4.5: Diagnosing breast cancer in a high-risk cohort

Introduction

MRI is a common method for detecting breast cancer in women at high risk [1, 2] These women may instead be diagnosed mammographically or present symptomatically. The aim of this study was to investigate how breast cancer is diagnosed in high-risk women and determine whether there are specific characteristics related to the type of presentation.

Methods

A total of 125 high-risk patients with 134 breast cancers (69 BRCA, 65 family history) were managed at the Royal Marsden Hospital from 1994 to 2013. Following ethical approval, data were collected retrospectively for each presentation of breast cancer: method of presentation/diagnosis (MRI, mammography, symptomatic), age at diagnosis, cancer type, grade, size, presence of DCIS, lymphovascular invasion (LVI), nodal status and tumour subtype. Chi-squared and ANOVA analyses determined any association between the parameters, P < 0.05 was significant.

Results

Ten breast cancers were MRI detected, 43 mammography detected and 81 symptomatic (mean age 41, 51, and 45 years (P = 0.008); mean size 17, 29, and 34 mm (P = 0.076) respectively).The majority of cancers were high-grade (68%) invasive ductal carcinomas (78%) without LVI (76%). MRI-detected cancers were triple negative in 60% (P = 0.03), node negative in 100% (P = 0.005) with DCIS in 70% (P = 0.007). Mammography-detected cancers were luminal in 77% (P = 0.03), node negative in 77% (P = 0.005), with DCIS in 81% (P = 0.007). Symptomatic cancers were luminal in 54%, triple negative in 41%, node negative in 56% and DCIS positive in 51%.

Conclusion

In this high-risk cohort, MRI detects small, triple-negative, node-negative cancers in younger women, while mammography detects larger, luminal, cancers in older women that may be node positive.