TU3: WHAT IS A SAFE MARGIN?

The definition of a ‘safe’ tumour margin remains controversial. Enneking’s original definition of intralesional, marginal, wide and radical margins was based on a study of just 40 patients of whom only 12 had limb salvage surgery. Since that time thre have been numerous attempts to try and define tumour margins more clearly based on anatomical structures and distances of the tumour from the cut edge. Whilst all can agree on what is a radical margin (usually an amputation) and what is an intralesional margin (tumour exposed) there remains a lack of clear definition of what comprises a wide margin and what is a marginal margin. As an example three large tumour units were asked to assess their margins for adequacy. While the rated of adequate excision varied from 49% to 70%, all 3 units had near identical local recurrence rates of 17–20%. The rate of local recurrence is also modified by adjuvant therapy. A suggestion for an International study assessing tumour margins is made, investigating both anatomical and biological factors.