Table 2. Correlation of invasive cancer size and node positivity.

Size of invasive cancer at histology (mm)	No. of patients	Node positivity at surgery (%)	Node positivity on US biopsy (%)
<10	17	2 (12%)	1 (50%)
10 – 14	39	10 (26%)	2 (20%)
15 – 19	42	16 (38%)	4 (25%)
20 – 29	45	19 (42%)	10 (53%)
>30	23	17 (74%)	10 (59%)
Total no.	166	64 (39%)	27 (42%)

In 17 patients, the primary tumour was multifocal. The sum of the sizes of all invasive foci was taken as the final measurement.