Accuracy of FNA Versus CNB of Abnormal Axillary Lymph Nodes in Setting of Invasive Breast Cancer

Ultrasound Guided Core Needle Biopsy Versus Fine Needle Aspiration of Morphologically Abnormal Axillary Lymph Node in Patients With New Diagnosis or Suspected Diagnosis of Invasive Breast Carcinoma

To compare accuracy of ultrasound guided fine needle aspiration (FNA) to core needle biopsy (CNB) of ultrasound detected abnormal axillary lymph nodes in patients with newly diagnosed invasive breast cancer or suspected invasive breast cancer. Hypothesis: FNA and CNB have equivalent diagnostic accuracies In order to prove our hypothesis, we will perform FNA and CNB on the same lymph node in each consented patient. The two samples will be evaluated separately by different pathologists blinded to the material in the other sample. The results of the biopsies will be compared to the gold standard (lymph node excision).

There is only one arm to this study and includes all eligible and consented patients with abnormal axillary lymph node on ultrasound.

Accuracy will be determined by comparing the results of the FNA and CNB performed on the same lymph node to the gold standard using a paired test of equivalence. The gold standard is the final pathologic diagnosis of excised lymph node containing biopsy marker (either sentinel lymph node biopsy or axillary dissection). Surgical excision of pre-operatively sampled lymph node marks the end of study participation for each patient.

Pain associated with each biopsy method will be assessed with a visual analog scale (0- 10) after a baseline pain measurement. The results will be compared to baseline pain level and analyzed using a paired t test.

Inclusion Criteria: Recent or suspected diagnosis of invasive breast cancer with abnormal ipsilateral axillary lymph node Able to provide informed consent Exclusion Criteria: Lymph node not amenable to core biopsy Patient is unlikely to undergo lymph node excision (i.e. elderly patient with co-morbidities)