Axillary lymph node scarring and the association with tumour response following neoadjuvant chemoendocrine therapy for breast cancer.

We observed that the axillary lymph nodes of some of our breast cancer patients who received neoadjuvant chemoendocrine therapy (NCT) showed evidence of scarring. The purpose of this study is to determine whether such scarring exists and, if so, whether it is confined to neoadjuvant patients and may be related to response to therapy of the primary tumour. We examined the axillary lymph nodes of a consecutive series of 255 breast cancer patients, all of whom had undergone radical axillary dissection. Fifty-three had received NCT; the remainder formed the control group. A scar was defined as an area of cellular fibrous tissue >0.25 mm in diameter and for each patient scar count, median size and score were recorded. Nodes with scars were stained immunohistochemically (IHC) with 2 epithelial markers for the presence of occult micrometastases. The nodes of 20.7% of patients who had received NCT contained scars compared with 13.4% of controls. The median scar size was significantly greater in neoadjuvant patients (P<0.001) and within this group scar count and score were significantly higher (P=0.026 and 0.020) in those with no or minimal evidence of residual primary tumour. Scars which were IHC-positive for micrometastases were almost exclusively confined to neoadjuvant patients. Our results suggest that axillary lymph node scarring does exist, but is not a common phenomenon. It is more significant in neoadjuvant patients and within this group is most marked in those with the greatest primary tumour response to therapy. We believe that scarring is likely to represent downstaging of axillary disease. A prospective study involving a larger group of patients receiving NCT is indicated, to confirm these preliminary findings and establish whether scarring has prognostic or predictive potential.