BRCA1/2 Mutations and Outcomes Among Middle Eastern Patients with Early-Onset Breast Cancer in Oman

Al Amri, Waleed, Al-Amri, Ahmed, Al Abri, Aisha, Hughes, Thomas A ORCID: https://orcid.org/0000-0003-1169-3386 and Al Lawati, Fatma (2024) BRCA1/2 Mutations and Outcomes Among Middle Eastern Patients with Early-Onset Breast Cancer in Oman. The Oncologist. (In Press)

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Abstract

Background: High prevalence of Early-Onset Breast Cancer (EOBC) has been reported in Middle Eastern populations. For example, in Oman more than 50% of BC patients are under age 45 at diagnosis. Causes for this high incidence are unknown. Germline BRCA gene mutations have been associated with EOBC, however, prevalence of these mutations and how they relate to EOBC in Oman has not been assessed.

Patients and Methods: Clinical data were collected for BC patients treated at Royal Hospital, Oman between 2010-22. Germline BRCA1/2 gene mutations were identified using sequencing and MLPA. Correlation and Kaplan-Meier survival analyses were performed to test relationships between clinico-pathological features, gene mutations and outcomes.

Results: Total of 1336 middle eastern BC patients were included; 611 were aged <45 at diagnosis (45.7%). No significant correlation was found between BRCA1/2 mutation status and EOBC (p=0.229), and the majority of EOBC cases had no family history of BC. EOBC tumours did, however, differ in clinicopathological features; EOBCs were significantly larger (p<0.0001), of higher grade (p<0.0001), and included more HER2-enriched, and triple negative subtypes (p=0.018) compared with later onset cases. Accordingly, survival analyses revealed that EOBC had significantly worse disease-free survival (p=0.002). BRCA gene variants showed a distinct range of mutations including, in BRCA2, three previously unreported mutations and four potential founder recurrent mutations.

Conclusion: Our findings showed that germline BRCA1/2 mutations were not over-represented in EOBC cases in Oman, and therefore are unlikely to be responsible for high EOBC rates.

Item Type:	Article
Status:	In Press
Subjects:	Q Science > Q Science (General)
School/Department:	School of Science, Technology and Health
URI:	https://ray.yorksj.ac.uk/id/eprint/10368