The Human Epidermal Growth Factor Receptor 2 Screening Tests for Breast Cancer Suggested by the New Updated Recommendation of the American Society of Clinical Oncology/College of American Pathologists Will Involve a Rise of the In-Situ Hybridization Tests for the European Laboratories of Pathology

Table 1

Comparison between the 2007 recommendations system and the 2013 updated recommendations.

	FISH
	2007 guidelines				2013 guidelines
	E	N	P	Total	E	N	P	Total
IHC
0+	0	19	0	19	0	17	0	17
1+	7	108	3	118	0	53	1	54
2+	1	18	21	40	1	74	14	89
3+	0	0	9	9	1	1	24	26
Total	8	145	33	186	2	145	39	186

The data illustrates the increasing of 2+ IHC (resp., for 2007 and 2013 guidelines of 40 versus 89), 3+ IHC (9 versus 26), and positive HER2 FISH (33 versus 39). There are less equivocal FISH results (8 versus 2) and more false-positive 3+ IHC (0 versus 1).
FISH: fluorescence in situ hybridization, IHC: immunohistochemistry, E: equivocal, N: negative, and P: positive main changes being the increasing of 2+ and 3+ IHC or amplified HER2 FISH.