02 May Breast Cancer: Pre-Operative Axillary Ultrasound Useful Despite Obesity
MedicalResearch.com: What are the main findings of the study?
Dr. Hieken: Among more than 1,300 newly diagnosed invasive breast cancer patients, 36 percent of whom were obese (BMI ≥ 30), preoperative axillary ultrasound with fine needle aspiration biopsy of suspicious lymph nodes identified metastasis to the lymph nodes in 36 percent of patients found to be node-positive at operation. For all BMI categories (normal, overweight, obese) axillary ultrasound was predictive of pathologic nodal status (p<0.0001). The sensitivity of axillary ultrasound did not differ across BMI categories while specificity and accuracy were better for overweight and obese patients, respectively, than for normal weight patients. Furthermore, patients across all BMI categories who had suspicious axillary lymph nodes on ultrasound and had a positive fine needle aspiration biopsy had significantly more positive lymph nodes at operation, an average of five metastatic nodes, and an overall higher nodal disease burden at operation.
MedicalResearch.com: Were any of the findings unexpected?
Dr. Hieken: We thought that axillary ultrasound might be less accurate in obese patients, because of theoretical concerns regarding technical challenges reported with other soft tissue ultrasound applications in these patients and because of obesity-related alterations in lymph nodes that may complicate imaging findings. However, axillary ultrasound was actually slightly better, largely because a negative axillary ultrasound (normal appearing lymph nodes) was more often associated with negative axillary sentinel nodes at operation in obese than in normal weight patients.
MedicalResearch.com: What should clinicians and patients take away from your report?
Dr. Hieken: Clinicians should be reassured that preoperative axillary ultrasound in newly diagnosed breast cancer patients is an accurate test for preoperative lymph node staging in normal, overweight and obese breast cancer patients. This can help frame patient expectations regarding the likelihood and extent of involved lymph nodes at operation and help with collaborative decision-making regarding selection of treatment options.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Dr. Hieken: Validation of our findings in a prospective analysis. Further work to improve the overall accuracy for all patients of preoperative imaging to stage the axilla for breast cancer patients.
Citation: Abstract Presented at:
American Society of Breast Surgeons annual meeting 2014
Does Patient BMI Affect the Accuracy of Preoperative Axillary Ultrasound in Breast Cancer Patients?
Anushi R. Shah1, Katrina N. Glazebrook2, Judy C. Boughey1, Tanya L. Hoskin3, Sejal S. Shah4, Bergquist R. John1, Sean C. Dupont1, Tina J. Hieken1
1Surgery, Mayo Clinic, Rochester, Minnesota, United States, 2Radiology, Mayo Clinic, Rochester, Minnesota, United States, 3Biomedical Statistics and Bioinformatics, Mayo Clinic, Rochester, Minnesota, United States, 4Pathology, Mayo Clinic, Rochester, Minnesota, United States