Table 2.

Ionizing radiation-induced cell cycle delay in breast cancer cases and controls

Family history	(N)		G2 delay index		%G2–M		G2/G0–G1		(G2/G0–G1)/S
	Control	Case	Control	Case	Control	Case	Control	Case	Control	Case
None	87	61	31.6 ± 11.5	35.1 ± 12.8	19.8 ± 4.1	19.4 ± 3.3	34.7 ± 10.9	31.9 ± 7.9	1.21 ± 0.3	1.26 ± 0.2
Mother or sister	69	11	30.1 ± 10.7	31.8 ± 12.3	19.5 ± 4.2	17.5 ± 4.3	34.3 ± 10.7	29.0 ± 10.7	1.17 ± 0.3	1.18 ± 0.2
Mother and sister	13	3	38.3 ± 17.8	51.4 ± 12.3	21.7 ± 4.3	18.9 ± 2.6	38.8 ± 9.77	28.2 ± 4.7	1.40 ± 0.3	1.34 ± 0.2
Missing	56	43	30.9 ± 10.5	37.2 ± 13.4a	19.8 ± 3.9	18.7 ± 3.4	34.2 ± 9.72	29.8 ± 8.1a	1.22 ± 0.3	1.24 ± 0.3
Total	225	118	31.4 ± 11.5	36.0 ± 13.1a	19.8 ± 4.1	19.0 ± 3.4	34.7 ± 10.5	30.8 ± 8.2a	1.21 ± 0.3	1.25 ± 0.2

Notes:

^ap < 0.001, pair-wise comparison, cases vs controls.