Table 1.

Race-specific distributions of ER, PR, and HER2 status by age at diagnosis and grade; calculated among histologically confirmed female breast cancer cases in South Africa (2009–11, public sector) and Namibia (2011–13), restricted to women with known receptor status (n = 10,047 for ER, 8620 for PR, 8251 for HER2)

	Black		White		Mixed ancestry		Indian/Asian		Other/unknown
ER	N = 5,559	% ER⁻ (33.8)	N = 1,963	% ER⁻ (26.0)	N = 1,556	% ER⁻ (31.1)	N = 313	% ER⁻ (28.4)	N = 656	% ER⁻ (36.4)
Age at diagnosis
20–29	116	27.6	18	38.9	27	48.2	2	50.0	12	50.0
30–39	756	34.3	155	25.8	137	38.0	28	25.0	84	33.3
40–49	1,364	33.3	350	28.6	368	33.2	59	32.2	161	41.6
50–59	1,372	38.5	476	34.5	399	34.8	92	27.2	151	41.1
60–69	1,015	31.6	513	23.2	354	27.7	72	30.6	114	34.2
≥70	936	30.2	451	17.7	271	22.1	60	25.0	134	27.6
Grade
1	475	17.9	210	9.1	181	13.8	27	11.1	44	20.5
2	2,025	28.0	581	20.7	440	25.2	88	22.7	233	31.3
3	1,265	51.2	360	47.5	267	58.4	42	54.8	140	54.3
NK	1,794	32.3	812	24.6	668	28.7	156	27.6	239	33.9
PR^a,^b	N = 5,131	% PR⁻ (47.7)	N = 1,465	% PR⁻ (39.0)	N = 969	% PR⁻ (43.6)	N = 263	% PR⁻ (36.1)	N = 576	% PR⁻ (52.3)
Age at diagnosis
20–29	104	41.4	18	55.6	23	69.6	2	50.0	11	54.6
30–39	702	46.7	127	37.8	99	52.5	22	31.8	74	54.1
40–49	1,271	44.1	275	39.6	264	41.7	52	46.2	149	55.0
50–59	1,262	55.4	366	48.6	271	51.7	83	33.7	138	57.3
60–69	945	47.9	399	39.1	229	41.5	56	35.7	103	53.4
≥70	889	44.4	345	34.5	171	41.5	53	34.0	117	41.9
Grade^b
1	456	37.5	166	27.1	126	28.6	22	22.7	39	41.0
2	1,940	41.7	508	34.8	339	43.7	75	33.3	223	47.1
3	1,216	63.7	311	60.1	210	62.9	38	60.5	136	71.3
NK	1,561	46.5	545	38.7	382	44.0	133	33.8	194	47.9
HER2^a	N = 4,686	% HER2⁺ (24.9)	N = 1,569	% HER2⁺ (25.3)	N = 1,249	% HER2⁺ (27.6)	N = 244	% HER2⁺ (20.5)	N = 503	% HER2⁺ (24.3)
Age at diagnosis
20–29	97	24.7	14	42.93	21	19.1	2	0.0	10	10.0
30–39	636	30.7	128	25.0	109	30.3	23	34.8	66	40.9
40–49	1,140	27.3	281	31.0	287	26.5	45	22.2	131	26.0
50–59	1,176	26.5	375	25.9	343	29.5	71	14.1	116	25.9
60–69	851	21.7	412	23.5	271	24.7	58	19.03	86	12.8
≥70	786	18.1	359	21.7	218	29.4	45	24.4	94	21.3
Grade
1	413	20.8	176	17.1	146	19.1	25	12.0	36	22.2
2	1,785	24.5	511	24.3	386	25.9	76	17.1	193	27.5
3	1164	26.0	335	29.9	236	33.9	37	27.0	114	21.9
NK	1,324	25.8	547	26.1	481	28.5	106	22.6	160	23.1

↵^aPR and HER2 are included only if ER is known.
↵^bData from one laboratory (women of all ages) were excluded from total statistics for PR, due to age-related missing PR status. That laboratory included age-specific numbers; hence, the total number is less than the sum of the age-specific numbers.