Background: Retrieval of fewer than 10 lymph nodes at axillary dissection (ALND) for breast cancer can represent anatomic variation or inadequate dissection. We postulated that despite aggressive ALND, a lower lymph node count is more frequent after neoadjuvant chemotherapy.
Methods: Patients who received neoadjuvant chemotherapy followed by ALND were compared with patients who received surgery first. All patients received a level I and II ALND at a single institution by one of the breast surgeons. The number of nodes retrieved at ALND was dichotomized into categories (< 10 and > or = 10), and compared using Fisher exact test.
Results: A total of 143 neoadjuvant and 170 surgery-first patients were studied. Patients treated with neoadjuvant chemotherapy were significantly more likely to have fewer than 10 lymph nodes retrieved at ALND than were the surgery-first patients (19/143 or 13% vs. 6/170 or 4%, P = .003).
Conclusions: A low lymph node count is more common in patients after treatment with neoadjuvant chemotherapy and should not be assumed to represent an incomplete ALND.