P2-14-10: Are There Variations in Invasive Tumour Characteristics between Different Ethnic Groups?

Abstract

Abstract Introduction: Studies have shown that ethnic minorities with breast cancer are more likely to present at a younger age and with more aggressive tumours. The aim of this study was to examine the variation in tumour characteristics and surgical outcomes in different ethnic groups in our breast unit over a 12-month period. Methods: A retrospective study was performed on all patients with a new diagnosis of breast cancer, either screen-detected or symptomatic, between January to December 2009. Using our Trust databases, data on patient demographics, tumour characteristics, and ethnicity were collected. Where ethnicity was not documented, patients were contacted by telephone to complete the database. Those unable to be contacted were excluded from the study. Other exclusion criteria include those with recurrent ipsilateral breast cancer. Results: A total of 270 patients (265 females) were included in our study, of which 235 (87%) had invasive cancers (ductal carcinoma, lobular carcinoma, tubular carcinoma, mucinous carcinoma, cribriform carcinoma, papillary carcinoma, sarcoma) and the remaining 35 patients (13%) had non-invasive cancers (ductal carcinoma in-situ, lobular carcinoma in-situ, papilloma, columnar cell hyperplasia). We were unable to contact 23 (8.5%) patients to ascertain their ethnicity, and therefore these have been excluded from our results. Table 1. Tumour characteristics and surgical intervention in patients with invasive breast cancer in 2009 Conclusion: We found that the age of breast cancer presentation was lowest in Black and Asian patients (mean age 52 years and 54 years, respectively), compared to White (mean age 59 years). Furthermore, compared to white patients, tumours in Asian patients were larger (62.5% vs 47.2%), of higher grade (83.3% vs 75.2%), more likely to be ER negative (16.7% vs 12.4%), and tended to be lymph node positive (41.7% vs 34.2%). These may explain the higher mastectomy rate in Asian patients (n=12, 50%). The reason for the younger presentation age in the ethnic Asian group is unclear. However, it is possible that their cancer may have different tumour biology. Other studies have suggested reasons such as birth cohort effect and obesity. Reflecting the United Kingdom's population the majority of patients that present to our breast unit are White and the number of Asian patients remains small. An increase in the sample size may strengthen our results. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-14-10.