Fat clearing versus manual dissection in the processing of breast cancer axillary specimens

Erroneous understaging of breast cancer may result in less than optimal treatment. Fat clearing has been shown to increase the number of lymph nodes identified, as compared to manual dissection, but it is considerably more expensive and time consuming. In order to assess this additional yield both numerically and with regard to its impact on tumour staging, 49 consecutive axillary specimens were processed initially by hand dissection, and were then subjected to fat clearing and a second search. In 43% of the specimens additional lymph nodes were identified, 16.7% of which contained metastases. No patient was upgraded from stage I to stage II; one stage II patient (2%) was upgraded by one substage (i.e. from less than 10 to more than 10 involved nodes), qualifying her to be considered for a change in therapy (i.e. high-dose chemotherapy with autologous bone marrow transplantation, which is not yet standard therapy). We conclude that its impact on tumour staging and therapeutic decisions does not justify instituting the fat-clearing technique for routine processing of breast cancer axillary specimens, provided that the hand-dissection technique is performed diligently.