DOES THE EI/B-MODE LENGTH RATIO PREDICT BREAST CANCER TUMOR GRADE?

1. DOES THE EI/B-MODE LENGTH RATIO PREDICT BREAST CANCER TUMOR GRADE? Joseph R. Grajo, MD* Cynthia Peterson, MPH, RDMSRichard G. Barr, MD, PhD

2. Elastography • Has shown potential to differentiate benign and malignant breast lesions with high sensitivity and specificity

3. Elastography Techniques • This study utilizes compression elastography • Varying methods include • Change in length • Change in area • Color elastography • Strain ratio measurements • In our lab we choose to use grey scale imaging and length change ratios.

4. Previous Work • We previously reported a sensitivity of 99% and specificity of 85% in a multicenter study of 635 biopsy-proven lesions • Average E/B ratios were 0.76 for benign lesions (range 0.2 to 1.5) and 1.45 for malignant lesions (range 1.0 to 3.1)

5. Hypothesis • In reviewing various pathologies from our series, we noticed that more aggressive malignancies demonstrated larger E/B ratios • We hypothesized that the degree of length change correlates with tumor grade

6. Methods • Equipment • Siemens Antares Ultrasound System • Siemens S2000 Ultrasound System • Philips IU22 Ultrasound System • Simultaneous, side-by-side display of B-mode and elasticity images • “shadow” or “copy” functions used to measure at same location

7. Methods • We evaluated 134 malignancies diagnosed in 125 patients referred for ultrasound guided core biopsy utilizing a 10 or 13 Hz probe over a 3 year period. • Measurements were made at the time of the clinical examination by the Radiologist performing the study. • Biopsies were subsequently performed with a 14 g Vacuum assisted core needle. FNAs were not included.

8. Methods • In patients with pre-malignant or malignant diagnoses, pathology reports were reviewed for staging • If the tumor was excised, grading was based on the surgical specimen

9. Methods • Mean E/B ratio of the tumor and the pathology were recorded for each lesion • E/B ratio of the tumor was compared to Scharf-Bloom-Richardson (SBR) and intraductal carcinoma grade using Pearson correlation coefficient

10. Scharf-Bloom-Richardson Grading • Tubule Formation • > 75% = 1 • 10-75% = 2 • < 10% = 3 • Nuclear Pleomorphism • Small, uniform cells = 1 • Mod inc size/variation = 2 • Marked variation = 3 • Mitosis Count • Up to 7 = 1 • 8 to 14 = 2 • 15 or more = 3 3, 4, 5 = Low Grade 6 or 7 = Medium Grade 8 or 9 = High Grade

11. Results • Average patient age was 64 years old (range 36-95) • E/B ratios varied from 1.0 to 3.1 • Pathology • Pre cancerous lesions 2 • Mucinous/colloid 7 • DCIS 13 • IDC 101 • Grade 1 30 • Grade 2 45 • Grade 3 26 • Lobular 11

13. Results

14. IDC Results • E/B ratio as compared to the tumor grade in IDC using one-tailed Pearson correlation coefficient (p < 0.05) was 0.078. • E/B ratio as compared to the SBR grade in IDC using one-tailed Pearson correlation coefficient (p < 0.05) was significant at 0.040.

15. Conclusion • In this small study, E/B ratio correlates with the aggressiveness of breast tumors • In Invasive Ductal Cancers, there is a trend for increased E/B ratio with tumor grade, which was statistically significant • Other aspects and characteristics of the EI image may provide additional diagnostic information not yet recognized