The Role of Preoperative Magnetic Resonance Imaging in the Assessment and Surgical Treatment of Interval and Screen-Detected Breast Cancer in Older Women.

We describe the relationship between preoperative magnetic resonance imaging (MRI) and the utilization of additional imaging, biopsy, and primary surgical treatment for subgroups of women with interval versus screen-detected breast cancer. We determined the proportion of women receiving additional breast imaging or biopsy and type of primary surgical treatment, stratified by use of preoperative MRI, separately for both groups. Using Breast Cancer Surveillance Consortium (BCSC) data, we identified a cohort of women age 66 and older with an interval or screen-detected breast cancer diagnosis between 2005 and 2010. Using logistic regression, we explored associations between primary surgical treatment type and preoperative MRI use for interval and screen-detected cancers. There were 204 women with an interval cancer and 1,254 with a screen-detected cancer. The interval cancer group was more likely to receive preoperative MRI (21% versus 13%). In both groups, women receiving MRI were more likely to receive additional imaging and/or biopsy. Receipt of MRI was not associated with increased odds of mastectomy (OR = 0.99, 95% CI: 0.67-1.50), while interval cancer diagnosis was associated with significantly higher odds of mastectomy (OR = 1.64, 95% CI: 1.11-2.42). Older women with interval cancer were more likely than women with a screen-detected cancer to have preoperative MRI, however, those with an interval cancer had 64% higher odds of mastectomy regardless of receipt of MRI. Given women with interval cancer are reported to have a worse prognosis, more research is needed to understand effectiveness of imaging modalities and treatment consequences within this group.