MULTICENTRICITY OF BREAST-CANCER - WHOLE-ORGAN ANALYSIS AND CLINICAL IMPLICATIONS

We studied the spatial relationship within the breast between multicen tric foci (MCF) and the primary tumour in 30 modified radical mastecto my specimens using Egan's correlated pathological-radiological method using 5 mm slices of the whole breast. The relative positions within t he breast of the primary tumour and MCF were used to calculate the rel ative distribution of primary tumour rind MCF in the four quadrants of the breast and the per cent breast volume that would be required to b e excised to include all MCF. Nineteen (63%) breast harboured MCF. The relative distribution of primary tumour and MCF in the four breast qu adrants was significantly different (P=0.034). MCF were present beyond the index quadrant (25% of breast volume including the tumour) in as many as 79% (15/19) of breasts that harboured MCF; and in half the cas es (15/30) when all breast were considered. This is in variance with t he suggestion put forward previously that MCF are contained within the index quadrant in 90% of cases. Although the number of patients in th e present series is small, the probability of our finding being due to ; play of chance is 1 in 1500. In a large series of breast conservatio n studies >90% of early breast recurrences have been found to occur in the index quadrant. Our finding, that in half the patients (15/30) MC F are present in quadrants other than the index quadrant. suggests tha t MCF do not give rise to early boast recurrence.