A model of immunohistochemical differences between invasive breast cancers and DCIS lesions tested on a consecutive case series of 1248 patients

Table 1 Distributions of patients regarding breast tumor type, ER and PgR expression, HER2 overexpression and age (younger than 55, or older than 54)

	Luminal A and B1	Luminal B2	Total	Age	Luminal A and B1	Luminal B2	Total
Distribution of breast cancer patients with positive receptors according to HER2 and age
ER⁺PgR⁺	666	172	838	<55	218	69	287
ER⁺PgR⁻	66	38	104	>54	525	141	666
ER⁻PgR⁺	11	0	11	Total	743	210	953
Total	743	210	953	Total	743	210	953
Χ² (p)	13.70 (0.0002)			Χ²(p)	2.34 (0.1260)
Distribution of ductal breast cancer patients according to their steroid receptor phenotype and Ki-67 value
ER⁺ tumors without HER2	Luminal A (Ki-67 < =14%)	Luminal B1 (Ki-67 > 14%)	Total	Luminal B2	Ki-67 < =14%	Ki-67 > 14%	Total
ER⁺PgR⁺	365	301	666	ER⁺PgR⁺	49	123	172
ER⁺PgR⁻	26	40	66	ER⁺PgR⁻	9	29	38
ER⁻PgR⁺	6	5	11	ER⁻PgR⁺	0	0	0
Total	397	346	743	Total	58	152	210
Χ²(p)	5.73 (0.0167)			Χ² (p)	0.36 (0.5489)
Distribution of ductal breast cancer patients according to their age and other features
Age of Luminal A patients	ER⁺PgR⁺	ER⁺PgR⁻	ER⁻PgR⁺	Age of HER2 patients	Ki-67 < =14%	Ki-67 > 14%	Total
<55	99	5	4	<55	3	38	41
>54	266	21	2	>54	16	78	94
Total	365	26	6	Total	19	116	135
Χ²(p)	0.77 (0.3789)			Χ² (p)	2.22 (0.1360)
Age of Luminal B1 patients	ER⁺PgR⁺	ER⁺PgR⁻	ER⁻PgR⁺	Age of triple-negative patients	Ki-67 < =14%	Ki-67 > 14%	Total
<55	103	6	1	<55	7	68	75
>54	198	34	4	>54	14	71	85
Total	301	40	5	Total	21	139	160
Χ²(p)	6.00 (0.0143)			Χ² (p)	1.78 (0.1822)
Age of Luminal B2 patients	ER⁺PgR⁺	ER⁺PgR⁻	ER⁻PgR⁺	Age of patients	triple-negative	HER2	Total
<55	65	4	0	<55	75	41	116
>54	107	34	0	>54	85	94	179
Total	172	38	0	Total	160	135	295
Χ²(p)	10.49 (0.0012)			Χ² (p)	8.36 (0.0038)

The ER⁺PgR- phenotype was more common in Luminal B2 in comparison to the pooled Luminal A and B1, in Luminal B1. In Luminal B1 and in B2 ER⁺PgR- tumors were more common in patients older than 54. HER2-overexpressed patients are often older than 54.

ISSN: 1742-4682