Table 1.

First appearance of clinical events observed during the follow-up period

Events	Undetectable metastases [pN0(i−), n = 328]	Nanometastases [pN0(i+), n = 24]	Micrometastases [pN1mi, n = 25]
Local recurrence	20 (17)	3 (3)	5 (4)
Contralateral breast primary	10 (6)	1 (0)	1 (1)
Second primariesa	19 (15)	3 (3)	2 (2)
Death	46 (41)	4 (4)	3 (2)
Metastases	29 (25)	7 (6)	4 (3)
Total events	124 (104)	18 (16)	15 (12)

The numbers in parentheses represent events occurred within the median follow-up time of 8 years

pN, pathologically diagnosed nodal subcategories; pN0(i−), undetectable tumor deposits; pN0(i+), lymph nodes containing isolated tumor cells (nanometastases); pN1mi, lymph nodes containing tumour foci with the largest diameter ranging between 0.2 mm and 2 mm (micrometastases)

^aOther tumours, unrelated to “early breast cancer”, which occured after its diagnosis