Pubertal timing and breast cancer risk in the Sister Study cohort

Breast Cancer Research

Table 1 Participant characteristics by age at thelarche among 49,686 women enrolled in the Sister Study cohort

	Age at thelarche
	< 10 (N = 1743)		10–11 (N = 13,569)		12–13 (N = 25,762)		> 13 (N = 8612)
	Mean	SD	Mean	SD	Mean	SD	Mean	SD
Age at baseline, years	53.9	9.1	55.3	8.9	56.0	8.9	55.3	9.1
Bayesian family history score	0.32	0.09	0.33	0.09	0.33	0.09	0.32	0.09
Age at menarche, years	10.6	1.5	11.6	1.2	12.8	1.1	14.1	1.5
Time from thelarche to menarche, years	1.8	1.6	1.0	1.2	0.4	1.1	−0.6	1.6
Age reached adult height, years	15.0	2.9	15.5	2.5	16.3	2.2	17.2	2.1
Time from menarche to adult height, years	4.4	2.9	3.9	2.5	3.5	2.3	3.1	2.3
	n	%	n	%	n	%	n	%
Birth cohort
1928–1939	138	8	1432	11	3251	13	1047	12
1940–1949	521	30	4472	33	8592	33	2602	30
1950–1959	631	36	5052	37	9606	37	3243	38
1960–1974	453	26	2613	19	4313	17	1720	20
Race/ethnicity
Non-Hispanic white	1257	72	11,295	83	22,049	86	7050	82
Non-Hispanic black	283	16	1198	9	1952	8	880	10
Hispanic	154	9	735	5	1131	4	413	5
Others	49	3	341	3	630	2	269	3
Family income level growing up
Well-off	103	6	935	7	1628	6	511	6
Middle income	952	55	8234	61	15,548	60	4940	57
Low income	498	29	3388	25	6639	26	2362	27
Poor	190	11	1012	7	1947	8	799	9
Relative weight to peers at age 10
Lighter	298	17	3234	24	9197	36	4661	54
Same	700	40	6616	49	12,595	49	3255	38
Heavier	744	43	3693	27	3895	15	674	8
Missing	1		26		75		22
Relative height to peers at age 10
Shorter	332	19	2880	21	6612	26	2867	33
Same	649	37	6071	45	12,424	48	3633	42
Taller	760	44	4600	34	6687	26	2107	25
Missing	2		18		39		5

Column percentages are displayed. Missing data are excluded from percentages. Percentages may not add up to 100 due to rounding

ISSN: 1465-542X