MRI findings in women with triple negative breast cancer.

Abstract

Abstract Abstract #4014 Background
 Preoperative magnetic resonance imaging (MRI) of the breasts in women with breast cancer (BC) has improved the detection of occult ipsilateral (I/L) and contralateral (C/L) malignancies. Breast MRI findings in patients with estrogen receptor (ER), progesterone receptor (PR), and HER2 negative (triple negative (TN)) disease have not been previously reported. Women with TN BC are at increased risk of distant metastases and a reduced survival vs. BC patients as a whole. One potential explanation may be the presence of occult disease. The role of bilateral breast MRI in these patients remains to be determined.
 Hypothesis
 Patients with TN BC are more likely to have occult malignancy identified by preoperative MRI vs. those with non-TN BC.
 Methods
 All newly diagnosed BC patients from 2003-2007 were reviewed. Information on age, race, histology, ER, PR, HER2, staging, treatment, MRI findings, subsequent investigations, and additional cancer diagnoses was recorded. The incidence of additional I/L or C/L malignany was calculated. The percentage of total patients initially felt to be candidates for partial breast irradiation who required a change in their cancer management was calculated.
 Results
 55 (11%) were diagnosed with TN BC, of whom 52 women completed preoperative MRI. 456 (89%) had non-TN BC; 421 completed preoperative MRI. The median age among TN and non-TN patients was 62 years (Table 1). A majority of women in both groups were Caucasian. African-American women were more likely to be diagnosed with TN vs. non-TN disease (11% vs. 6%).
 
 I/L BC was documented in 13/52 (25%) of TN patients vs. 25% of non-TN patients. No C/L cancers were detected in the TN group (6% in the non-TN group). Of the TN group, 15 patients required a change in their treatment (29%) based on findings from MRI vs. 32% of non-TN patients.
 Conclusions
 Patients with a new diagnosis of TN BC are not at increased risk of occult malignancy than those with non-TN BC. 25% of patients with TN BC had additional I/L disease not previously detected on clinical examination, mammogram, or ultrasound. Of those with non-TN BC, 25% were diagnosed with an additional I/L and 6% with C/L malignancy. The benefit of MRI was limited by false positives, with a number of patients in both groups undergoing a benign biopsy.
 These results suggest that patients with TN BC are not more likely than those with non-TN disease to have additional occult I/L or C/L cancer. The incidence of additional disease remains high and preoperative MRI may be beneficial. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4014.