Background:Breast cancer is currently the leading cause of cancer morbidity and mortality among Algerian women. The aim of this study was to analyze the different proportions and distribution of breast cancer molecular subtypes and to determine their associations with some clinical and pathological characteristics in women from the Aures region. We also screened for the prevalence of BRCA1 germline mutations in HBOC patients.

Materials and Methods: Clinical and tumor characteristics data of 1144 breast cancer patients were collected from cancer registry of anticancer center of Batna. Breast cancers were diagnosed between 2011 and 2015. 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-) and HER2+ (ER-, PR-, HER2+). We also compared patients with TNBC and those with other breast cancer subtypes. Differences between the two groups with regard to clinicopathologic parameters: age at diagnosis, menopausal status, histological type, histological grade, breast feeding and oral contraception were examined using Chi square test. BRCA1 was screened by PCR direct sequencing in 22 HBOC patients including all exons where a mutation was previously found in Algerian population (exons 3, 5, 11).

Results: The mean age at diagnosis cancer was 48.5 years. Proportions of luminal A, luminal B, TNBC and HER2+ breast cancer subtypes were 47.29%, 21.94%, 21.24% and 9.52%, respectively. We noted a significant difference in the distribution of age at diagnosis among the four cancer subtypes (P = 0.04). 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. Our data showed significant differences between premenopausal and postmenopausal status (P=0.00) and tumor histological grade (P<0.03) between TNBC and non TNBC patients. The proportion of premenopausal status was higher in TNBC and non TNBC. Among tumor with histological grade III, TNBC accounted for 33.33% for all TNBC patients and non TNBC accounted for 30.23% for all non TNBC patients. The three BRCA1 recurrent mutations c.83_84delTG, c.181T>G and c.798_799delTT have not been detected in our present study.

Conclusion: We report here for the first time, the distribution of molecular subtypes of breast cancer and some clinical and pathological characteristics in a cohort of female breast cancer patients from the Aures region. Interestingly, the proportion of TNBC subtype in women found in our study is similar to African-American breast cancer patients and higher than reported in white women in Europe and America. Further studies are needed to determine the outcome of the different breast cancer subtypes in the Aures region. Large studies of the screening of BRCA1 and BRCA2 genes are on going for the implementation of the genetic testing.

Citation Format: Farid Cherbal, Chiraz Mehemmai, Khadidja Gassi, Abdelmoumene Guedioura, Yosr Hamdi, Wassila Benbrahim, Rabah Bakour. Clinicopathological and molecular study of breast cancer in Algerian women from the Aures region: Data from the anti-cancer center of Batna [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 271. doi:10.1158/1538-7445.AM2017-271