Reliability of Kaiser Score in Assessing Additional Breast Lesions Identified on Staging MRI in Patients with Breast Cancer

Abstract

(1) Background: The Kaiser score is a user-friendly tool that evaluates lesions on breast MRI and has been studied in the general population and a few specific clinical scenarios. We aim to evaluate the performance of the Kaiser score in the characterization of additional lesions identified on staging breast MRI. (2) Methods: The Kaiser score of the biopsied additional lesions identified on staging MRI in recently diagnosed breast cancer patients was retrospectively determined. Statistical analysis was performed to evaluate the diagnostic capability of the Kaiser score and whether it is affected by different imaging and pathological parameters of the additional and the index lesion. (3) Results: Seventy-six patients with ninety-two MRI-detected lesions constitute the studied population. There was a statistically significant difference in the Kaiser score between benign and malignant lesions, irrespective of the pathology of the index cancer (p = 0.221) or the size and the imaging features of the additional lesion. Using a cutoff of 5 and above for suspicious lesions, biopsy could have been avoided in 34/92 lesions. (4) Conclusions: The Kaiser score can assist radiologists in the evaluation of additional MRI lesions identified in recently diagnosed breast cancer patients, thus decreasing the number of unneeded biopsies and delays in definitive surgical management.

Keywords: Kaiser score; Tree flowchart; additional cancer; breast cancer; staging breast MRI.

Figure 1

Distribution of MRI-detected additional lesions as cancer vs. noncancer.

Figure 2

AUC for the Kaiser score as a predictor for breast cancer.

Figure 3

True negative case of a 47-year-old patient with a recent diagnosis of left breast cancer. Staging breast MRI shows clumped non-mass enhancement (circle) in the contralateral breast with a Kaiser score of 2. MRI guided biopsy was performed yielding proliferative fibrocystic changes.

Figure 4

False negative case of a 55-year-old woman with recently diagnosed ductal carcinoma in situ (DCIS) in the lower outer quadrant of the right breast. An additional tiny linear non-mass enhancement is identified in the lower inner quadrant of the ipsilateral breast (circle), showing a Kaiser score of 1. MRI-guided biopsy was performed yielding DCIS.

Figure 5

True positive case of a 37-year-old woman with recently diagnosed IDC in the central aspect of the right breast (arrow). An additional small irregular enhancing mass is identified in the lower outer quadrant of the contralateral breast (circle), showing a Kaiser score of 9. MRI-guided biopsy was performed yielding DCIS.

Figure 6

False positive case of a 25-year-old woman with recent diagnosis of locally advanced left breast cancer. Staging breast MRI shows an irregular mass (circle) in the contralateral breast showing some spiculations and exhibiting washout kinetics. The Kaiser score of this lesion was 9. A biopsy was performed showing intraductal papilloma and sclerosing adenosis.