THE ROLE OF MICROMETASTASES IN NODAL COLONIZATION OF THE AXILLA IN BREAST-CANCER

The view that micrometastases are illusive prompted the recommendation that more extensive study of the nodes in the axillary specimen should be introduced in cases of breast cancer. The present study based on morphometric analysis of hilar sections from nodes from 430 axillary specimens showed that micrometastases (i.e. deposits up to 0.2 cm2), including lone micrometastases, are commonly found on routine investigation, accounting for 51% of all deposits. The size of the deposit does not reflect its extent, advanced growth being common in small nodes with micrometastases. Thus there is no need for extended investigation to identify them. It should also be remembered that modified radical mastectomy does not set out to remove all the draining nodes. The use of routine hilar rather than random nodal sections is advised. Quality control is indicated in the form of a 'second look' at the slides at the time of reporting when all appear to be tumour-free. Here immunochemistry may be useful in selected cases.