Ultrasound-positive axillary lymph nodes in early breast cancer: can a patient subgroup avoid axillary lymph node dissection? A simple algorithm is suggested.

Introduction: National UK guidelines suggest that axillary lymph node dissection (ALND) is no longer mandatory for selected early node-positive breast cancer patients. Our study aimed to identify patients with early breast cancer and ultrasound (USS)-positive axillary metastasis who possess low burden of axillary disease and can avoid ALND.

Methods: We conducted a 5-year study of prospectively collected data of patients with clinically T1-2, N0 breast cancer and a positive USS-guided axillary biopsy. Primary outcome was involvement of 1-2 lymph nodes (low disease burden) or ≥3 lymph nodes (higher axillary disease) on final ALND histology. Tumour type, size, grade, multifocality, receptor status, number of abnormal imaged nodes and presence of lympho-vascular invasion (LVI) were recorded. Data were analysed using chi-squared and Student's -test.

Results: One hundred and sixty-six patients underwent ALND for pT1-2 breast cancer. Seventy patients had no clinically palpable lymphadenopathy but a positive USS-guided biopsy. Of 70 patients, 32 women (46%) had low disease burden, whereas 38 women (54%) had higher axillary disease in final histology. LVI and >1 abnormal lymph node on USS were both significantly associated with higher disease burden ( = 0.050 and 0.009, respectively).

Conclusion: Our study confirms the presence of an important patient cohort, who are clinically node-negative with a positive USS-guided biopsy and a low volume of axillary disease. No imaging modality currently has the accuracy required to identify patients with this low disease burden preoperatively but we propose a simple algorithm for axillary management in this subgroup.