Table 3.

Luminal subtype reclassification comparing subtypes defined with tumor grade to subtypes defined with Ki67 at various cut points in 2,025 incident invasive luminal breast tumors, Nurses’ Health Study, 1976–2006

	Reclassified, n (%)
Ki67 Cut Point	No	Yes	Luminal A to B	Luminal B to A
6.7% (median)	1322 (65.3)	703 (34.7)	523 (25.8)	180 (8.9)
10%	1434 (70.8)	591 (29.2)	364 (18.0)	227 (11.2)
14%	1529 (75.5)	496 (24.5)	233 (11.5)	263 (13.0)
20%	1600 (79.0)	425 (21.0)	128 (6.3)	297 (14.7)
25%	1636 (80.8)	389 (19.2)	76 (3.8)	313 (15.5)
30%	1645 (81.2)	380 (18.8)	51 (2.5)	329 (16.3)

Percentages may not add to 100 due to rounding