteristics in a large cohort of Algerian women. In our current study,
the median age of diagnosis for all breast cancer subtypes was younger than
the average age in Europe and America. Luminal A was the most common sub-
type
in our patients followed by TNBC. The proportion of luminal A subtype was
lesser than reported in white women with breast cancer in Europe and
America. The proportion of TNBC subtype in Algerian women was higher
compared with Caucasian women of European ancestry. This study will
contribute in developing optimal clinical trial protocols and personalized
management strategies for Algerian breast cancer patients.
