Clinical, Histopathologic Features and Outcome of Breast Cancer in UK Women of Ethnic Origin.

Objective: Breast cancer (BC) in non-Caucasian females is understudied and its management is based on Caucasian data. 30 % of the West Midlands females are non-Caucasian. We aimed to elucidate the pathologic features, molecular profile, and outcome of non-Caucasian breast cancer.

Methods: Breast cancers (BCs) of different ethnic origins diagnosed at a large Birmingham tertiary referral hospital between 2000 and 2016 were identified. Detailed clinical and histological data were collected and statistically analyzed.

Results: Out of 7554 BC cases, 749 were of ethnic ancestry and median age of 51 years. These comprised 47 in-situ and 702 invasive carcinomas of presenting symptomatically in 86.2% of patients. 53.4% of the invasive carcinomas measured >20 mm. Cancers were predominantly of grade 3 (45%), and grade 2 (42.4%). Median NPI was 4.35. 65.1% of the ethnic carcinomas were of luminal subtype, 18.6% were Her2 positive and 16.2% triple-negative. Median overall survival was 62 months. Five and ten-year survival was 81.7% & 68.4% respectively. Ethnicity correlated with higher NPI (p <0.001), larger tumour size (p= 0.001) and larger number of positive axillary nodes (p=0.007). Negative correlations were found between age at diagnosis and both invasive tumour size & grade (p< 0.001) and between tumour grade and overall survival (p= 0.006).

Conclusion: Compared with Caucasian breast cancer, non-Caucasian tumours presented predominantly symptomatically at younger age, were of larger size, higher grade with more unfavorable phenotypes and shorter survival. This is important in counselling, planning management and follow up of non-Caucasian patients.