Table 1.

Characteristics by mammogram interval – Breast Cancer cases age 75+ at diagnosis, excluding those with mammogram interval <= 7 mos

		All breast cancer at 75+ yrs		>7 mos to </= 2 yrs		>2 yrs to <5 yrs		>/= 5 yrs or no mammogram reported
		N	%	N	%	N	%	N	%
Breast cancer-grade	Well differentiated	498	26.02	375	26.82	91	24.46	32	22.22
	Moderately differentiated	827	43.21	602	43.06	166	44.62	59	40.97
	Poorly differentiated/anaplastic	451	23.56	318	22.75	92	24.73	41	28.47
	Unknown/not done	138	7.21	103	7.37	23	6.18	12	8.33
Summary Stage (SEER)	Localized	1477	77.17	1078	77.11	292	78.49	107	74.31
	Regional	409	21.37	304	21.75	71	19.09	34	23.61
	Distant	28	1.46	16	1.14	9	2.42	3	2.08
Estrogen receptor positive	Yes	1557	85.93	1152	86.88	299	84.94	106	79.10
	No	255	14.07	174	13.12	53	15.06	28	20.90
Her2/Neu	Positive	195	10.19	145	10.37	36	9.68	14	9.72
	Negative or borderline	1347	70.38	994	71.10	254	68.28	99	68.75
	Unknown/Not done	372	19.44	259	18.53	82	22.04	31	21.53
Diagnosis year	Before 2003	715	37.36	528	37.77	138	37.10	49	34.03
	2003 and after	1199	62.64	870	62.23	234	62.90	95	65.97
Body-mass index (kg/m2), baseline	<25	640	33.65	487	35.04	109	29.46	44	30.99
	25 – <30	687	36.12	506	36.40	138	37.30	43	30.28
	>=30	575	30.23	397	28.56	123	33.24	55	38.73
Race/ethnicity	White	1756	91.75	1278	91.42	343	92.20	135	93.75
	All other	158	8.25	120	8.58	29	7.80	9	6.25
Education level	High school diploma/GED or less	391	20.51	284	20.40	77	20.75	30	20.98
	Some school after high school	758	39.77	544	39.08	149	40.16	65	45.45
	College graduate or above	757	39.72	564	40.52	145	39.08	48	33.57
Charlson Comorbidity Index at baseline	0	1196	64.47	874	64.45	230	63.71	92	66.67
	1	423	22.80	310	22.86	84	23.27	29	21.01
	2	165	8.89	123	9.07	29	8.03	13	9.42
	3+	71	3.83	49	3.61	18	4.99	4	2.90
Ever married	No	88	4.61	69	4.95	9	2.43	10	6.94
	Yes	1820	95.39	1324	95.05	362	97.57	134	93.06
Breast biopsy at baseline	No	1278	70.45	919	69.41	257	71.99	102	76.69
	Yes	536	29.55	405	30.59	100	28.01	31	23.31
Study participation	HT Randomized	312	16.30	220	15.74	60	16.13	32	22.22
	DM Randomized and not in HT	438	22.88	304	21.75	103	27.69	31	21.53
	OS Enrolled	1164	60.82	874	62.52	209	56.18	81	56.25
Hormone trial assignment or use at baseline	Placebo/Non-user	1068	55.89	740	53.01	222	59.84	106	73.61
	Estrogen Alone	456	23.86	350	25.07	84	22.64	22	15.28
	Estrogen + Progesterone	387	20.25	306	21.92	65	17.52	16	11.11

HT - Hormone Trials

DM - Dietary Modification

OS – Observational Study