Table 2.

Adjusted hazard ratios for breast cancer death by IHC subtypes, grade and pTN

IHC subtype	Grade	Patients (N)/deaths (n)				pT1pN0	pT2pN0	pT1-2pN+	pT3-4pN0/+
		pT1pN0	pT2pN0	pT1-2pN+	pT3-4pN0/+
		N/n	N/n	N/n	N/n	HR [95% CI]	HR [95% CI]	HR [95% CI]	HR [95% CI]
ER+PR+HER2−	I	2498/17	225/7	592/22	30/2	1.0 [ref]	3.6 [1.5, 8.6]	4.2 [2.2, 7.9]	6.3 [1.5, 27.5]
	II	3175/36	805/23	1892/117	149/25	1.6 [0.9, 2.8]	3.6 [1.9, 6.7]	7.3 [4.4, 12.2]	15.5 [8.3, 28.9]
	III	556/25	332/24	641/83	51/16	6.4 [3.4, 11.8]	10.5 [5.6, 19.7]	16.7 [9.9, 28.2]	39.8 [20.0, 79.6]
ER+PR−HER2−	I	445/2	30/1	80/5	8/0	0.7 [0.2, 2.9]	4.3 [0.6, 32.5]	7.9 [2.9, 21.5]	N/A
	II	650/16	173/10	377/50	37/8	3.3 [1.7, 6.6]	7.5 [3.4, 16.4]	14.3 [8.2, 24.9]	24.8 [10.6, 57.9]
	III	214/11	158/16	237/46	15/3	8.5 [4.0, 18.2]	16.2 [8.2, 32.2]	24.5 [14.0, 42.9]	22.3 [6.5, 76.4]
ER+PR+HER2+/ER+PR−HER2+a	II	376/6	114/5	266/21	23/2	2.1 [0.8, 5.3]	6.0 [2.2, 16.2]	8.5 [4.4, 16.1]	7.6 [1.7, 32.8]
	III	286/12	149/12	344/26	14/3	5.6 [2.7, 11.7]	11.1 [5.3, 23.3]	9.3 [5.0, 17.2]	21.3 [6.2, 73.1]
HER2pos	II	82/1	21/1	63/7	5/2	1.3 [0.2,9.4]	7.2 [1.0, 53.8]	12.9 [5.3, 31.2]	44.5 [10.2,193.5]
	III	168/10	110/8	247/28	30/8	6.7 [3.1, 14.6]	9.2 [3.9, 21.3]	12.8 [7.0, 23.4]	27.6 [11.9, 64.4]
TNBC	II	150/6	45/7	59/12	6/3	4.8 [1.9, 12.1]	17.8 [7.4, 43.1]	22.3 [10.6, 46.8]	86.9 [25.4, 297.5]
	III	488/34	368/40	393/80	27/8	9.2 [5.1, 16.5]	14.4 [8.2, 25.5]	25.8 [15.2, 43.7]	28.5 [12.2, 66.5]

Hazard ratios adjusted for age and year of diagnosis, subtype × grade × pTN status interaction, surgery type and follow-up. Restricted to M0. N = 17,204. Test of interaction: 3-way interaction IHC subtype × grade × pTN status vs. IHC subtype × grade + pTN status, p = 0.4333. Test of interaction: 2-way interaction IHC subtype × grade + pTN status vs. IHC subtype + grade + pTN status, p = 0.0022

HER2pos ER−PR−HER2+, TNBC ER−PR−HER2−

^aER+PR+HER2+ and ER+PR−HER2+ combined into one category